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Inheritance

1

Autosomal Recessive HP:0000007

CAH due to 21-hydroxylase deficiency and the other classic steroidogenic enzyme defects is inherited in an autosomal recessive pattern.

autosomal recessive inheritance

Show evidence (1 reference)

PMID:39911519 SUPPORT Human Clinical

"Of all congenital adrenal hyperplasia (CAH), 95% to 99% is 21-hydroxylase deficiency (21OHD), an autosomal recessive disease."

This review explicitly identifies the predominant 21-OHD form as autosomal recessive and frames its contribution to all CAH.

◆

Subtypes

9

Classic 21-hydroxylase deficiency MONDO:0008728

CYP21A2 hgnc:2600

Classic CYP21A2-related CAH with severe 21-hydroxylase deficiency; includes salt-wasting and simple-virilizing clinical forms.

Classic salt-wasting 21-hydroxylase deficiency MONDO:0017839

CYP21A2 hgnc:2600

Severe classic 21-hydroxylase deficiency with cortisol and aldosterone deficiency, neonatal salt-wasting risk, and adrenal androgen excess.

Show evidence (1 reference)

PMID:20301350 SUPPORT Human Clinical

"The classic form is further divided into the simple virilizing form (~25% of affected individuals) and the salt-wasting form, in which aldosterone production is inadequate (≥75% of individuals)."

GeneReviews gives the split of classic 21-hydroxylase deficiency between the two clinical forms. Note the denominator: these are fractions of classic 21-OHD, not of all congenital adrenal hyperplasia.

Classic simple-virilizing 21-hydroxylase deficiency MONDO:0017840

CYP21A2 hgnc:2600

Classic 21-hydroxylase deficiency with cortisol deficiency and adrenal androgen excess but less prominent mineralocorticoid deficiency.

Show evidence (1 reference)

PMID:20301350 SUPPORT Human Clinical

"The classic form is further divided into the simple virilizing form (~25% of affected individuals) and the salt-wasting form, in which aldosterone production is inadequate (≥75% of individuals)."

GeneReviews gives the split of classic 21-hydroxylase deficiency between the two clinical forms. Note the denominator: these are fractions of classic 21-OHD, not of all congenital adrenal hyperplasia.

Nonclassic congenital adrenal hyperplasia MONDO:0023601

CYP21A2 hgnc:2600

Later-onset, milder 21-hydroxylase deficiency usually presenting with hyperandrogenism rather than neonatal adrenal crisis.

11 beta-hydroxylase deficiency MONDO:0008729

CYP11B1 hgnc:2591

CAH caused by CYP11B1 deficiency, with cortisol deficiency, adrenal androgen excess, and accumulation of mineralocorticoid precursors.

17 alpha-hydroxylase/17,20-lyase deficiency MONDO:0008730

CYP17A1 hgnc:2593

CAH caused by CYP17A1 deficiency, impairing cortisol and sex-steroid synthesis with relative mineralocorticoid precursor excess.

3 beta-hydroxysteroid dehydrogenase deficiency MONDO:0008727

HSD3B2 hgnc:5218

CAH caused by HSD3B2 deficiency, disrupting glucocorticoid, mineralocorticoid, and sex-steroid synthesis.

Lipoid congenital adrenal hyperplasia MONDO:0008725

STAR hgnc:11359

Severe STAR-related steroidogenesis disorder impairing cholesterol delivery for adrenal and gonadal steroid hormone synthesis.

P450 oxidoreductase deficiency MONDO:0013310

POR hgnc:9208

CAH caused by POR deficiency. Mechanistically it is the odd one out of this family: POR is not a steroidogenic enzyme but the NADPH-dependent electron donor that every endoplasmic-reticulum cytochrome P450 requires, so a single lesion partially disables CYP17A1 and CYP21A2 together and produces a combined rather than a single-step block. The same dependency explains the features no other CAH subtype has: impaired aromatase (CYP19A1) activity can virilize the mother during pregnancy, skeletal malformation overlapping Antley-Bixler syndrome occurs, and hepatic drug metabolism is affected.

Show evidence (2 references)

PMID:33415088 SUPPORT Human Clinical

"Less frequent types of CAH are 11β-hydroxylase deficiency (CYP11B1-D, up to 8% cases), 17α-hydroxylase/17–20 lyase deficiency (CYP17A1-D), 3β-hydroxysteroid dehydrogenase deficiency (HDS3B2-D), P450 oxidoreductase deficiency (POR-D), P450 cytochrome side-chain cleavage deficiency (CYP11A1-D),..."

Names POR deficiency in this review's enumeration of the less frequent types of congenital adrenal hyperplasia. The source's typo in the 3-beta symbol (HDS3B2-D) is preserved because the snippet must be exact.

PMID:33415088 SUPPORT Human Clinical

"Maternal virilization during pregnancy, due to a defect in aromatase (CYP19A1) activity, is described in 21% of mothers"

Supports the maternal-virilization feature this row gives as one of the consequences of POR's role as a shared P450 electron donor.

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Pathophysiology

9

CYP21A2 21-Hydroxylase Deficiency

Loss of CYP21A2 21-hydroxylase activity impairs adrenal steroidogenesis, reducing cortisol and, in severe classic disease, aldosterone production. The node is the enzymatic block, not the gene lesion, and it has two inbound routes: a biallelic CYP21A2 variant, which is the usual one and the reason the node is named after the gene, and loss of electron supply from POR, which reduces the same enzyme's catalysis without any CYP21A2 variant. The node name is kept because `kb/node_classes/pathograph_node_classes.txt` cites it as a worked example.

adrenal cortical cell CL:0002097

CYP21A2 hgnc:2600

steroid biosynthetic process GO:0006694 ↓ DECREASED C21-steroid hormone biosynthetic process GO:0006700 ↓ DECREASED

Downstream

Cortisol and Aldosterone Deficiency Impaired 21-hydroxylation reduces normal glucocorticoid and, in severe classic disease, mineralocorticoid production.

Show evidence (1 reference)

PMID:39911519 SUPPORT Human Clinical

"21OHD is due to an insufficiency of 21-hydroxylase enzyme, which is encoded by the CYP21A2 gene and involved in cortisol and aldosterone production."

Establishes that CYP21A2-encoded 21-hydroxylase is required for cortisol and aldosterone production.

CYP11B1 11-Beta-Hydroxylase Deficiency

CYP11B1 pathogenic variants reduce steroid 11 beta-hydroxylase function, producing a rare CAH subtype with aberrant sex-steroid production, virilization, and mineralocorticoid precursor-mediated hypertension.

adrenal cortical cell CL:0002097

CYP11B1 hgnc:2591

steroid biosynthetic process GO:0006694 ⚠ ABNORMAL

steroid 11-beta-monooxygenase activity GO:0004507 ↓ DECREASED

Downstream

ACTH-Driven Adrenal Hyperplasia and Androgen Excess Blocked 11 beta-hydroxylase disrupts cortisol synthesis and steroid flux, promoting adrenal stimulation and androgen excess.

Hypertension Mineralocorticoid precursor accumulation in 11 beta-hydroxylase deficiency promotes hypertension.

Show evidence (2 references)

PMID:28228528 SUPPORT Human Clinical

"Congenital adrenal hyperplasia (CAH), resulting from mutations in CYP11B1, a gene encoding 11β-hydroxylase, represents a rare autosomal recessive Mendelian disorder of aberrant sex steroid production."

Supports CYP11B1 loss as a steroidogenic enzyme-deficiency mechanism in the 11B-OHD subtype.

PMID:28228528 SUPPORT Human Clinical

"Clinically, affected female newborns are profoundly virilized (Prader score of 4/5), and both genders display significantly advanced bone ages and are oftentimes hypertensive."

Links the 11 beta-hydroxylase deficiency mechanism to virilization and hypertension in the human cohort.

CYP17A1 17-Hydroxylase/17,20-Lyase Deficiency

CYP17A1 pathogenic variants reduce steroid 17 alpha-hydroxylase/17,20-lyase activity, causing a rare CAH subtype characterized by cortisol deficiency, sex-steroid deficiency, and mineralocorticoid excess. As with the CYP21A2 node, this is the enzymatic block rather than the gene lesion, and POR deficiency reaches it by removing the enzyme's electron supply rather than by altering CYP17A1 itself.

adrenal cortical cell CL:0002097

CYP17A1 hgnc:2593

steroid biosynthetic process GO:0006694 ⚠ ABNORMAL

steroid 17-alpha-monooxygenase activity GO:0004508 ↓ DECREASED

Downstream

Adrenal Insufficiency Cortisol deficiency from impaired CYP17A1 steroidogenesis contributes to adrenal insufficiency.

Hypertension Mineralocorticoid excess from impaired CYP17A1 steroidogenesis promotes hypertension.

Show evidence (1 reference)

PMID:34524979 SUPPORT Human Clinical

"17α-Hydroxylase/17,20-lyase deficiency (17OHD) caused by mutations in the CYP17A1 gene is a rare form of congenital adrenal hyperplasia typically characterised by cortisol deficiency, mineralocorticoid excess and sex steroid deficiency."

Supports CYP17A1 loss as a rare CAH mechanism with the expected cortisol, mineralocorticoid, and sex-steroid pattern.

HSD3B2 3-Beta-Hydroxysteroid Dehydrogenase Deficiency

HSD3B2 pathogenic variants reduce the adrenal and gonadal 3-beta-hydroxy-delta5-steroid dehydrogenase that converts delta-5 precursors to their delta-4 counterparts. The step is shared by the glucocorticoid, mineralocorticoid and sex-steroid branches, so unlike the 21- and 11-beta-hydroxylase blocks this one impairs gonadal as well as adrenal steroidogenesis. The placental isozyme HSD3B1 is a different gene and is not implicated.

adrenal cortical cell CL:0002097

HSD3B2 hgnc:5218

steroid hormone biosynthetic process GO:0120178 ↓ DECREASED

3-beta-hydroxy-delta5-steroid dehydrogenase activity GO:0003854 ↓ DECREASED

Downstream

Cortisol and Aldosterone Deficiency Blocking the shared delta-5 to delta-4 conversion reduces flux into both the glucocorticoid and mineralocorticoid branches.

Show evidence (3 references)

PMID:39713884 SUPPORT Human Clinical

"3β-HSD deficiency, with an incidence of less than 1/1,000,000 live births, is characterized by impairment of both adrenal and gonadal steroid biosynthesis very early in life"

Supports the combined adrenal and gonadal scope that distinguishes this node from the later single-branch enzymatic blocks.

PMID:39713884 SUPPORT Human Clinical

"Mutations in HSD3B2 cause a rare form of CAH."

Establishes HSD3B2 as the gene whose loss produces this node.

PMID:39713884 SUPPORT REVIEW SYNTHESIS Human Clinical

"In this enzyme deficiency, the production of cortisol, aldosterone, progesterone, androgens and estrogens is affected"

Substantiates this node's claim that the blocked step is shared by the glucocorticoid, mineralocorticoid and sex-steroid branches.

STAR-Dependent Mitochondrial Cholesterol Import Failure

Loss of the steroidogenic acute regulatory protein removes the delivery of cholesterol to the inner mitochondrial membrane, where side-chain cleavage begins. This node sits above every enzymatic block in this entry: the substrate never reaches the first committed step, so adrenal and gonadal steroid output fails near-completely and unesterified cholesterol accumulates as esters in the adrenal cortex, giving the lipoid form its name.

adrenal cortical cell CL:0002097

STAR hgnc:11359

intracellular cholesterol transport GO:0032367 ↓ DECREASED steroid hormone biosynthetic process GO:0120178 ↓ DECREASED

cholesterol transfer activity GO:0120020 ↓ DECREASED

Downstream

Cortisol and Aldosterone Deficiency With cholesterol not reaching the side-chain cleavage step, neither glucocorticoid nor mineralocorticoid synthesis can proceed.

Show evidence (3 references)

PMID:39713884 SUPPORT Human Clinical

"Patients with LCAH, which develops due to steroidogenic acute regulatory protein deficiency, typically present with salt wasting in the first year of life. It is characterized by complete or near-complete deficiency of adrenal and gonadal steroid hormones and progressive accumulation of..."

Supports both consequences this node asserts: near-complete steroid-output failure and cholesterol ester accumulation in the adrenal gland.

PMID:39713884 SUPPORT Human Clinical

"The classical form usually occurs with loss-of-function in the StAR gene"

Establishes STAR loss of function as the lesion behind this node.

PMID:39713884 SUPPORT REVIEW SYNTHESIS Human Clinical

"StAR-mediated transport of cholesterol to the inner mitochondrial membrane is essential for steroidogenesis."

Substantiates the cholesterol-delivery step this node's description places above every enzymatic block in the entry.

POR Electron-Transfer Failure to Microsomal P450 Enzymes

POR pathogenic variants reduce the NADPH-dependent electron donor that every endoplasmic-reticulum cytochrome P450 requires for catalysis. This is the only lesion in this entry that reaches more than one enzymatic node: the same defect partially disables CYP17A1 and CYP21A2 together, which is why POR deficiency presents as a combined rather than a single-step block, and why it also affects aromatase and hepatic drug-metabolising P450s that lie outside adrenal steroidogenesis altogether.

adrenal cortical cell CL:0002097

POR hgnc:9208

steroid hormone biosynthetic process GO:0120178 ↓ DECREASED

Downstream

CYP21A2 21-Hydroxylase Deficiency Loss of electron supply reduces CYP21A2 catalysis, producing a partial 21-hydroxylase block without a CYP21A2 variant.

CYP17A1 17-Hydroxylase/17,20-Lyase Deficiency The same electron-supply failure reduces CYP17A1 catalysis, which is why the steroid profile in POR deficiency is combined rather than isolated.

Show evidence (2 references)

PMID:33415088 SUPPORT Human Clinical

"all cytochrome P450 enzymes located in the endoplasmic reticulum get electrons for their catalytic activities from the co-factor"

States the shared-electron-donor role that makes a single POR lesion reach several steroidogenic steps.

PMID:33415088 SUPPORT Human Clinical

"The main microsomal POR-dependent enzymes are involved in the biosynthesis of steroid hormones in both the adrenal cortex and gonads (CYP17A1, CYP19A1, CYP21A2, and CYP15A1)"

Names CYP17A1 and CYP21A2 as POR-dependent, which is the evidence for the two downstream edges drawn from this node.

Cortisol and Aldosterone Deficiency

Deficient cortisol removes negative feedback on ACTH secretion; aldosterone deficiency in salt-wasting disease causes electrolyte and volume instability.

adrenal cortical cell CL:0002097

steroid biosynthetic process GO:0006694 ↓ DECREASED

Downstream

ACTH-Driven Adrenal Hyperplasia and Androgen Excess Reduced cortisol feedback increases adrenal stimulation and contributes to androgen precursor shunting.

Show evidence (1 reference)

PMID:37176569 SUPPORT Human Clinical

"CAH is characterized by the overproduction of androgen, along with variable degrees of cortisol and aldosterone deficiency."

Summarizes the core hormonal abnormalities linking cortisol and aldosterone deficiency with androgen excess.

ACTH-Driven Adrenal Hyperplasia and Androgen Excess

Persistent adrenal stimulation and blocked steroidogenic flux promote adrenal cortical hyperplasia and excess androgen production.

adrenal cortical cell CL:0002097

steroid biosynthetic process GO:0006694 ⚠ ABNORMAL

Downstream

Prenatal and Postnatal Hyperandrogenism Excess adrenal androgens produce virilization at birth in some 46,XX infants and later hyperandrogenic manifestations.

Show evidence (2 references)

PMID:39836621 SUPPORT Human Clinical

"Cortisol deficiency removes normal feedback on the hypothalamic-pituitary-adrenal axis leading to elevations in ACTH and adrenal androgen levels"

Directly supports the human mechanism: loss of cortisol feedback drives ACTH elevation, adrenal hyperplasia, and androgen excess.

PMID:38791102 SUPPORT Model Organism

"Congenital Adrenal Hyperplasia (CAH) is an autosomal recessive disorder impairing cortisol synthesis due to reduced enzymatic activity. This leads to persistent adrenocortical overstimulation and the accumulation of precursors before the blocked enzymatic step."

The humanized mouse-model abstract summarizes how reduced enzyme activity drives persistent adrenal stimulation and precursor accumulation.

Prenatal and Postnatal Hyperandrogenism

Excess adrenal androgen exposure causes prenatal genital virilization and later hyperandrogenic features such as hirsutism, acne, menstrual irregularity, and infertility.

adrenal cortical cell CL:0002097

steroid biosynthetic process GO:0006694 ↑ INCREASED

Show evidence (1 reference)

PMID:37176569 SUPPORT Human Clinical

"Non-classic CAH, a milder form of CAH, is usually manifested later in life and is a common differential diagnosis of Polycystic Ovary Syndrome and should be actively evaluated during initial studies of clinical or biochemical hyperandrogenism."

Supports late-presenting hyperandrogenism in nonclassic CAH and its clinical overlap with PCOS.

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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

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Phenotypes

11

Cardiovascular 1

Hypertension HP:0000822

Show evidence (3 references)

PMID:36857009 SUPPORT Human Clinical

"Of 73, the patients who were treated for osteoporosis/osteopaenia, hyperlipidaemia, type 2 diabetes/hyperinsulinaemia, hypertension, CV disease, obesity were 43 (59%), 17 (23%), 16 (22%), 10 (14%), 8 (11), 3 (4%) respectively."

Reports that 10 of 73 adults (14%) with classic 21-hydroxylase deficiency were treated for hypertension. Replaces a previously quoted methods sentence that only described which variables the survey collected and so established no occurrence of hypertension in CAH.

PMID:28228528 SUPPORT Human Clinical

"Clinically, affected female newborns are profoundly virilized (Prader score of 4/5), and both genders display significantly advanced bone ages and are oftentimes hypertensive."

Directly supports hypertension as a manifestation of CYP11B1-related 11 beta-hydroxylase deficiency CAH.

PMID:34524979 SUPPORT Human Clinical

"17α-Hydroxylase/17,20-lyase deficiency (17OHD) caused by mutations in the CYP17A1 gene is a rare form of congenital adrenal hyperplasia typically characterised by cortisol deficiency, mineralocorticoid excess and sex steroid deficiency."

Supports mineralocorticoid excess in CYP17A1-related CAH, the endocrine mechanism underlying hypertension in this subtype.

Endocrine 2

Adrenal Insufficiency HP:0000846

Show evidence (2 references)

PMID:37176569 SUPPORT Human Clinical

"The age at diagnosis can provide some information about underlying mutations, with those diagnosed at birth/early infancy more likely to have severe enzymatic defects, which may include adrenal insufficiency, sexual development disorders, short stature in adulthood, hirsutism, and a higher risk..."

Identifies adrenal insufficiency among severe early-diagnosed CAH manifestations.

PMID:34524979 SUPPORT Human Clinical

"17α-Hydroxylase/17,20-lyase deficiency (17OHD) caused by mutations in the CYP17A1 gene is a rare form of congenital adrenal hyperplasia typically characterised by cortisol deficiency, mineralocorticoid excess and sex steroid deficiency."

Supports cortisol deficiency, the adrenal-insufficiency component, in CYP17A1-related CAH.

Type 2 Diabetes or Hyperinsulinemia Type II diabetes mellitus HP:0005978

Show evidence (1 reference)

PMID:36857009 SUPPORT Human Clinical

"Of 73, the patients who were treated for osteoporosis/osteopaenia, hyperlipidaemia, type 2 diabetes/hyperinsulinaemia, hypertension, CV disease, obesity were 43 (59%), 17 (23%), 16 (22%), 10 (14%), 8 (11), 3 (4%) respectively."

Directly reports treated type 2 diabetes/hyperinsulinemia among adult CAH comorbidity cases.

Genitourinary 3

Ambiguous Genitalia and 46,XX Virilization HP:0000062

Onset: CONGENITAL

Show evidence (1 reference)

PMID:37176569 SUPPORT Human Clinical

"The age at diagnosis can provide some information about underlying mutations, with those diagnosed at birth/early infancy more likely to have severe enzymatic defects, which may include adrenal insufficiency, sexual development disorders, short stature in adulthood, hirsutism, and a higher risk..."

The quoted text lists "sexual development disorders" generically in severe early-diagnosed CAH; it does not document 46,XX virilization, clitoral hypertrophy, or ambiguous genitalia specifically. PARTIAL rather than SUPPORT.

Irregular Menstruation HP:0000858

Show evidence (1 reference)

PMID:37176569 SUPPORT Human Clinical

"Non-classic CAH, a milder form of CAH, is usually manifested later in life and is a common differential diagnosis of Polycystic Ovary Syndrome and should be actively evaluated during initial studies of clinical or biochemical hyperandrogenism."

The snippet supports PCOS-like hyperandrogenism; menstrual irregularity is represented as one common clinical component of that syndrome-level presentation.

Infertility HP:0000789

Show evidence (1 reference)

PMID:37176569 SUPPORT Human Clinical

"The age at diagnosis can provide some information about underlying mutations, with those diagnosed at birth/early infancy more likely to have severe enzymatic defects, which may include adrenal insufficiency, sexual development disorders, short stature in adulthood, hirsutism, and a higher risk..."

Directly lists infertility among severe CAH risks.

Integument 1

Hirsutism HP:0001007

Show evidence (1 reference)

PMID:37176569 SUPPORT Human Clinical

"The age at diagnosis can provide some information about underlying mutations, with those diagnosed at birth/early infancy more likely to have severe enzymatic defects, which may include adrenal insufficiency, sexual development disorders, short stature in adulthood, hirsutism, and a higher risk..."

Directly lists hirsutism among CAH manifestations.

Metabolism 1

Salt-Wasting Electrolyte Crisis Hyponatremia HP:0002902

Onset: NEONATAL

Show evidence (1 reference)

PMID:37176569 SUPPORT Human Clinical

"CAH is characterized by the overproduction of androgen, along with variable degrees of cortisol and aldosterone deficiency."

Establishes the aldosterone deficiency that is the upstream defect, but the quoted text does not report salt-wasting, hyponatremia, hyperkalemia, or neonatal crisis. PARTIAL rather than SUPPORT.

Musculoskeletal 1

Osteoporosis or Osteopenia HP:0000939

Show evidence (1 reference)

PMID:36857009 SUPPORT Human Clinical

"Of 73, the patients who were treated for osteoporosis/osteopaenia, hyperlipidaemia, type 2 diabetes/hyperinsulinaemia, hypertension, CV disease, obesity were 43 (59%), 17 (23%), 16 (22%), 10 (14%), 8 (11), 3 (4%) respectively."

Directly reports osteoporosis/osteopaenia treatment among adults with classic 21-hydroxylase deficiency CAH treated for comorbidities.

Growth 1

Short Stature HP:0004322

Show evidence (1 reference)

PMID:37176569 SUPPORT Human Clinical

"The age at diagnosis can provide some information about underlying mutations, with those diagnosed at birth/early infancy more likely to have severe enzymatic defects, which may include adrenal insufficiency, sexual development disorders, short stature in adulthood, hirsutism, and a higher risk..."

Directly identifies short stature in adulthood among severe CAH manifestations.

Other 1

Testicular Adrenal Rest Tumors

Show evidence (1 reference)

PMID:40921717 SUPPORT Human Clinical

"Testicular adrenal rest tumors (TART) frequently develop and are the most common cause of male infertility in classic congenital adrenal hyperplasia (CAH)."

Directly identifies TART as a frequent manifestation in classic CAH and links it to male infertility.

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Genetic Associations

6

CYP21A2 pathogenic variants (Causative)

Gene: CYP21A2 hgnc:2600 gene page relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (9 references)

PMID:39911519 SUPPORT Human Clinical

"21OHD is due to an insufficiency of 21-hydroxylase enzyme, which is encoded by the CYP21A2 gene and involved in cortisol and aldosterone production."

Directly links CYP21A2 to 21-hydroxylase deficiency.

PMID:39911519 SUPPORT Human Clinical

"Over 95% of deleterious variants leading to 21OHD are attributable to intergenic recombination events where microconversions, consisting in the transfer to CYP21A2 of deleterious variants usually present in the CYP21A1P pseudogene, represent 70% to 75%"

The quantitative basis for this record's claim that the CYP21A2 lesion is predominantly gene conversion from the CYP21A1P pseudogene rather than independent mutation.

PMID:39911519 SUPPORT Human Clinical

"A consequence of this phenomenon is that a small group of pathogenic variants with recognized phenotypic effects is detected in all populations"

Supports the first practical consequence recorded in this record's notes.

+ 6 more references

CYP11B1 pathogenic variants (Causative)

Gene: CYP11B1 hgnc:2591 gene page relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (1 reference)

PMID:28228528 SUPPORT Human Clinical

"Congenital adrenal hyperplasia (CAH), resulting from mutations in CYP11B1, a gene encoding 11β-hydroxylase, represents a rare autosomal recessive Mendelian disorder of aberrant sex steroid production."

Human cohort and structural study supports CYP11B1 variants as the disease-causing basis of the 11 beta-hydroxylase deficiency subtype.

CYP17A1 pathogenic variants (Causative)

Gene: CYP17A1 hgnc:2593 gene page relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (1 reference)

PMID:34524979 SUPPORT Human Clinical

"17α-Hydroxylase/17,20-lyase deficiency (17OHD) caused by mutations in the CYP17A1 gene is a rare form of congenital adrenal hyperplasia typically characterised by cortisol deficiency, mineralocorticoid excess and sex steroid deficiency."

Human case-series evidence directly links CYP17A1 mutations to the 17OHD CAH subtype and its steroid hormone pattern.

HSD3B2 pathogenic variants (Causative)

Gene: HSD3B2 hgnc:5218 relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (4 references)

PMID:39713884 SUPPORT Human Clinical

"Mutations in HSD3B2 cause a rare form of CAH."

Directly states that HSD3B2 variants cause a form of congenital adrenal hyperplasia.

PMID:39713884 SUPPORT Human Clinical

"HSD3B2 is expressed in the adrenal gland, ovary, and testis"

Supports the isozyme distinction recorded in this record's notes and the combined adrenal-gonadal scope of the defect.

PMID:39713884 SUPPORT REVIEW SYNTHESIS Human Clinical

"Mutations in HSD3B1 have never been reported in humans."

Substantiates this record's statement that the placental isozyme HSD3B1 is not implicated in CAH.

+ 1 more reference

STAR pathogenic variants (Causative)

Gene: STAR hgnc:11359 gene page relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (3 references)

PMID:39713884 SUPPORT Human Clinical

"The classical form usually occurs with loss-of-function in the StAR gene"

Establishes loss of STAR function as the cause of classic lipoid congenital adrenal hyperplasia.

PMID:39713884 SUPPORT Human Clinical

"Patients with LCAH, which develops due to steroidogenic acute regulatory protein deficiency, typically present with salt wasting in the first year of life. It is characterized by complete or near-complete deficiency of adrenal and gonadal steroid hormones and progressive accumulation of..."

Supports both the near-complete steroid-output failure and the cholesterol ester accumulation this record attributes to loss of cholesterol delivery.

PMID:39713884 SUPPORT Human Clinical

"Hovever in most patients with LCAH, the defect is found in StAR not the CYP11A1 gene for P450scc"

Supports this record's statement that STAR accounts for most, but not all, of clinically lipoid CAH. The source's typographic error in the first word is preserved as the snippet must be an exact quotation.

POR pathogenic variants (Causative)

Gene: POR hgnc:9208 gene page relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (4 references)

PMID:33415088 SUPPORT Human Clinical

"POR-D was first described in 2004 (59) as a rare form of CAH."

Establishes POR deficiency as a recognised form of congenital adrenal hyperplasia.

PMID:33415088 SUPPORT Human Clinical

"The main microsomal POR-dependent enzymes are involved in the biosynthesis of steroid hormones in both the adrenal cortex and gonads (CYP17A1, CYP19A1, CYP21A2, and CYP15A1)"

Names CYP17A1 and CYP21A2 among the POR-dependent enzymes, which is the basis for the two downstream edges drawn from the POR node in the pathograph.

PMID:33415088 SUPPORT Human Clinical

"The homozygous null mutations appear to be lethal"

Supports this record's statement about complete null alleles.

+ 1 more reference

💊

Medical Actions

4

Glucocorticoid replacement

Action: Pharmacotherapy NCIT:C15986

Agent: therapeutic hydrocortisone NCIT:C555

Glucocorticoid therapy replaces deficient cortisol and suppresses excess ACTH-driven adrenal androgen production; treatment must balance androgen control against glucocorticoid-related complications.

Mechanism Target:

RESTORES Cortisol and Aldosterone Deficiency — Glucocorticoid replacement restores deficient cortisol action.

INHIBITS ACTH-Driven Adrenal Hyperplasia and Androgen Excess — Adequate glucocorticoid replacement suppresses ACTH-driven adrenal androgen overproduction.

Show evidence (1 reference)

PMID:38828955 SUPPORT Human Clinical

"Adrenal insufficiency in patients with classic 21-hydroxylase deficiency congenital adrenal hyperplasia (CAH) is treated with glucocorticoid replacement therapy."

Directly supports glucocorticoid replacement as standard CAH therapy.

Mineralocorticoid replacement

Action: Pharmacotherapy NCIT:C15986

Agent: fludrocortisone NCIT:C71629

Fludrocortisone replaces mineralocorticoid activity in salt-wasting CAH and is used with glucocorticoids in many adults with classic disease.

Mechanism Target:

RESTORES Cortisol and Aldosterone Deficiency — Fludrocortisone replaces deficient mineralocorticoid action.

Target Phenotypes: hyponatremia HP:0002902

Show evidence (1 reference)

PMID:36857009 SUPPORT Human Clinical

"Of these, 126 (52%) were females and 174 (71%) received fludrocortisone in addition to glucocorticoids."

Documents frequent combined fludrocortisone and glucocorticoid treatment in adults with classic 21-hydroxylase deficiency CAH.

Crinecerfont adjunct therapy

Action: Pharmacotherapy NCIT:C15986

Agent: crinecerfont NCIT:C174708

Crinecerfont is an oral corticotropin-releasing factor type 1 receptor antagonist that reduces ACTH-driven androgen excess and enables lower glucocorticoid doses in classic CAH.

Mechanism Target:

INHIBITS ACTH-Driven Adrenal Hyperplasia and Androgen Excess — CRF1 receptor antagonism lowers ACTH drive and helps reduce adrenal androgen excess.

Show evidence (2 references)

PMID:38828955 SUPPORT Human Clinical

"Crinecerfont, an oral corticotropin-releasing factor type 1 receptor antagonist, lowered androstenedione levels in phase 2 trials involving patients with CAH."

Identifies the mechanism and prior androgen-lowering evidence for crinecerfont in CAH.

PMID:38828955 SUPPORT Human Clinical

"Among patients with CAH, the use of crinecerfont resulted in a greater decrease from baseline in the mean daily glucocorticoid dose, including a reduction to the physiologic range, than placebo following evaluation of adrenal androgen levels."

Phase 3 evidence supports a glucocorticoid-sparing benefit while monitoring adrenal androgen control.

CYP21A2 gene therapy

Action: gene therapy Ontology label: Gene Therapy NCIT:C15238

Platform: Gene therapy

AAV-mediated CYP21A2 gene therapy is investigational and is designed to restore adrenal steroidogenesis upstream of hormone deficiency and androgen shunting.

Mechanism Target:

RESTORES CYP21A2 21-Hydroxylase Deficiency — CYP21A2 delivery aims to restore the deficient steroidogenic enzyme step.

Show evidence (1 reference)

PMID:36982440 SUPPORT Other

"Congenital adrenal hyperplasia (CAH) is an example of such a potentially treatable monogenic disease."

Supports gene therapy as a plausible investigational strategy while not establishing clinical efficacy.

🔬

Biochemical Markers

2

Elevated 17-hydroxyprogesterone

Show evidence (2 references)

PMID:31984156 SUPPORT Human Clinical

"From January 2008 through December 2017, 13,376 newborns were screened for congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), and glucose-6-phosphate dehydrogenase (G6PD) deficiency at Sir Ganga Ram Hospital, India, by measuring G6PD activity, thyroid-stimulating hormone, and..."

Human population screening evidence that 17-hydroxyprogesterone is the biochemical marker measured to detect CAH. Added because this marker previously rested solely on a zebrafish model, contrary to the rule that model-organism evidence should not be the only support for a human finding.

PMID:28938470 SUPPORT Model Organism

"Furthermore, Cyp21a2-deficient larvae had a typical steroid profile, with reduced concentrations of cortisol and increased concentrations of 17-hydroxyprogesterone and 21-deoxycortisol."

The zebrafish 21OHD model recapitulates the expected steroid precursor accumulation pattern.

Reduced Cortisol

Show evidence (2 references)

PMID:37176569 SUPPORT Human Clinical

"CAH is characterized by the overproduction of androgen, along with variable degrees of cortisol and aldosterone deficiency."

Human clinical evidence for cortisol deficiency in CAH. Added because this marker previously rested solely on a mouse model whose quoted readout is corticosterone, the rodent glucocorticoid, not cortisol.

PMID:38791102 SUPPORT Model Organism

"Mutant mice showed hyperplastic adrenals and exhibited reduced levels of corticosterone and 11-deoxycorticosterone and an increase in progesterone."

The humanized mouse model reproduces blocked steroidogenesis with reduced glucocorticoid output and precursor accumulation, but the measured glucocorticoid is corticosterone (the rodent equivalent), not cortisol, so this is PARTIAL support for the human cortisol claim.

🔬

Diagnosis

2

17-hydroxyprogesterone biochemical testing

Biochemical screening and confirmatory testing for 21-hydroxylase deficiency centers on 17-hydroxyprogesterone measurement, including newborn dried-blood-spot screening in many programs.

17-hydroxyprogesterone, DBS LOINC:53340-6

Reference Ranges

17-Hydroxyprogesterone [Moles/volume] in DBS (newborn screening, North-Eastern Italy regional programme (DELFIA fluoroimmunoassay), term newborns)

Screen negative (< 30 nmol/L) Screen positive (≥ 30 nmol/L)

Screen positive: 17-OHP at or above the programme cut-off in a term newborn is a presumptive positive screen and triggers recall and confirmatory serum testing.

Source wording: "A preliminary cut-off level of > or = 30 nmol/l was set both for term and preterm newborns." The programme later set a separate, higher cut-off for preterm newborns only (next range), so 30 nmol/L is the level the source reports for term newborns. Screening cut-offs differ by programme and are stratified by maturity; this is the Italian programme's, not a universal threshold.

Show evidence (1 reference)

PMID:15818055 SUPPORT Human Clinical

"A preliminary cut-off level of > or = 30 nmol/l was set both for term and preterm newborns."

States the dried-blood-spot 17-OHP cut-off applied to term newborns by the North-Eastern Italy programme.

17-Hydroxyprogesterone [Moles/volume] in DBS (newborn screening, North-Eastern Italy regional programme (DELFIA fluoroimmunoassay), preterm newborns (gestational-age-related cut-off))

Screen negative (< 50 nmol/L) Screen positive (≥ 50 nmol/L)

Screen positive: 17-OHP at or above the preterm cut-off is a presumptive positive screen in a preterm newborn.

Source wording: "We chose a new cut-off value of 50 nmol/l for preterm newborns only". The source reports that under the single 30 nmol/L cut-off most recalled babies were preterm or low-birth-weight, and that the gestational-age-related cut-off reduced false-positive recalls among preterm babies.

Show evidence (1 reference)

PMID:15818055 SUPPORT Human Clinical

"We chose a new cut-off value of 50 nmol/l for preterm newborns only and, after 4 months, the recall rate was reduced to 0.83% for these infants and to 1.83% for low-birth-weight infants."

States the gestational-age-related preterm cut-off adopted by the same programme.

17-Hydroxyprogesterone [Moles/volume] in DBS (newborn screening, Cuba national programme (17OHP Neonatal UMELISA), samples collected on about day 5 of life)

Screen negative (< 55 nmol/L) Screen positive (≥ 55 nmol/L)

Screen positive: 17-OHP above the Cuban cut-off led to recall for confirmatory testing.

Source wording: "Confirmatory test was performed to those neonates with 17OHP values above 55 nmol/l." The source says "above", so a result exactly at 55 nmol/L was not recalled; the half-open band convention places 55 in the positive band, a one-point discrepancy noted here rather than hidden. The programme did not stratify by birth weight or gestational age during the reported period.

Show evidence (1 reference)

PMID:23481450 SUPPORT Human Clinical

"Confirmatory test was performed to those neonates with 17OHP values above 55 nmol/l."

States the recall cut-off used by the Cuban national newborn screening programme.

LOINC codes and labels were read from the Monarch KG and seeded into cache/loinc/terms.csv by scripts/seed_loinc_cache.sh. The molar DBS code is bound because every cited cut-off is in nmol/L; LOINC also carries a mass-concentration DBS code (17-Hydroxyprogesterone [Mass/volume] in DBS, LOINC:38473-5) for programmes reporting ng/mL, which is not bound here because no ng/mL cut-off is cited.

Show evidence (3 references)

PMID:31984156 SUPPORT Human Clinical

"From January 2008 through December 2017, 13,376 newborns were screened for congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), and glucose-6-phosphate dehydrogenase (G6PD) deficiency at Sir Ganga Ram Hospital, India, by measuring G6PD activity, thyroid-stimulating hormone, and..."

Demonstrates population newborn screening for CAH using dried-blood-spot 17-hydroxyprogesterone.

PMID:23481450 SUPPORT Human Clinical

"Since 2005, a newborn screening program for congenital adrenal hyperplasia (CAH) by measuring 17-alpha-hydroxyprogesterone (17OHP) in dried blood spots was introduced in Cuba."

A national programme measuring dried-blood-spot 17-OHP as the CAH screening analyte.

PMID:15818055 SUPPORT Human Clinical

"Since September 2001, blood samples from neonates born in North-Eastern Italy have been screened with a fluoroimmunoassay method for 17-OHP determination (DELFIA)."

Names the assay behind the Italian programme's cut-offs recorded above.

CYP21A2 genetic testing

Molecular testing for CYP21A2 supports diagnosis, genotype-phenotype interpretation, family counseling, and recurrence-risk assessment.

genetic testing NCIT:C15709

Show evidence (1 reference)

PMID:39911519 SUPPORT Human Clinical

"However, a genetic test to determine the CYP21A2 variants is central in confirming the 21OHD diagnosis, genetic counseling, to predict the phenotype and possibly other aspects of CAH such as long-term outcomes."

The paper's own concluding assessment of what CYP21A2 testing is for, and it covers the uses this entry claims: confirming the diagnosis, predicting the phenotype, and genetic counselling. The sentence previously quoted here said only that molecular diagnosis is complex and involves ongoing challenges, which supported none of them.

📊

Related Datasets

1

Long-Term Outcome in Offspring and Mothers of Dexamethasone-Treated Pregnancies at Risk for Classical Congenital Adrenal Hyperplasia Owing to 21-Hydroxylase Deficiency dbgap:phs001317

Summary The purpose of this study is to perform the first long-term follow up study both of adolescents and young adults with a history of prenatal treatment with dexamethasone and of their mothers and to test for adverse medical or behavioral side effects. The emphasis will be on the outcome of this prenatal treatment in those fetuses who are not affected with steroid 21-hydroxylase deficiency (21OHD) form of congenital adrenal hyperplasia (CAH) and are either heterozygotes or homozygote-unaffected. Prenatal treatment of 46,XX fetuses with 21OHD (via administration of

Located via OmicsDI, which aggregates across omics repositories; this record comes from dbgap. Only repositories with no other discovery route in this project and with a working accession resolver are curated from OmicsDI -- GEO, ArrayExpress, PRIDE, MetaboLights and EGA hits are excluded as duplicates of dedicated passes. Matched because the disease is named in the dataset's own title ("Congenital Adrenal Hyperplasia"). Retrieved 2026-08-02.

🔬

Clinical Trials

2

NCT04490915 PHASE_III ACTIVE_NOT_RECRUITING

Phase 3 trial of crinecerfont versus placebo in adults with classic CAH due to 21-hydroxylase deficiency, followed by open-label treatment.

Show evidence (1 reference)

clinicaltrials:NCT04490915 SUPPORT Human Clinical

"This is a Phase 3 study to evaluate the efficacy, safety, and tolerability of crinecerfont versus placebo administered for 24 weeks in approximately 165 adult participants with classic CAH due to 21-hydroxylase deficiency."

The trial record directly describes the crinecerfont CAH phase 3 study.

NCT04783181 PHASE_I ACTIVE_NOT_RECRUITING

Phase 1/2 first-in-human AAV5-based BBP-631 CYP21A2 gene therapy study for adults with classic CAH.

Show evidence (1 reference)

clinicaltrials:NCT04783181 SUPPORT Human Clinical

"This study is designed to evaluate the safety, tolerability, and efficacy of AAV5 based BBP-631 in adult participants diagnosed with classic congenital adrenal hyperplasia."

The trial record directly describes an AAV5 BBP-631 gene therapy study in classic CAH.

{ }

Source YAML

click to show

name: Congenital Adrenal Hyperplasia
creation_date: "2026-05-07T12:55:39Z"
category: Mendelian
synonyms:
- CAH
- adrenal hyperplasia, congenital
- adrenogenital syndrome
description: >-
  Congenital adrenal hyperplasia is a genetically heterogeneous group of
  autosomal recessive disorders of adrenal steroidogenesis in which an enzyme
  block impairs cortisol synthesis, releasing ACTH from negative feedback and
  driving adrenocortical hyperplasia with accumulation of steroid precursors
  proximal to the block. 21-hydroxylase deficiency (CYP21A2) accounts for
  95-99% of cases and shunts precursors into androgen synthesis, causing
  prenatal virilization of 46,XX infants and, in severe classic disease,
  aldosterone deficiency with neonatal salt-wasting crisis. Rarer enzyme
  defects (CYP11B1, CYP17A1, HSD3B2, STAR) produce distinct steroid patterns,
  including mineralocorticoid-precursor-driven hypertension.
notes: >-
  The curated scope emphasizes 21-hydroxylase deficiency, the overwhelmingly
  predominant form, while preserving subtype framing for the major rarer CAH
  enzyme defects.

  GeneReviews baseline: the 21-hydroxylase chapter (PMID:20301350) is the
  chapter for the dominant form and is cited on the salt-wasting and
  simple-virilizing subtype rows. There is no GeneReviews chapter for
  congenital adrenal hyperplasia as a whole; the offline Bookshelf index this
  repository commits returns only the 21-hydroxylase chapter for this entry's
  name, so the rarer enzyme defects are curated from the review literature.
disease_term:
  preferred_term: congenital adrenal hyperplasia
  term:
    id: MONDO:0018479
    label: congenital adrenal hyperplasia
parents:
- Steroid Inherited Metabolic Disorder
- Chronic Primary Adrenal Insufficiency
has_subtypes:
- name: Classic 21-OHD
  display_name: Classic 21-hydroxylase deficiency
  description: >-
    Classic CYP21A2-related CAH with severe 21-hydroxylase deficiency; includes
    salt-wasting and simple-virilizing clinical forms.
  subtype_term:
    preferred_term: classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency
    term:
      id: MONDO:0008728
      label: classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency
  genes:
  - preferred_term: CYP21A2
    term:
      id: hgnc:2600
      label: CYP21A2
- name: Salt-Wasting 21-OHD
  display_name: Classic salt-wasting 21-hydroxylase deficiency
  description: >-
    Severe classic 21-hydroxylase deficiency with cortisol and aldosterone
    deficiency, neonatal salt-wasting risk, and adrenal androgen excess.
  subtype_term:
    preferred_term: classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency, salt wasting form
    term:
      id: MONDO:0017839
      label: classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency, salt wasting form
  genes:
  - preferred_term: CYP21A2
    term:
      id: hgnc:2600
      label: CYP21A2
  evidence:
  - reference: PMID:20301350
    reference_title: 21-Hydroxylase-Deficient Congenital Adrenal Hyperplasia.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The classic form is further divided into the simple virilizing form (~25% of affected individuals) and the salt-wasting form, in which aldosterone production is inadequate (\u226575% of individuals)."
    explanation: >-
      GeneReviews gives the split of classic 21-hydroxylase deficiency between
      the two clinical forms. Note the denominator: these are fractions of
      classic 21-OHD, not of all congenital adrenal hyperplasia.
- name: Simple-Virilizing 21-OHD
  display_name: Classic simple-virilizing 21-hydroxylase deficiency
  description: >-
    Classic 21-hydroxylase deficiency with cortisol deficiency and adrenal
    androgen excess but less prominent mineralocorticoid deficiency.
  subtype_term:
    preferred_term: classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency, simple virilizing form
    term:
      id: MONDO:0017840
      label: classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency, simple virilizing form
  genes:
  - preferred_term: CYP21A2
    term:
      id: hgnc:2600
      label: CYP21A2
  evidence:
  - reference: PMID:20301350
    reference_title: 21-Hydroxylase-Deficient Congenital Adrenal Hyperplasia.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The classic form is further divided into the simple virilizing form (~25% of affected individuals) and the salt-wasting form, in which aldosterone production is inadequate (\u226575% of individuals)."
    explanation: >-
      GeneReviews gives the split of classic 21-hydroxylase deficiency between
      the two clinical forms. Note the denominator: these are fractions of
      classic 21-OHD, not of all congenital adrenal hyperplasia.
- name: Nonclassic 21-OHD
  display_name: Nonclassic congenital adrenal hyperplasia
  description: >-
    Later-onset, milder 21-hydroxylase deficiency usually presenting with
    hyperandrogenism rather than neonatal adrenal crisis.
  subtype_term:
    preferred_term: non-classic congenital adrenal hyperplasia
    term:
      id: MONDO:0023601
      label: non-classic congenital adrenal hyperplasia
  genes:
  - preferred_term: CYP21A2
    term:
      id: hgnc:2600
      label: CYP21A2
- name: 11B-OHD
  display_name: 11 beta-hydroxylase deficiency
  description: >-
    CAH caused by CYP11B1 deficiency, with cortisol deficiency, adrenal androgen
    excess, and accumulation of mineralocorticoid precursors.
  subtype_term:
    preferred_term: congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency
    term:
      id: MONDO:0008729
      label: congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency
  genes:
  - preferred_term: CYP11B1
    term:
      id: hgnc:2591
      label: CYP11B1
- name: 17A-OHD
  display_name: 17 alpha-hydroxylase/17,20-lyase deficiency
  description: >-
    CAH caused by CYP17A1 deficiency, impairing cortisol and sex-steroid
    synthesis with relative mineralocorticoid precursor excess.
  subtype_term:
    preferred_term: congenital adrenal hyperplasia due to 17-alpha-hydroxylase deficiency
    term:
      id: MONDO:0008730
      label: congenital adrenal hyperplasia due to 17-alpha-hydroxylase deficiency
  genes:
  - preferred_term: CYP17A1
    term:
      id: hgnc:2593
      label: CYP17A1
- name: 3B-HSD
  display_name: 3 beta-hydroxysteroid dehydrogenase deficiency
  description: >-
    CAH caused by HSD3B2 deficiency, disrupting glucocorticoid,
    mineralocorticoid, and sex-steroid synthesis.
  subtype_term:
    preferred_term: congenital adrenal hyperplasia due to 3-beta-hydroxysteroid dehydrogenase deficiency
    term:
      id: MONDO:0008727
      label: congenital adrenal hyperplasia due to 3-beta-hydroxysteroid dehydrogenase deficiency
  genes:
  - preferred_term: HSD3B2
    term:
      id: hgnc:5218
      label: HSD3B2
- name: Lipoid CAH
  display_name: Lipoid congenital adrenal hyperplasia
  description: >-
    Severe STAR-related steroidogenesis disorder impairing cholesterol delivery
    for adrenal and gonadal steroid hormone synthesis.
  subtype_term:
    preferred_term: congenital lipoid adrenal hyperplasia due to STAR deficiency
    term:
      id: MONDO:0008725
      label: congenital lipoid adrenal hyperplasia due to STAR deficency
  genes:
  - preferred_term: STAR
    term:
      id: hgnc:11359
      label: STAR
- name: POR-D
  display_name: P450 oxidoreductase deficiency
  description: >-
    CAH caused by POR deficiency. Mechanistically it is the odd one out of this
    family: POR is not a steroidogenic enzyme but the NADPH-dependent electron
    donor that every endoplasmic-reticulum cytochrome P450 requires, so a single
    lesion partially disables CYP17A1 and CYP21A2 together and produces a
    combined rather than a single-step block. The same dependency explains the
    features no other CAH subtype has: impaired aromatase (CYP19A1) activity can
    virilize the mother during pregnancy, skeletal malformation overlapping
    Antley-Bixler syndrome occurs, and hepatic drug metabolism is affected.
  subtype_term:
    preferred_term: congenital adrenal hyperplasia due to cytochrome P450 oxidoreductase deficiency
    term:
      id: MONDO:0013310
      label: congenital adrenal hyperplasia due to cytochrome P450 oxidoreductase deficiency
  genes:
  - preferred_term: POR
    term:
      id: hgnc:9208
      label: POR
  evidence:
  - reference: PMID:33415088
    reference_title: Congenital Adrenal Hyperplasias Presenting in the Newborn and Young Infant.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Less frequent types of CAH are 11\u03b2-hydroxylase deficiency (CYP11B1-D, up to 8% cases), 17\u03b1-hydroxylase/17\u201320 lyase deficiency (CYP17A1-D), 3\u03b2-hydroxysteroid dehydrogenase deficiency (HDS3B2-D), P450 oxidoreductase deficiency (POR-D), P450 cytochrome side-chain cleavage deficiency (CYP11A1-D), and StAR deficiency (StAR-D)."
    explanation: >-
      Names POR deficiency in this review's enumeration of the less frequent
      types of congenital adrenal hyperplasia. The source's typo in the 3-beta
      symbol (HDS3B2-D) is preserved because the snippet must be exact.
  - reference: PMID:33415088
    reference_title: Congenital Adrenal Hyperplasias Presenting in the Newborn and Young Infant.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Maternal virilization during pregnancy, due to a defect in aromatase (CYP19A1) activity, is described in 21% of mothers"
    explanation: >-
      Supports the maternal-virilization feature this row gives as one of the
      consequences of POR's role as a shared P450 electron donor.
inheritance:
- name: Autosomal Recessive
  inheritance_term:
    preferred_term: autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  description: >-
    CAH due to 21-hydroxylase deficiency and the other classic steroidogenic
    enzyme defects is inherited in an autosomal recessive pattern.
  evidence:
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Of all congenital adrenal hyperplasia (CAH), 95% to 99% is
      21-hydroxylase deficiency (21OHD), an autosomal recessive disease.
    explanation: >-
      This review explicitly identifies the predominant 21-OHD form as
      autosomal recessive and frames its contribution to all CAH.
references:
- reference: PMID:20301350
  title: "21-Hydroxylase-Deficient Congenital Adrenal Hyperplasia."
  tags:
  - GeneReviews
genetic:
- name: CYP21A2 pathogenic variants
  gene_term:
    preferred_term: CYP21A2
    term:
      id: hgnc:2600
      label: CYP21A2
  association: Causative
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  subtype: Classic 21-OHD
  features: >-
    CYP21A2 variants cause 21-hydroxylase deficiency, producing the dominant
    CAH subtype and a phenotype spectrum from classic salt-wasting disease to
    nonclassic hyperandrogenism.
  notes: >-
    The lesion type here is unlike the rest of this entry's genes. CYP21A2 sits
    in the RCCX copy-number-variable module of the MHC class III region beside
    an inactive, highly homologous pseudogene, CYP21A1P. Most disease alleles
    are therefore not independent new mutations but transfers of the
    pseudogene's own deleterious variants into the functional gene: the cited
    review attributes over 95% of deleterious 21OHD alleles to intergenic
    recombination, of which microconversions from the pseudogene are 70% to 75%
    and non-uniform meiotic crossing-over - which produces CYP21A1P/CYP21A2
    chimeric genes and a 30-kb deletion - is 20% to 25%. Only 5% to 10% of small
    pathogenic variants arise outside these recombination events.

    Two practical consequences follow and are the reason this is recorded rather
    than left implicit. First, a small recurrent set of pathogenic variants is
    seen in every population, because they are the pseudogene's variants rather
    than population-specific founder alleles. Second, the homology defeats
    ordinary sequencing: the review states that next-generation sequencing is
    not yet recommended for CYP21A2 genotyping because it can call pseudogene
    variants as gene variants, and that MLPA plus selective long-range
    amplification is the recommended approach.
  evidence:
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      21OHD is due to an insufficiency of 21-hydroxylase enzyme, which is
      encoded by the CYP21A2 gene and involved in cortisol and aldosterone
      production.
    explanation: Directly links CYP21A2 to 21-hydroxylase deficiency.
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Over 95% of deleterious variants leading to 21OHD are attributable to intergenic recombination events where microconversions, consisting in the transfer to CYP21A2 of deleterious variants usually present in the CYP21A1P pseudogene, represent 70% to 75%"
    explanation: >-
      The quantitative basis for this record's claim that the CYP21A2 lesion is
      predominantly gene conversion from the CYP21A1P pseudogene rather than
      independent mutation.
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A consequence of this phenomenon is that a small group of pathogenic variants with recognized phenotypic effects is detected in all populations"
    explanation: Supports the first practical consequence recorded in this record's notes.
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Only 5% to 10% of small pathogenic variants affecting the CYP21A2 gene are not the result of genetic conversions"
    explanation: >-
      Substantiates the residual fraction of CYP21A2 alleles that arise outside
      the gene-conversion and crossing-over mechanisms.
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A nonuniform meiotic crossing-over event is responsible for 20% to 25% of the remaining intergenic recombinations."
    explanation: >-
      Substantiates the crossing-over share, and with the microconversion figure
      above accounts for the recombination total this record states.
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "a 30-kb deletion within RCCX region, encompassing the 3\u2032 end of CYP21A1P, all the C4B gene, and the 5\u2032 end of the CYP21A2 gene, leaves the TNXB gene intact"
    explanation: Substantiates the chimeric-gene and 30-kb deletion product of the crossing-over mechanism.
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "next-generation sequencing (NGS) is not yet recommended for CYP21A2 genotyping"
    explanation: >-
      Supports the second practical consequence: the gene-pseudogene homology
      makes routine short-read sequencing unsafe for this locus.
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "NGS, in the current state of the art, can identify pathogenic variants of the pseudogene and contribute to an inadequate molecular diagnosis"
    explanation: States the specific failure mode - pseudogene variants miscalled as gene variants.
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "MLPA is recommended as the first step in 21OHD molecular diagnosis to determine the exact copy number of genes and pseudogenes within the RCCX region"
    explanation: Substantiates the recommended genotyping approach named in this record's notes.
- name: CYP11B1 pathogenic variants
  gene_term:
    preferred_term: CYP11B1
    term:
      id: hgnc:2591
      label: CYP11B1
  association: Causative
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  subtype: 11B-OHD
  features: >-
    CYP11B1 variants cause 11 beta-hydroxylase deficiency CAH.
  evidence:
  - reference: PMID:28228528
    reference_title: "Clinical, genetic, and structural basis of congenital adrenal hyperplasia due to 11β-hydroxylase deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Congenital adrenal hyperplasia (CAH), resulting from mutations in CYP11B1,
      a gene encoding 11β-hydroxylase, represents a rare autosomal recessive
      Mendelian disorder of aberrant sex steroid production.
    explanation: >-
      Human cohort and structural study supports CYP11B1 variants as the
      disease-causing basis of the 11 beta-hydroxylase deficiency subtype.
- name: CYP17A1 pathogenic variants
  gene_term:
    preferred_term: CYP17A1
    term:
      id: hgnc:2593
      label: CYP17A1
  association: Causative
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  subtype: 17A-OHD
  features: >-
    CYP17A1 variants cause 17 alpha-hydroxylase/17,20-lyase deficiency CAH.
  evidence:
  - reference: PMID:34524979
    reference_title: "The broad phenotypic spectrum of 17α-hydroxylase/17,20-lyase (CYP17A1) deficiency: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      17α-Hydroxylase/17,20-lyase deficiency (17OHD) caused by mutations in
      the CYP17A1 gene is a rare form of congenital adrenal hyperplasia
      typically characterised by cortisol deficiency, mineralocorticoid excess
      and sex steroid deficiency.
    explanation: >-
      Human case-series evidence directly links CYP17A1 mutations to the
      17OHD CAH subtype and its steroid hormone pattern.
- name: HSD3B2 pathogenic variants
  gene_term:
    preferred_term: HSD3B2
    term:
      id: hgnc:5218
      label: HSD3B2
  association: Causative
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  subtype: 3B-HSD
  features: >-
    HSD3B2 variants cause 3 beta-hydroxysteroid dehydrogenase deficiency CAH.
  notes: >-
    HSD3B2 is the adrenal and gonadal isozyme of 3-beta-hydroxysteroid
    dehydrogenase; the placental isozyme HSD3B1 is a separate gene and is not
    implicated in CAH. Because the enzyme acts at the delta-5 to delta-4
    conversion shared by all three steroid classes, the block is earlier in the
    pathway than the 21- and 11-beta-hydroxylase blocks and impairs gonadal as
    well as adrenal steroidogenesis.
  evidence:
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Mutations in HSD3B2 cause a rare form of CAH."
    explanation: Directly states that HSD3B2 variants cause a form of congenital adrenal hyperplasia.
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "HSD3B2 is expressed in the adrenal gland, ovary, and testis"
    explanation: >-
      Supports the isozyme distinction recorded in this record's notes and the
      combined adrenal-gonadal scope of the defect.
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: "Mutations in HSD3B1 have never been reported in humans."
    explanation: >-
      Substantiates this record's statement that the placental isozyme HSD3B1 is
      not implicated in CAH.
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "3β-HSD deficiency, with an incidence of less than 1/1,000,000 live births, is characterized by impairment of both adrenal and gonadal steroid biosynthesis very early in life"
    explanation: Supports the early-pathway, adrenal-and-gonadal character of the 3-beta-HSD block.
- name: STAR pathogenic variants
  gene_term:
    preferred_term: STAR
    term:
      id: hgnc:11359
      label: STAR
  association: Causative
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  subtype: Lipoid CAH
  features: >-
    STAR variants cause lipoid congenital adrenal hyperplasia by impairing
    cholesterol delivery for steroidogenesis.
  notes: >-
    STAR is the one gene in this entry that encodes neither an enzyme nor an
    enzyme's electron donor: the steroidogenic acute regulatory protein delivers
    cholesterol to the inner mitochondrial membrane, so its loss starves the
    first committed step rather than blocking a later one. That places the
    defect above every enzymatic block modelled here and explains the
    near-complete loss of adrenal and gonadal steroid output and the cholesterol
    ester accumulation that gives the lipoid form its name. A minority of
    clinically lipoid CAH is due to CYP11A1 rather than STAR; MONDO has no
    congenital-adrenal-hyperplasia child term for the CYP11A1 form (its only
    CYP11A1 CAH classes are non-human-animal ones), so no subtype row is
    recorded for it here.
  evidence:
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The classical form usually occurs with loss-of-function in the StAR gene"
    explanation: Establishes loss of STAR function as the cause of classic lipoid congenital adrenal hyperplasia.
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients with LCAH, which develops due to steroidogenic acute regulatory protein deficiency, typically present with salt wasting in the first year of life. It is characterized by complete or near-complete deficiency of adrenal and gonadal steroid hormones and progressive accumulation of cholesterol esters in the adrenal gland."
    explanation: >-
      Supports both the near-complete steroid-output failure and the cholesterol
      ester accumulation this record attributes to loss of cholesterol delivery.
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hovever in most patients with LCAH, the defect is found in StAR not the CYP11A1 gene for P450scc"
    explanation: >-
      Supports this record's statement that STAR accounts for most, but not all,
      of clinically lipoid CAH. The source's typographic error in the first word
      is preserved as the snippet must be an exact quotation.
- name: POR pathogenic variants
  gene_term:
    preferred_term: POR
    term:
      id: hgnc:9208
      label: POR
  association: Causative
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  subtype: POR-D
  features: >-
    POR variants cause P450 oxidoreductase deficiency, a combined form of CAH.
  notes: >-
    POR encodes the NADPH-dependent electron donor shared by the
    endoplasmic-reticulum cytochrome P450 enzymes, so its loss partially
    disables several steroidogenic steps at once rather than one. Within this
    entry that makes POR the only gene whose lesion reaches more than one
    enzymatic node, which is how it is wired in the pathograph. Complete null
    alleles appear not to be compatible with life.
  evidence:
  - reference: PMID:33415088
    reference_title: Congenital Adrenal Hyperplasias Presenting in the Newborn and Young Infant.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "POR-D was first described in 2004 (59) as a rare form of CAH."
    explanation: Establishes POR deficiency as a recognised form of congenital adrenal hyperplasia.
  - reference: PMID:33415088
    reference_title: Congenital Adrenal Hyperplasias Presenting in the Newborn and Young Infant.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The main microsomal POR-dependent enzymes are involved in the biosynthesis of steroid hormones in both the adrenal cortex and gonads (CYP17A1, CYP19A1, CYP21A2, and CYP15A1)"
    explanation: >-
      Names CYP17A1 and CYP21A2 among the POR-dependent enzymes, which is the
      basis for the two downstream edges drawn from the POR node in the
      pathograph.
  - reference: PMID:33415088
    reference_title: Congenital Adrenal Hyperplasias Presenting in the Newborn and Young Infant.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The homozygous null mutations appear to be lethal"
    explanation: Supports this record's statement about complete null alleles.
  - reference: CGGV:assertion_6275d46a-f005-45f8-b3ec-e9722f8dd39e-2022-03-23T193729.312Z
    reference_title: "POR / Antley-Bixler syndrome with genital anomalies and disordered steroidogenesis (Definitive)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "POR | HGNC:9208 | Antley-Bixler syndrome with genital anomalies and disordered steroidogenesis | MONDO:0008726 | AR | Definitive"
    explanation: >-
      ClinGen classifies POR as definitive with autosomal recessive inheritance.
      The assertion is scoped to the Antley-Bixler-with-disordered-steroidogenesis
      label rather than to the CAH label, which reflects the skeletal-plus-steroid
      phenotype this record describes rather than a different gene-disease claim.
pathophysiology:
- name: CYP21A2 21-Hydroxylase Deficiency
  description: >-
    Loss of CYP21A2 21-hydroxylase activity impairs adrenal steroidogenesis,
    reducing cortisol and, in severe classic disease, aldosterone production.
    The node is the enzymatic block, not the gene lesion, and it has two inbound
    routes: a biallelic CYP21A2 variant, which is the usual one and the reason
    the node is named after the gene, and loss of electron supply from POR,
    which reduces the same enzyme's catalysis without any CYP21A2 variant. The
    node name is kept because `kb/node_classes/pathograph_node_classes.txt`
    cites it as a worked example.
  genes:
  - preferred_term: CYP21A2
    term:
      id: hgnc:2600
      label: CYP21A2
  cell_types:
  - preferred_term: adrenal cortical cell
    term:
      id: CL:0002097
      label: cortical cell of adrenal gland
  biological_processes:
  - preferred_term: steroid biosynthetic process
    term:
      id: GO:0006694
      label: steroid biosynthetic process
    modifier: DECREASED
  - preferred_term: C21-steroid hormone biosynthetic process
    term:
      id: GO:0006700
      label: C21-steroid hormone biosynthetic process
    modifier: DECREASED
  evidence:
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      21OHD is due to an insufficiency of 21-hydroxylase enzyme, which is
      encoded by the CYP21A2 gene and involved in cortisol and aldosterone
      production.
    explanation: >-
      Establishes that CYP21A2-encoded 21-hydroxylase is required for cortisol
      and aldosterone production.
  downstream:
  - target: Cortisol and Aldosterone Deficiency
    description: >-
      Impaired 21-hydroxylation reduces normal glucocorticoid and, in severe
      classic disease, mineralocorticoid production.
- name: CYP11B1 11-Beta-Hydroxylase Deficiency
  description: >-
    CYP11B1 pathogenic variants reduce steroid 11 beta-hydroxylase function,
    producing a rare CAH subtype with aberrant sex-steroid production,
    virilization, and mineralocorticoid precursor-mediated hypertension.
  genes:
  - preferred_term: CYP11B1
    term:
      id: hgnc:2591
      label: CYP11B1
  cell_types:
  - preferred_term: adrenal cortical cell
    term:
      id: CL:0002097
      label: cortical cell of adrenal gland
  molecular_functions:
  - preferred_term: steroid 11-beta-monooxygenase activity
    term:
      id: GO:0004507
      label: steroid 11-beta-monooxygenase activity
    modifier: DECREASED
  biological_processes:
  - preferred_term: steroid biosynthetic process
    term:
      id: GO:0006694
      label: steroid biosynthetic process
    modifier: ABNORMAL
  evidence:
  - reference: PMID:28228528
    reference_title: "Clinical, genetic, and structural basis of congenital adrenal hyperplasia due to 11β-hydroxylase deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Congenital adrenal hyperplasia (CAH), resulting from mutations in CYP11B1,
      a gene encoding 11β-hydroxylase, represents a rare autosomal recessive
      Mendelian disorder of aberrant sex steroid production.
    explanation: >-
      Supports CYP11B1 loss as a steroidogenic enzyme-deficiency mechanism in
      the 11B-OHD subtype.
  - reference: PMID:28228528
    reference_title: "Clinical, genetic, and structural basis of congenital adrenal hyperplasia due to 11β-hydroxylase deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Clinically, affected female newborns are profoundly virilized (Prader
      score of 4/5), and both genders display significantly advanced bone ages
      and are oftentimes hypertensive.
    explanation: >-
      Links the 11 beta-hydroxylase deficiency mechanism to virilization and
      hypertension in the human cohort.
  downstream:
  - target: ACTH-Driven Adrenal Hyperplasia and Androgen Excess
    description: >-
      Blocked 11 beta-hydroxylase disrupts cortisol synthesis and steroid flux,
      promoting adrenal stimulation and androgen excess.
  - target: Hypertension
    description: >-
      Mineralocorticoid precursor accumulation in 11 beta-hydroxylase deficiency
      promotes hypertension.
- name: CYP17A1 17-Hydroxylase/17,20-Lyase Deficiency
  description: >-
    CYP17A1 pathogenic variants reduce steroid 17 alpha-hydroxylase/17,20-lyase
    activity, causing a rare CAH subtype characterized by cortisol deficiency,
    sex-steroid deficiency, and mineralocorticoid excess. As with the CYP21A2
    node, this is the enzymatic block rather than the gene lesion, and POR
    deficiency reaches it by removing the enzyme's electron supply rather than
    by altering CYP17A1 itself.
  genes:
  - preferred_term: CYP17A1
    term:
      id: hgnc:2593
      label: CYP17A1
  cell_types:
  - preferred_term: adrenal cortical cell
    term:
      id: CL:0002097
      label: cortical cell of adrenal gland
  molecular_functions:
  - preferred_term: steroid 17-alpha-monooxygenase activity
    term:
      id: GO:0004508
      label: steroid 17-alpha-monooxygenase activity
    modifier: DECREASED
  biological_processes:
  - preferred_term: steroid biosynthetic process
    term:
      id: GO:0006694
      label: steroid biosynthetic process
    modifier: ABNORMAL
  evidence:
  - reference: PMID:34524979
    reference_title: "The broad phenotypic spectrum of 17α-hydroxylase/17,20-lyase (CYP17A1) deficiency: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      17α-Hydroxylase/17,20-lyase deficiency (17OHD) caused by mutations in
      the CYP17A1 gene is a rare form of congenital adrenal hyperplasia
      typically characterised by cortisol deficiency, mineralocorticoid excess
      and sex steroid deficiency.
    explanation: >-
      Supports CYP17A1 loss as a rare CAH mechanism with the expected cortisol,
      mineralocorticoid, and sex-steroid pattern.
  downstream:
  - target: Adrenal Insufficiency
    description: >-
      Cortisol deficiency from impaired CYP17A1 steroidogenesis contributes to
      adrenal insufficiency.
  - target: Hypertension
    description: >-
      Mineralocorticoid excess from impaired CYP17A1 steroidogenesis promotes
      hypertension.
- name: HSD3B2 3-Beta-Hydroxysteroid Dehydrogenase Deficiency
  description: >-
    HSD3B2 pathogenic variants reduce the adrenal and gonadal
    3-beta-hydroxy-delta5-steroid dehydrogenase that converts delta-5 precursors
    to their delta-4 counterparts. The step is shared by the glucocorticoid,
    mineralocorticoid and sex-steroid branches, so unlike the 21- and
    11-beta-hydroxylase blocks this one impairs gonadal as well as adrenal
    steroidogenesis. The placental isozyme HSD3B1 is a different gene and is not
    implicated.
  genes:
  - preferred_term: HSD3B2
    term:
      id: hgnc:5218
      label: HSD3B2
  cell_types:
  - preferred_term: adrenal cortical cell
    term:
      id: CL:0002097
      label: cortical cell of adrenal gland
  molecular_functions:
  - preferred_term: 3-beta-hydroxy-delta5-steroid dehydrogenase activity
    term:
      id: GO:0003854
      label: 3-beta-hydroxy-Delta5-steroid dehydrogenase (NAD+) activity
    modifier: DECREASED
  biological_processes:
  - preferred_term: steroid hormone biosynthetic process
    term:
      id: GO:0120178
      label: steroid hormone biosynthetic process
    modifier: DECREASED
  evidence:
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "3β-HSD deficiency, with an incidence of less than 1/1,000,000 live births, is characterized by impairment of both adrenal and gonadal steroid biosynthesis very early in life"
    explanation: >-
      Supports the combined adrenal and gonadal scope that distinguishes this
      node from the later single-branch enzymatic blocks.
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Mutations in HSD3B2 cause a rare form of CAH."
    explanation: Establishes HSD3B2 as the gene whose loss produces this node.
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: "In this enzyme deficiency, the production of cortisol, aldosterone, progesterone, androgens and estrogens is affected"
    explanation: >-
      Substantiates this node's claim that the blocked step is shared by the
      glucocorticoid, mineralocorticoid and sex-steroid branches.
  downstream:
  - target: Cortisol and Aldosterone Deficiency
    description: >-
      Blocking the shared delta-5 to delta-4 conversion reduces flux into both
      the glucocorticoid and mineralocorticoid branches.
    causal_link_type: DIRECT
- name: STAR-Dependent Mitochondrial Cholesterol Import Failure
  description: >-
    Loss of the steroidogenic acute regulatory protein removes the delivery of
    cholesterol to the inner mitochondrial membrane, where side-chain cleavage
    begins. This node sits above every enzymatic block in this entry: the
    substrate never reaches the first committed step, so adrenal and gonadal
    steroid output fails near-completely and unesterified cholesterol
    accumulates as esters in the adrenal cortex, giving the lipoid form its
    name.
  genes:
  - preferred_term: STAR
    term:
      id: hgnc:11359
      label: STAR
  cell_types:
  - preferred_term: adrenal cortical cell
    term:
      id: CL:0002097
      label: cortical cell of adrenal gland
  molecular_functions:
  - preferred_term: cholesterol transfer activity
    term:
      id: GO:0120020
      label: cholesterol transfer activity
    modifier: DECREASED
  biological_processes:
  - preferred_term: intracellular cholesterol transport
    term:
      id: GO:0032367
      label: intracellular cholesterol transport
    modifier: DECREASED
  - preferred_term: steroid hormone biosynthetic process
    term:
      id: GO:0120178
      label: steroid hormone biosynthetic process
    modifier: DECREASED
  chemical_entities:
  - preferred_term: cholesterol
    term:
      id: CHEBI:16113
      label: cholesterol
  evidence:
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients with LCAH, which develops due to steroidogenic acute regulatory protein deficiency, typically present with salt wasting in the first year of life. It is characterized by complete or near-complete deficiency of adrenal and gonadal steroid hormones and progressive accumulation of cholesterol esters in the adrenal gland."
    explanation: >-
      Supports both consequences this node asserts: near-complete steroid-output
      failure and cholesterol ester accumulation in the adrenal gland.
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The classical form usually occurs with loss-of-function in the StAR gene"
    explanation: Establishes STAR loss of function as the lesion behind this node.
  - reference: PMID:39713884
    reference_title: Rare Types of Congenital Adrenal Hyperplasias Other Than 21-hydroxylase Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: "StAR-mediated transport of cholesterol to the inner mitochondrial membrane is essential for steroidogenesis."
    explanation: >-
      Substantiates the cholesterol-delivery step this node's description places
      above every enzymatic block in the entry.
  downstream:
  - target: Cortisol and Aldosterone Deficiency
    description: >-
      With cholesterol not reaching the side-chain cleavage step, neither
      glucocorticoid nor mineralocorticoid synthesis can proceed.
    causal_link_type: DIRECT
- name: POR Electron-Transfer Failure to Microsomal P450 Enzymes
  description: >-
    POR pathogenic variants reduce the NADPH-dependent electron donor that every
    endoplasmic-reticulum cytochrome P450 requires for catalysis. This is the
    only lesion in this entry that reaches more than one enzymatic node: the
    same defect partially disables CYP17A1 and CYP21A2 together, which is why
    POR deficiency presents as a combined rather than a single-step block, and
    why it also affects aromatase and hepatic drug-metabolising P450s that lie
    outside adrenal steroidogenesis altogether.
  genes:
  - preferred_term: POR
    term:
      id: hgnc:9208
      label: POR
  cell_types:
  - preferred_term: adrenal cortical cell
    term:
      id: CL:0002097
      label: cortical cell of adrenal gland
  biological_processes:
  - preferred_term: steroid hormone biosynthetic process
    term:
      id: GO:0120178
      label: steroid hormone biosynthetic process
    modifier: DECREASED
  evidence:
  - reference: PMID:33415088
    reference_title: Congenital Adrenal Hyperplasias Presenting in the Newborn and Young Infant.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "all cytochrome P450 enzymes located in the endoplasmic reticulum get electrons for their catalytic activities from the co-factor"
    explanation: >-
      States the shared-electron-donor role that makes a single POR lesion reach
      several steroidogenic steps.
  - reference: PMID:33415088
    reference_title: Congenital Adrenal Hyperplasias Presenting in the Newborn and Young Infant.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The main microsomal POR-dependent enzymes are involved in the biosynthesis of steroid hormones in both the adrenal cortex and gonads (CYP17A1, CYP19A1, CYP21A2, and CYP15A1)"
    explanation: >-
      Names CYP17A1 and CYP21A2 as POR-dependent, which is the evidence for the
      two downstream edges drawn from this node.
  downstream:
  - target: CYP21A2 21-Hydroxylase Deficiency
    description: >-
      Loss of electron supply reduces CYP21A2 catalysis, producing a partial
      21-hydroxylase block without a CYP21A2 variant.
    causal_link_type: DIRECT
  - target: CYP17A1 17-Hydroxylase/17,20-Lyase Deficiency
    description: >-
      The same electron-supply failure reduces CYP17A1 catalysis, which is why
      the steroid profile in POR deficiency is combined rather than isolated.
    causal_link_type: DIRECT
- name: Cortisol and Aldosterone Deficiency
  description: >-
    Deficient cortisol removes negative feedback on ACTH secretion; aldosterone
    deficiency in salt-wasting disease causes electrolyte and volume
    instability.
  cell_types:
  - preferred_term: adrenal cortical cell
    term:
      id: CL:0002097
      label: cortical cell of adrenal gland
  chemical_entities:
  - preferred_term: cortisol
    term:
      id: CHEBI:17650
      label: cortisol
  - preferred_term: aldosterone
    term:
      id: CHEBI:27584
      label: aldosterone
  biological_processes:
  - preferred_term: steroid biosynthetic process
    term:
      id: GO:0006694
      label: steroid biosynthetic process
    modifier: DECREASED
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      CAH is characterized by the overproduction of androgen, along with
      variable degrees of cortisol and aldosterone deficiency.
    explanation: >-
      Summarizes the core hormonal abnormalities linking cortisol and
      aldosterone deficiency with androgen excess.
  downstream:
  - target: ACTH-Driven Adrenal Hyperplasia and Androgen Excess
    description: >-
      Reduced cortisol feedback increases adrenal stimulation and contributes
      to androgen precursor shunting.
- name: ACTH-Driven Adrenal Hyperplasia and Androgen Excess
  description: >-
    Persistent adrenal stimulation and blocked steroidogenic flux promote
    adrenal cortical hyperplasia and excess androgen production.
  cell_types:
  - preferred_term: adrenal cortical cell
    term:
      id: CL:0002097
      label: cortical cell of adrenal gland
  biological_processes:
  - preferred_term: steroid biosynthetic process
    term:
      id: GO:0006694
      label: steroid biosynthetic process
    modifier: ABNORMAL
  evidence:
  - reference: PMID:39836621
    reference_title: "Genetics and Pathophysiology of Classic Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cortisol deficiency removes normal feedback on the hypothalamic-pituitary-adrenal axis leading to elevations in ACTH and adrenal androgen levels"
    explanation: >-
      Directly supports the human mechanism: loss of cortisol feedback drives
      ACTH elevation, adrenal hyperplasia, and androgen excess.
  - reference: PMID:38791102
    reference_title: "A Humanized and Viable Animal Model for Congenital Adrenal Hyperplasia-CYP21A2-R484Q Mutant Mouse."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Congenital Adrenal Hyperplasia (CAH) is an autosomal recessive disorder
      impairing cortisol synthesis due to reduced enzymatic activity. This leads
      to persistent adrenocortical overstimulation and the accumulation of
      precursors before the blocked enzymatic step.
    explanation: >-
      The humanized mouse-model abstract summarizes how reduced enzyme activity
      drives persistent adrenal stimulation and precursor accumulation.
  downstream:
  - target: Prenatal and Postnatal Hyperandrogenism
    description: >-
      Excess adrenal androgens produce virilization at birth in some 46,XX
      infants and later hyperandrogenic manifestations.
- name: Prenatal and Postnatal Hyperandrogenism
  description: >-
    Excess adrenal androgen exposure causes prenatal genital virilization and
    later hyperandrogenic features such as hirsutism, acne, menstrual
    irregularity, and infertility.
  cell_types:
  - preferred_term: adrenal cortical cell
    term:
      id: CL:0002097
      label: cortical cell of adrenal gland
  biological_processes:
  - preferred_term: steroid biosynthetic process
    term:
      id: GO:0006694
      label: steroid biosynthetic process
    modifier: INCREASED
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Non-classic CAH, a milder form of CAH, is usually manifested later in life
      and is a common differential diagnosis of Polycystic Ovary Syndrome and
      should be actively evaluated during initial studies of clinical or
      biochemical hyperandrogenism.
    explanation: >-
      Supports late-presenting hyperandrogenism in nonclassic CAH and its
      clinical overlap with PCOS.
phenotypes:
- category: Endocrine
  name: Adrenal Insufficiency
  description: >-
    Cortisol deficiency is a core feature of classic CAH and can present in
    neonates or early infancy in severe forms; rare enzyme defects such as
    CYP17A1 deficiency can also produce cortisol deficiency.
  phenotype_term:
    preferred_term: Adrenal insufficiency
    term:
      id: HP:0000846
      label: Adrenal insufficiency
  subtypes:
  - Classic 21-OHD
  - Salt-Wasting 21-OHD
  - Simple-Virilizing 21-OHD
  - 17A-OHD
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The age at diagnosis can provide some information about underlying
      mutations, with those diagnosed at birth/early infancy more likely to have
      severe enzymatic defects, which may include adrenal insufficiency, sexual
      development disorders, short stature in adulthood, hirsutism, and a higher
      risk for metabolic syndrome and infertility.
    explanation: >-
      Identifies adrenal insufficiency among severe early-diagnosed CAH
      manifestations.
  - reference: PMID:34524979
    reference_title: "The broad phenotypic spectrum of 17α-hydroxylase/17,20-lyase (CYP17A1) deficiency: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      17α-Hydroxylase/17,20-lyase deficiency (17OHD) caused by mutations in
      the CYP17A1 gene is a rare form of congenital adrenal hyperplasia
      typically characterised by cortisol deficiency, mineralocorticoid excess
      and sex steroid deficiency.
    explanation: >-
      Supports cortisol deficiency, the adrenal-insufficiency component, in
      CYP17A1-related CAH.
- category: Endocrine
  name: Salt-Wasting Electrolyte Crisis
  description: >-
    Severe mineralocorticoid deficiency can cause neonatal salt-wasting with
    hyponatremia, hyperkalemia, hypovolemia, and risk of shock.
  phenotype_term:
    preferred_term: hyponatremia
    term:
      id: HP:0002902
      label: Hyponatremia
    onset:
      onset_category: NEONATAL
  subtypes:
  - Salt-Wasting 21-OHD
  - 3B-HSD
  - Lipoid CAH
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      CAH is characterized by the overproduction of androgen, along with
      variable degrees of cortisol and aldosterone deficiency.
    explanation: >-
      Establishes the aldosterone deficiency that is the upstream defect, but the
      quoted text does not report salt-wasting, hyponatremia, hyperkalemia, or
      neonatal crisis. PARTIAL rather than SUPPORT.
- category: Genitourinary
  name: Ambiguous Genitalia and 46,XX Virilization
  description: >-
    Prenatal androgen excess can virilize external genitalia in affected 46,XX
    infants, including clitoral hypertrophy or ambiguous genitalia.
  phenotype_term:
    preferred_term: Ambiguous genitalia
    term:
      id: HP:0000062
      label: Ambiguous genitalia
    onset:
      onset_category: CONGENITAL
  subtypes:
  - Classic 21-OHD
  - Salt-Wasting 21-OHD
  - Simple-Virilizing 21-OHD
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The age at diagnosis can provide some information about underlying
      mutations, with those diagnosed at birth/early infancy more likely to have
      severe enzymatic defects, which may include adrenal insufficiency, sexual
      development disorders, short stature in adulthood, hirsutism, and a higher
      risk for metabolic syndrome and infertility.
    explanation: >-
      The quoted text lists "sexual development disorders" generically in severe
      early-diagnosed CAH; it does not document 46,XX virilization, clitoral
      hypertrophy, or ambiguous genitalia specifically. PARTIAL rather than
      SUPPORT.
- category: Endocrine
  name: Hirsutism
  description: >-
    Androgen excess can cause hirsutism, especially in simple-virilizing and
    nonclassic 21-hydroxylase deficiency.
  phenotype_term:
    preferred_term: Hirsutism
    term:
      id: HP:0001007
      label: Hirsutism
  subtypes:
  - Simple-Virilizing 21-OHD
  - Nonclassic 21-OHD
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The age at diagnosis can provide some information about underlying
      mutations, with those diagnosed at birth/early infancy more likely to have
      severe enzymatic defects, which may include adrenal insufficiency, sexual
      development disorders, short stature in adulthood, hirsutism, and a higher
      risk for metabolic syndrome and infertility.
    explanation: Directly lists hirsutism among CAH manifestations.
- category: Endocrine
  name: Irregular Menstruation
  description: >-
    Hyperandrogenism in nonclassic CAH may cause menstrual irregularity and
    PCOS-like reproductive endocrine presentations.
  phenotype_term:
    preferred_term: Irregular menstruation
    term:
      id: HP:0000858
      label: Irregular menstruation
  subtypes:
  - Nonclassic 21-OHD
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Non-classic CAH, a milder form of CAH, is usually manifested later in life
      and is a common differential diagnosis of Polycystic Ovary Syndrome and
      should be actively evaluated during initial studies of clinical or
      biochemical hyperandrogenism.
    explanation: >-
      The snippet supports PCOS-like hyperandrogenism; menstrual irregularity is
      represented as one common clinical component of that syndrome-level
      presentation.
- category: Reproductive
  name: Infertility
  description: >-
    Chronic androgen excess, adrenal rest tissue, and treatment balance can
    affect fertility in classic and nonclassic CAH.
  phenotype_term:
    preferred_term: Infertility
    term:
      id: HP:0000789
      label: Infertility
  subtypes:
  - Classic 21-OHD
  - Nonclassic 21-OHD
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The age at diagnosis can provide some information about underlying
      mutations, with those diagnosed at birth/early infancy more likely to have
      severe enzymatic defects, which may include adrenal insufficiency, sexual
      development disorders, short stature in adulthood, hirsutism, and a higher
      risk for metabolic syndrome and infertility.
    explanation: Directly lists infertility among severe CAH risks.
- category: Cardiometabolic
  name: Hypertension
  description: >-
    Adults with classic 21-hydroxylase deficiency require surveillance for
    cardiometabolic morbidity, including hypertension; hypertension also occurs
    in mineralocorticoid-excess CAH mechanisms such as 11 beta-hydroxylase
    deficiency and 17 alpha-hydroxylase/17,20-lyase deficiency.
  phenotype_term:
    preferred_term: Hypertension
    term:
      id: HP:0000822
      label: Hypertension
  subtypes:
  - Classic 21-OHD
  - 11B-OHD
  - 17A-OHD
  evidence:
  - reference: PMID:36857009
    reference_title: "Long-term cardiometabolic morbidity in young adults with classic 21-hydroxylase deficiency congenital adrenal hyperplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Of 73, the patients who were treated for osteoporosis/osteopaenia,
      hyperlipidaemia, type 2 diabetes/hyperinsulinaemia, hypertension, CV
      disease, obesity were 43 (59%), 17 (23%), 16 (22%), 10 (14%), 8 (11), 3
      (4%) respectively.
    explanation: >-
      Reports that 10 of 73 adults (14%) with classic 21-hydroxylase deficiency
      were treated for hypertension. Replaces a previously quoted methods
      sentence that only described which variables the survey collected and so
      established no occurrence of hypertension in CAH.
  - reference: PMID:28228528
    reference_title: "Clinical, genetic, and structural basis of congenital adrenal hyperplasia due to 11β-hydroxylase deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Clinically, affected female newborns are profoundly virilized (Prader
      score of 4/5), and both genders display significantly advanced bone ages
      and are oftentimes hypertensive.
    explanation: >-
      Directly supports hypertension as a manifestation of CYP11B1-related
      11 beta-hydroxylase deficiency CAH.
  - reference: PMID:34524979
    reference_title: "The broad phenotypic spectrum of 17α-hydroxylase/17,20-lyase (CYP17A1) deficiency: a case series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      17α-Hydroxylase/17,20-lyase deficiency (17OHD) caused by mutations in
      the CYP17A1 gene is a rare form of congenital adrenal hyperplasia
      typically characterised by cortisol deficiency, mineralocorticoid excess
      and sex steroid deficiency.
    explanation: >-
      Supports mineralocorticoid excess in CYP17A1-related CAH, the endocrine
      mechanism underlying hypertension in this subtype.
- category: Skeletal
  name: Osteoporosis or Osteopenia
  description: >-
    Long-term glucocorticoid exposure and disease management challenges can be
    associated with low bone density in adults with classic CAH.
  phenotype_term:
    preferred_term: Osteoporosis
    term:
      id: HP:0000939
      label: Osteoporosis
  evidence:
  - reference: PMID:36857009
    reference_title: "Long-term cardiometabolic morbidity in young adults with classic 21-hydroxylase deficiency congenital adrenal hyperplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Of 73, the patients who were treated for osteoporosis/osteopaenia,
      hyperlipidaemia, type 2 diabetes/hyperinsulinaemia, hypertension, CV
      disease, obesity were 43 (59%), 17 (23%), 16 (22%), 10 (14%), 8 (11), 3
      (4%) respectively.
    explanation: >-
      Directly reports osteoporosis/osteopaenia treatment among adults with
      classic 21-hydroxylase deficiency CAH treated for comorbidities.
- category: Growth
  name: Short Stature
  description: >-
    Severe early-diagnosed CAH can be associated with short adult stature,
    reflecting chronic androgen excess, accelerated maturation, and treatment
    balance.
  phenotype_term:
    preferred_term: Short stature
    term:
      id: HP:0004322
      label: Short stature
  subtypes:
  - Classic 21-OHD
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The age at diagnosis can provide some information about underlying
      mutations, with those diagnosed at birth/early infancy more likely to have
      severe enzymatic defects, which may include adrenal insufficiency, sexual
      development disorders, short stature in adulthood, hirsutism, and a higher
      risk for metabolic syndrome and infertility.
    explanation: Directly identifies short stature in adulthood among severe CAH manifestations.
- category: Reproductive
  name: Testicular Adrenal Rest Tumors
  description: >-
    Testicular adrenal rest tumors are an important male reproductive
    manifestation of classic CAH and can contribute to fertility impairment;
    no specific TART HPO term was verified locally, so this phenotype is left
    unbound rather than mapped to a broad parent term.
  subtypes:
  - Classic 21-OHD
  - Salt-Wasting 21-OHD
  - Simple-Virilizing 21-OHD
  evidence:
  - reference: PMID:40921717
    reference_title: "Longitudinal Characterization and Sonographic Staging of Testicular Adrenal Rest Tumors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Testicular adrenal rest tumors (TART) frequently develop and are the most
      common cause of male infertility in classic congenital adrenal hyperplasia
      (CAH).
    explanation: >-
      Directly identifies TART as a frequent manifestation in classic CAH and
      links it to male infertility.
- category: Metabolic
  name: Type 2 Diabetes or Hyperinsulinemia
  description: >-
    Adults with classic 21-hydroxylase deficiency CAH require surveillance for
    abnormal glucose homeostasis, including treated type 2 diabetes or
    hyperinsulinemia.
  phenotype_term:
    preferred_term: Type II diabetes mellitus
    term:
      id: HP:0005978
      label: Type II diabetes mellitus
  evidence:
  - reference: PMID:36857009
    reference_title: "Long-term cardiometabolic morbidity in young adults with classic 21-hydroxylase deficiency congenital adrenal hyperplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Of 73, the patients who were treated for osteoporosis/osteopaenia,
      hyperlipidaemia, type 2 diabetes/hyperinsulinaemia, hypertension, CV
      disease, obesity were 43 (59%), 17 (23%), 16 (22%), 10 (14%), 8 (11), 3
      (4%) respectively.
    explanation: >-
      Directly reports treated type 2 diabetes/hyperinsulinemia among adult CAH
      comorbidity cases.
biochemical:
- name: Elevated 17-hydroxyprogesterone
  notes: >-
    21-hydroxylase deficiency causes accumulation of steroid precursors before
    the enzymatic block, including 17-hydroxyprogesterone. 17-OHP is the analyte
    used for population newborn screening for CAH.
  loinc_term:
    id: LOINC:53340-6
    label: 17-Hydroxyprogesterone [Moles/volume] in DBS
  evidence:
  - reference: PMID:31984156
    reference_title: "Newborn Screening for Congenital Hypothyroidism, Congenital Adrenal Hyperplasia, and Glucose-6-Phosphate Dehydrogenase Deficiency for Improving Health Care in India."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      From January 2008 through December 2017, 13,376 newborns were screened for
      congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), and
      glucose-6-phosphate dehydrogenase (G6PD) deficiency at Sir Ganga Ram
      Hospital, India, by measuring G6PD activity, thyroid-stimulating hormone,
      and 17-hydroxyprogesterone on dried blood specimens.
    explanation: >-
      Human population screening evidence that 17-hydroxyprogesterone is the
      biochemical marker measured to detect CAH. Added because this marker
      previously rested solely on a zebrafish model, contrary to the rule that
      model-organism evidence should not be the only support for a human finding.
  - reference: PMID:28938470
    reference_title: "Genetic Disruption of 21-Hydroxylase in Zebrafish Causes Interrenal Hyperplasia."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Furthermore, Cyp21a2-deficient larvae had a typical steroid profile, with
      reduced concentrations of cortisol and increased concentrations of
      17-hydroxyprogesterone and 21-deoxycortisol.
    explanation: >-
      The zebrafish 21OHD model recapitulates the expected steroid precursor
      accumulation pattern.
- name: Reduced Cortisol
  notes: >-
    Reduced cortisol synthesis is the core biochemical abnormality linking CAH
    enzyme deficiency to adrenal insufficiency and ACTH-driven adrenal
    stimulation.
  evidence:
  - reference: PMID:37176569
    reference_title: "Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      CAH is characterized by the overproduction of androgen, along with
      variable degrees of cortisol and aldosterone deficiency.
    explanation: >-
      Human clinical evidence for cortisol deficiency in CAH. Added because this
      marker previously rested solely on a mouse model whose quoted readout is
      corticosterone, the rodent glucocorticoid, not cortisol.
  - reference: PMID:38791102
    reference_title: "A Humanized and Viable Animal Model for Congenital Adrenal Hyperplasia-CYP21A2-R484Q Mutant Mouse."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Mutant mice showed hyperplastic adrenals and exhibited reduced levels of
      corticosterone and 11-deoxycorticosterone and an increase in progesterone.
    explanation: >-
      The humanized mouse model reproduces blocked steroidogenesis with reduced
      glucocorticoid output and precursor accumulation, but the measured
      glucocorticoid is corticosterone (the rodent equivalent), not cortisol, so
      this is PARTIAL support for the human cortisol claim.
diagnosis:
- name: 17-hydroxyprogesterone biochemical testing
  description: >-
    Biochemical screening and confirmatory testing for 21-hydroxylase
    deficiency centers on 17-hydroxyprogesterone measurement, including newborn
    dried-blood-spot screening in many programs.
  measurements:
  - preferred_term: 17-hydroxyprogesterone, DBS
    term:
      id: LOINC:53340-6
      label: 17-Hydroxyprogesterone [Moles/volume] in DBS
  reference_ranges:
  - loinc_term:
      id: LOINC:53340-6
      label: 17-Hydroxyprogesterone [Moles/volume] in DBS
    unit: nmol/L
    population: >-
      newborn screening, North-Eastern Italy regional programme (DELFIA
      fluoroimmunoassay), term newborns
    notes: >-
      Source wording: "A preliminary cut-off level of > or = 30 nmol/l was set both
      for term and preterm newborns." The programme later set a separate, higher
      cut-off for preterm newborns only (next range), so 30 nmol/L is the level the
      source reports for term newborns. Screening cut-offs differ by programme and
      are stratified by maturity; this is the Italian programme's, not a universal
      threshold.
    interpretation_bands:
    - name: Screen negative
      upper_bound: 30
      unit: nmol/L
      abnormal_flag: NORMAL
    - name: Screen positive
      lower_bound: 30
      unit: nmol/L
      abnormal_flag: HIGH
      interpretation: >-
        17-OHP at or above the programme cut-off in a term newborn is a presumptive
        positive screen and triggers recall and confirmatory serum testing.
    evidence:
    - reference: PMID:15818055
      reference_title: "Neonatal screening for congenital adrenal hyperplasia in North-Eastern Italy: a report three years into the program."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "A preliminary cut-off level of > or = 30 nmol/l was set both for term and preterm newborns."
      explanation: >-
        States the dried-blood-spot 17-OHP cut-off applied to term newborns by the
        North-Eastern Italy programme.
  - loinc_term:
      id: LOINC:53340-6
      label: 17-Hydroxyprogesterone [Moles/volume] in DBS
    unit: nmol/L
    population: >-
      newborn screening, North-Eastern Italy regional programme (DELFIA
      fluoroimmunoassay), preterm newborns (gestational-age-related cut-off)
    notes: >-
      Source wording: "We chose a new cut-off value of 50 nmol/l for preterm newborns
      only". The source reports that under the single 30 nmol/L cut-off most recalled
      babies were preterm or low-birth-weight, and that the gestational-age-related
      cut-off reduced false-positive recalls among preterm babies.
    interpretation_bands:
    - name: Screen negative
      upper_bound: 50
      unit: nmol/L
      abnormal_flag: NORMAL
    - name: Screen positive
      lower_bound: 50
      unit: nmol/L
      abnormal_flag: HIGH
      interpretation: >-
        17-OHP at or above the preterm cut-off is a presumptive positive screen in a
        preterm newborn.
    evidence:
    - reference: PMID:15818055
      reference_title: "Neonatal screening for congenital adrenal hyperplasia in North-Eastern Italy: a report three years into the program."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "We chose a new cut-off value of 50 nmol/l for preterm newborns only and, after 4 months, the recall rate was reduced to 0.83% for these infants and to 1.83% for low-birth-weight infants."
      explanation: >-
        States the gestational-age-related preterm cut-off adopted by the same
        programme.
  - loinc_term:
      id: LOINC:53340-6
      label: 17-Hydroxyprogesterone [Moles/volume] in DBS
    unit: nmol/L
    population: >-
      newborn screening, Cuba national programme (17OHP Neonatal UMELISA), samples
      collected on about day 5 of life
    notes: >-
      Source wording: "Confirmatory test was performed to those neonates with 17OHP
      values above 55 nmol/l." The source says "above", so a result exactly at 55
      nmol/L was not recalled; the half-open band convention places 55 in the
      positive band, a one-point discrepancy noted here rather than hidden. The
      programme did not stratify by birth weight or gestational age during the
      reported period.
    interpretation_bands:
    - name: Screen negative
      upper_bound: 55
      unit: nmol/L
      abnormal_flag: NORMAL
    - name: Screen positive
      lower_bound: 55
      unit: nmol/L
      abnormal_flag: HIGH
      interpretation: >-
        17-OHP above the Cuban cut-off led to recall for confirmatory testing.
    evidence:
    - reference: PMID:23481450
      reference_title: "Newborn screening for congenital adrenal hyperplasia in Cuba: six years of experience."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Confirmatory test was performed to those neonates with 17OHP values above 55 nmol/l."
      explanation: >-
        States the recall cut-off used by the Cuban national newborn screening
        programme.
  notes: >-
    LOINC codes and labels were read from the Monarch KG and seeded into
    cache/loinc/terms.csv by scripts/seed_loinc_cache.sh. The molar DBS code is bound
    because every cited cut-off is in nmol/L; LOINC also carries a mass-concentration
    DBS code (17-Hydroxyprogesterone [Mass/volume] in DBS, LOINC:38473-5) for
    programmes reporting ng/mL, which is not bound here because no ng/mL cut-off is
    cited.
  evidence:
  - reference: PMID:31984156
    reference_title: "Newborn Screening for Congenital Hypothyroidism, Congenital Adrenal Hyperplasia, and Glucose-6-Phosphate Dehydrogenase Deficiency for Improving Health Care in India."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      From January 2008 through December 2017, 13,376 newborns were screened for
      congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), and
      glucose-6-phosphate dehydrogenase (G6PD) deficiency at Sir Ganga Ram
      Hospital, India, by measuring G6PD activity, thyroid-stimulating hormone,
      and 17-hydroxyprogesterone on dried blood specimens.
    explanation: >-
      Demonstrates population newborn screening for CAH using dried-blood-spot
      17-hydroxyprogesterone.
  - reference: PMID:23481450
    reference_title: "Newborn screening for congenital adrenal hyperplasia in Cuba: six years of experience."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Since 2005, a newborn screening program for congenital adrenal hyperplasia (CAH) by measuring 17-alpha-hydroxyprogesterone (17OHP) in dried blood spots was introduced in Cuba."
    explanation: >-
      A national programme measuring dried-blood-spot 17-OHP as the CAH screening
      analyte.
  - reference: PMID:15818055
    reference_title: "Neonatal screening for congenital adrenal hyperplasia in North-Eastern Italy: a report three years into the program."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Since September 2001, blood samples from neonates born in North-Eastern Italy have been screened with a fluoroimmunoassay method for 17-OHP determination (DELFIA)."
    explanation: >-
      Names the assay behind the Italian programme's cut-offs recorded above.
- name: CYP21A2 genetic testing
  description: >-
    Molecular testing for CYP21A2 supports diagnosis, genotype-phenotype
    interpretation, family counseling, and recurrence-risk assessment.
  diagnosis_term:
    preferred_term: genetic testing
    term:
      id: NCIT:C15709
      label: Genetic Testing
  evidence:
  - reference: PMID:39911519
    reference_title: "Genetics in Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency and Clinical Implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      However, a genetic test to determine the CYP21A2 variants is central in
      confirming the 21OHD diagnosis, genetic counseling, to predict the
      phenotype and possibly other aspects of CAH such as long-term outcomes.
    explanation: >-
      The paper's own concluding assessment of what CYP21A2 testing is for, and
      it covers the uses this entry claims: confirming the diagnosis, predicting
      the phenotype, and genetic counselling. The sentence previously quoted here
      said only that molecular diagnosis is complex and involves ongoing
      challenges, which supported none of them.
treatments:
- name: Glucocorticoid replacement
  description: >-
    Glucocorticoid therapy replaces deficient cortisol and suppresses excess
    ACTH-driven adrenal androgen production; treatment must balance androgen
    control against glucocorticoid-related complications.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: therapeutic hydrocortisone
      term:
        id: NCIT:C555
        label: Therapeutic Hydrocortisone
  target_mechanisms:
  - target: Cortisol and Aldosterone Deficiency
    treatment_effect: RESTORES
    description: Glucocorticoid replacement restores deficient cortisol action.
  - target: ACTH-Driven Adrenal Hyperplasia and Androgen Excess
    treatment_effect: INHIBITS
    description: >-
      Adequate glucocorticoid replacement suppresses ACTH-driven adrenal
      androgen overproduction.
  evidence:
  - reference: PMID:38828955
    reference_title: "Phase 3 Trial of Crinecerfont in Adult Congenital Adrenal Hyperplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Adrenal insufficiency in patients with classic 21-hydroxylase deficiency
      congenital adrenal hyperplasia (CAH) is treated with glucocorticoid
      replacement therapy.
    explanation: Directly supports glucocorticoid replacement as standard CAH therapy.
- name: Mineralocorticoid replacement
  description: >-
    Fludrocortisone replaces mineralocorticoid activity in salt-wasting CAH and
    is used with glucocorticoids in many adults with classic disease.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: fludrocortisone
      term:
        id: NCIT:C71629
        label: Fludrocortisone
  target_mechanisms:
  - target: Cortisol and Aldosterone Deficiency
    treatment_effect: RESTORES
    description: Fludrocortisone replaces deficient mineralocorticoid action.
  target_phenotypes:
  - preferred_term: hyponatremia
    term:
      id: HP:0002902
      label: Hyponatremia
  evidence:
  - reference: PMID:36857009
    reference_title: "Long-term cardiometabolic morbidity in young adults with classic 21-hydroxylase deficiency congenital adrenal hyperplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Of these, 126 (52%) were females and 174 (71%) received fludrocortisone in
      addition to glucocorticoids.
    explanation: >-
      Documents frequent combined fludrocortisone and glucocorticoid treatment
      in adults with classic 21-hydroxylase deficiency CAH.
- name: Crinecerfont adjunct therapy
  description: >-
    Crinecerfont is an oral corticotropin-releasing factor type 1 receptor
    antagonist that reduces ACTH-driven androgen excess and enables lower
    glucocorticoid doses in classic CAH.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: crinecerfont
      term:
        id: NCIT:C174708
        label: Crinecerfont
  target_mechanisms:
  - target: ACTH-Driven Adrenal Hyperplasia and Androgen Excess
    treatment_effect: INHIBITS
    description: >-
      CRF1 receptor antagonism lowers ACTH drive and helps reduce adrenal
      androgen excess.
  evidence:
  - reference: PMID:38828955
    reference_title: "Phase 3 Trial of Crinecerfont in Adult Congenital Adrenal Hyperplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Crinecerfont, an oral corticotropin-releasing factor type 1 receptor
      antagonist, lowered androstenedione levels in phase 2 trials involving
      patients with CAH.
    explanation: >-
      Identifies the mechanism and prior androgen-lowering evidence for
      crinecerfont in CAH.
  - reference: PMID:38828955
    reference_title: "Phase 3 Trial of Crinecerfont in Adult Congenital Adrenal Hyperplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Among patients with CAH, the use of crinecerfont resulted in a greater
      decrease from baseline in the mean daily glucocorticoid dose, including a
      reduction to the physiologic range, than placebo following evaluation of
      adrenal androgen levels.
    explanation: >-
      Phase 3 evidence supports a glucocorticoid-sparing benefit while monitoring
      adrenal androgen control.
- name: CYP21A2 gene therapy
  description: >-
    AAV-mediated CYP21A2 gene therapy is investigational and is designed to
    restore adrenal steroidogenesis upstream of hormone deficiency and androgen
    shunting.
  therapeutic_modality: GENE_THERAPY
  treatment_term:
    preferred_term: gene therapy
    term:
      id: NCIT:C15238
      label: Gene Therapy
  target_mechanisms:
  - target: CYP21A2 21-Hydroxylase Deficiency
    treatment_effect: RESTORES
    description: >-
      CYP21A2 delivery aims to restore the deficient steroidogenic enzyme step.
  evidence:
  - reference: PMID:36982440
    reference_title: "Models of Congenital Adrenal Hyperplasia for Gene Therapies Testing."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Congenital adrenal hyperplasia (CAH) is an example of such a potentially
      treatable monogenic disease.
    explanation: >-
      Supports gene therapy as a plausible investigational strategy while not
      establishing clinical efficacy.
clinical_trials:
- name: NCT04490915
  phase: PHASE_III
  status: ACTIVE_NOT_RECRUITING
  description: >-
    Phase 3 trial of crinecerfont versus placebo in adults with classic CAH due
    to 21-hydroxylase deficiency, followed by open-label treatment.
  evidence:
  - reference: clinicaltrials:NCT04490915
    reference_title: "A Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Safety and Efficacy of Crinecerfont (NBI-74788) in Adult Subjects With Classic Congenital Adrenal Hyperplasia, Followed by Open-Label Treatment"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This is a Phase 3 study to evaluate the efficacy, safety, and tolerability
      of crinecerfont versus placebo administered for 24 weeks in approximately
      165 adult participants with classic CAH due to 21-hydroxylase deficiency.
    explanation: >-
      The trial record directly describes the crinecerfont CAH phase 3 study.
- name: NCT04783181
  phase: PHASE_I
  status: ACTIVE_NOT_RECRUITING
  description: >-
    Phase 1/2 first-in-human AAV5-based BBP-631 CYP21A2 gene therapy study for
    adults with classic CAH.
  evidence:
  - reference: clinicaltrials:NCT04783181
    reference_title: "A Phase 1/2, First-in-Human, Open-Label, Dose-Escalation Study of the Safety and Efficacy of Gene Therapy for Congenital Adrenal Hyperplasia Through Administration of an Adeno-Associated Virus (AAV) Serotype 5-Based Recombinant Vector Encoding the Human CYP21A2 Gene"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This study is designed to evaluate the safety, tolerability, and efficacy
      of AAV5 based BBP-631 in adult participants diagnosed with classic
      congenital adrenal hyperplasia.
    explanation: >-
      The trial record directly describes an AAV5 BBP-631 gene therapy study in
      classic CAH.
datasets:
- accession: dbgap:phs001317
  title: Long-Term Outcome in Offspring and Mothers of Dexamethasone-Treated Pregnancies at Risk for Classical Congenital Adrenal Hyperplasia Owing to 21-Hydroxylase Deficiency
  description: '  Summary    The purpose of this study is to perform the first long-term follow up study both of adolescents and young adults with a history of prenatal treatment with dexamethasone and of their mothers and to test for adverse medical or behavioral side effects. The emphasis will be on the outcome of this prenatal treatment in those fetuses who are not affected with steroid 21-hydroxylase deficiency (21OHD) form of congenital adrenal hyperplasia (CAH) and are either heterozygotes or homozygote-unaffected.   Prenatal treatment of 46,XX fetuses with 21OHD (via administration of '
  notes: Located via OmicsDI, which aggregates across omics repositories; this record comes from dbgap. Only repositories with no other discovery route in this project and with a working accession resolver are curated from OmicsDI -- GEO, ArrayExpress, PRIDE, MetaboLights and EGA hits are excluded as duplicates of dedicated passes. Matched because the disease is named in the dataset's own title ("Congenital Adrenal Hyperplasia"). Retrieved 2026-08-02.

📚

References & Deep Research

References

1

PMID:20301350

21-Hydroxylase-Deficient Congenital Adrenal Hyperplasia.

No top-level findings curated for this source.

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (2)

Prune empty Falcon bibliography from references: block · 2026-08-23T16:25:02Z · View source

Removed the top-level references: block (18 entries), all carrying findings: [] with no extracted claims, snippets, or supporting_text -- pure deep-research (Falcon) bibliography noise per issue #6980 section 3's own description that CAH has the same pattern as MEN2 (18 DOIs, findings: [] throughout). Verified none of the 18 DOIs are cited elsewhere in the file (each appeared exactly once, only inside this now-removed block), so no evidence item lost its reference. Did not touch Multiple_Endocrine_Neoplasia_Type_2.yaml's parallel references: block, which mixes empty and populated findings and needs a content-by-content judgment call (title-vs-finding per CLAUDE.md section 6) rather than a mechanical delete; left for a follow-up. Validated with just validate, count-verified-snippets (39/39), check-duplicate-keys, check-folded-hyphens, check-snippet-length, check-title-snippets, check-environmental-evidence, and the CAH-scoped pytest suite (16/16).

Review: Congenital Adrenal Hyperplasia (Changes required) · 2026-05-31T03:02:20Z · View source

GitHub review issue: https://github.com/monarch-initiative/dismech/issues/3615 Issue state: OPEN Issue created: 2026-05-31T03:02:20Z Issue updated: 2026-05-31T03:02:20Z Issue closed: not closed Review decision: Changes required Labels: review ## Completed curation review - Disease: **Congenital Adrenal Hyperplasia** - Entry: `kb/disorders/Congenital_Adrenal_Hyperplasia.yaml` - Selection basis: #146 of the least-recently edited Mendelian entries - Review decision: **Changes required** - Validation stance: assumes schema, ontology-term, and reference validation pass; this is a biological/clinical/content review. ## Findings 1. Actionable baseline check: a `diagnosis` section exists, but no top-level GeneReviews tag was detected in the YAML. For this Mendelian entry, confirm whether a GeneReviews article exists and either add/tag it or record why no GeneReviews baseline applies. 2. Research-artifact consumption: matching deep-research artifact(s) exist and should be treated as first-class review inputs. Compare the YAML against the artifact(s), especially for central mechanisms, subtype-specific features, treatments/trials, and diagnostic/surveillance details rather than only schema-valid content. 3. Subtype completeness: `has_subtypes` is present (Classic 21-OHD, Salt-Wasting 21-OHD, Simple-Virilizing 21-OHD, Nonclassic 21-OHD). Verify that subtype-specific phenotypes, mechanisms, treatments, diagnosis, and genetic contexts are attached to the correct subtype rather than left as broad disease-level claims. 4. Pathophysiology review: the main modeled mechanisms include CYP21A2 21-Hydroxylase Deficiency, CYP11B1 11-Beta-Hydroxylase Deficiency, CYP17A1 17-Hydroxylase/17,20-Lyase Deficiency, Cortisol and Aldosterone Deficiency. Check that each is an atomic event with direct evidence and that downstream edges do not encode multi-step chains or unsupported causal leaps from gene/product defect to organ-level phenotype. 5. Treatment/trial alignment: both `treatments` and `clinical_trials` are present. Verify that trial interventions, phases/statuses, target phenotypes, and treatment entries agree, and distinguish approved/standard care from investigational or case-report therapy. 6. Evidence/reference check: top references include PMID:39911519, PMID:28228528, PMID:34524979, PMID:37176569. Spot-check that snippets directly support the specific claim, frequency, and evidence_source classification, especially where the same PMID is reused across phenotype, mechanism, and treatment assertions. ## Content-Completeness Checklist - Phenotype coverage: phenotype list needs manual review for disease-defining features. - Subtype completeness: subtypes present; verify subtype-specific anchoring. - Pathophysiology depth: mechanisms present but require atomicity/evidence review. - Treatments and trials: present; verify standard-vs-investigational scope. - Genetics: genetic section present; verify inheritance, variant classes, and genotype-phenotype claims. - Biomarkers/diagnostics: diagnosis present but should be checked against baseline sources. - References/research consumption: compare the YAML against listed sources and local research artifacts; do not treat retrieval-heavy papers as issues unless they are disease-specific and directly modelable. ## Suggested Remediation Resolve the blocking diagnostic/baseline gaps first, then tighten subtype-specific claims, pathophysiology atomicity, treatment/trial scope, and evidence-to-claim alignment. Keep deterministic schema/term/reference validation separate from this biological review. ## Sources Used - Local research artifact: `research/Congenital_Adrenal_Hyperplasia-deep-research-falcon.md` - PMID:39911519: https://pubmed.ncbi.nlm.nih.gov/39911519/ - PMID:28228528: https://pubmed.ncbi.nlm.nih.gov/28228528/ - PMID:34524979: https://pubmed.ncbi.nlm.nih.gov/34524979/ - PMID:37176569: https://pubmed.ncbi.nlm.nih.gov/37176569/ No YAML files or `references_cache/*.md` files were edited for this review.

Falcon ▸

Disease Characteristics Research Template

Edison Scientific Literature 51 citations 2026-05-07T09:20:03.345763

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

Disease Name: Congenital Adrenal Hyperplasia
MONDO ID: (if available)
Category: Mendelian

Research Objectives

Please provide a comprehensive research report on Congenital Adrenal Hyperplasia covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

What is the disease? Provide a concise overview.
What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
What are the common synonyms and alternative names?
Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
Risk Factors:

Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases
Genetic risk factors (causal variants, susceptibility loci, modifier genes)
Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
Protective Factors:

Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases
Genetic protective factors (protective variants, modifier alleles)
Environmental protective factors (diet, lifestyle, exposures that reduce risk)
Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene
Pathogenic Variants:
Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
Variant type/class (missense, frameshift, nonsense, splice-site, structural)
Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
Functional consequences (loss of function, gain of function, dominant negative)
Modifier Genes: Genes that modify disease severity or expression
Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth
Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases
Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

Search first: CDC databases, WHO, PubMed, NHANES
Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc
Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

Search first: Gene Ontology (GO), Reactome, KEGG, PubMed
Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold
Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA
Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

Search first: ImmPort, Immunome Database, IEDB, Gene Ontology
Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

Search first: PubMed, Gene Ontology, Reactome
Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

Search first: BRENDA, UniProt, KEGG, OMIM, PubMed
Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth
Molecular Profiling (if available):
Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
Advanced Technologies (if applicable):
Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

Organ Level:
Primary organs directly affected
Secondary organ involvement (complications, secondary effects)
Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT
Tissue and Cell Level:
Specific tissue types affected (epithelial, connective, muscle, nervous)
Specific cell populations targeted (with Cell Ontology terms)

Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB
Subcellular Level:
Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas
Localization:
Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

Onset:
Typical age of onset (congenital, pediatric, adult, geriatric)
Onset pattern (acute, subacute, chronic, insidious)

Search first: OMIM, Orphanet, HPO, PubMed
Progression:
Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
Progression rate (rapid, slow, variable)
Disease course pattern (episodic, relapsing-remitting, progressive, stable)
Disease duration (self-limited, chronic lifelong)

Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM
Patterns:
Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

Epidemiology:
Prevalence (cases per 100,000 at given time)
Incidence (new cases per 100,000 per year)

Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries
For Genetic Etiology:
Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
Population Demographics:
Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
Geographic distribution of specific variants
Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

Clinical Tests:
Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
Genetic Testing:

Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen
Overview of recommended genetic testing approach
Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
FISH > Search first: ClinVar, cytogenetics databases, PubMed
Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
Omics-Based Diagnostics (if applicable):
RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
Clinical Criteria:
Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
Screening:
Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

Survival and Mortality:
Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
Mortality rate > Search first: CDC, WHO, GBD, national mortality databases
Disease-specific mortality (deaths directly attributable to disease) > Search first: Disease registries, CDC Wonder, GBD, PubMed
Morbidity and Function:
Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
Disability outcomes (long-term functional impairments) > Search first: ICF (International Classification of Functioning), disability registries
Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
Disease Course:
Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
Recovery potential (likelihood and extent of recovery, with vs without treatment) > Search first: Natural history studies, rehabilitation databases, PubMed
Prediction:
Prognostic factors (age, disease severity, biomarkers, treatment response) > Search first: Prognostic models databases, clinical calculators, PubMed
Prognostic biomarkers (molecular markers predicting disease course) > Search first: FDA Biomarker database, PubMed, cancer prognostic databases

12. Treatment

Pharmacotherapy:
Pharmacological treatments (drug names, drug classes, mechanisms of action) > Search first: DrugBank, RxNorm, ATC classification, DailyMed, FDA databases
Pharmacogenomics (how genetic variants affect drug metabolism, efficacy, toxicity) > Search first: PharmGKB, CPIC (Clinical Pharmacogenetics), FDA Table of PGx Biomarkers
Advanced Therapeutics:
Gene therapy (viral vectors, CRISPR, gene replacement, gene editing) > Search first: ClinicalTrials.gov, FDA gene therapy database, ASGCT resources
Cell therapy (stem cell transplant, CAR-T, cellular therapeutics) > Search first: ClinicalTrials.gov, FDA cell therapy database, FACT standards
RNA-based therapies (ASOs, siRNA, mRNA therapies) > Search first: ClinicalTrials.gov, FDA approvals, PubMed
Targeted therapies (treatments directed at specific molecular targets) > Search first: My Cancer Genome, OncoKB, ClinicalTrials.gov, FDA approvals
Immunotherapies (checkpoint inhibitors, monoclonal antibodies) > Search first: Cancer Immunotherapy Database, FDA approvals, ClinicalTrials.gov
Surgical and Interventional:
Surgical interventions (types of surgery, timing, outcomes) > Search first: CPT codes, surgical registries, clinical guidelines, PubMed
Supportive and Rehabilitative:
Supportive care (symptom management, pain control, nutrition) > Search first: Clinical guidelines, Cochrane Library, PubMed
Rehabilitation (physical therapy, occupational therapy, speech therapy) > Search first: Rehabilitation medicine databases, clinical guidelines, PubMed
Experimental:
Experimental treatments in clinical trials (with NCT identifiers if available) > Search first: ClinicalTrials.gov, EU Clinical Trials Register, WHO ICTRP
Treatment Outcomes:
Treatment response rates > Search first: Clinical trial databases, FDA reviews, systematic reviews, PubMed
Side effects and adverse events > Search first: FDA Adverse Event Reporting System (FAERS), MedWatch, PubMed
Treatment Strategy:
Treatment algorithms (clinical pathways, decision trees) > Search first: Clinical practice guidelines, NCCN Guidelines, UpToDate
Combination therapies > Search first: ClinicalTrials.gov, treatment guidelines, PubMed
Personalized medicine approaches (genotype-guided treatment) > Search first: My Cancer Genome, CIViC, PharmGKB, precision medicine databases

For each treatment, suggest MAXO (Medical Action Ontology) terms where applicable.

13. Prevention

Prevention Levels:
Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
Immunization: Vaccine strategies (if applicable)

Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database
Screening and Early Detection:
Screening programs (population-based: newborn screening, cancer screening) > Search first: CDC screening programs, USPSTF, cancer screening databases
Genetic screening (carrier screening, preimplantation genetic diagnosis, prenatal testing) > Search first: ACMG recommendations, ACOG guidelines, GTR
Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
Behavioral Interventions: Lifestyle modifications to reduce risk

Search first: CDC, WHO, behavioral intervention databases, Cochrane Library
Counseling: Genetic counseling (risk assessment, family planning guidance)

Search first: NSGC resources, ACMG guidelines, GeneReviews
Public Health:
Public health interventions (sanitation, vector control, health education) > Search first: CDC, WHO, public health databases, PubMed
Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
Prophylaxis: Preventive medications or procedures

Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

Taxonomy: Species affected (with NCBI Taxon identifiers)

Search first: NCBI Taxonomy
Breed: Specific breeds affected (with VBO identifiers if applicable)

Search first: VBO (Vertebrate Breed Ontology)
Gene: Orthologous genes in other species (with NCBI Gene IDs)

Search first: NCBI Gene
Natural Disease:
Naturally occurring disease in other species (companion animals, wildlife) > Search first: OMIA (Online Mendelian Inheritance in Animals), VetCompass, PubMed
Veterinary relevance and importance in animal health > Search first: OMIA, veterinary databases, PubMed
Comparative Biology:
Comparative pathology (similarities and differences across species) > Search first: OMIA, comparative pathology databases, PubMed
Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
Transmission (if applicable):
Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

Model Types:
Model organism type (mammalian, invertebrate, cellular, in vitro) > Search first: Alliance of Genome Resources, model organism databases
Specific model systems (mouse, rat, zebrafish, Drosophila, C. elegans, yeast, cell lines, organoids, iPSCs) > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, SGD, ATCC, Cellosaurus
Induced models (drug treatment, surgical intervention, environmental manipulation) > Search first: MGI, model organism databases, PubMed
Genetic Models:
Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
Model Characteristics:
Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
Applications:
Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
Resources:
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Citation Requirements

Cite primary literature (PMID preferred) for all mechanistic and clinical claims
Prioritize recent reviews and landmark papers
Include direct quotes from abstracts where possible to support key statements
Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, MAXO, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (MAXO terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

Congenital Adrenal Hyperplasia (CAH) — Disease Characteristics Research Report (Mendelian)

Target disease and scope

Congenital adrenal hyperplasia (CAH) is a group of inherited disorders of adrenal steroidogenesis; ~95–99% of CAH is due to 21-hydroxylase deficiency (21-OHD) caused by pathogenic variants in CYP21A2, leading to cortisol deficiency with variable aldosterone deficiency and androgen excess. (concolino2025geneticsincongenital pages 1-2, gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 3-6)

This report emphasizes 21-OHD CAH (classic salt-wasting/simple virilizing and nonclassic) while also summarizing rarer enzymatic etiologies.

1. Disease information

1.1 Concise overview

CAH (21-OHD) results from reduced 21-hydroxylase activity in the adrenal cortex. The defect decreases cortisol synthesis; reduced cortisol negative feedback increases ACTH drive, promoting adrenal hyperplasia and shunting steroid precursors into androgen pathways, causing prenatal virilization in some 46,XX fetuses and postnatal hyperandrogenism in both sexes. (concolino2025geneticsincongenital pages 1-2, uslar2023clinicalupdateon pages 3-6)

1.2 Key identifiers (available in retrieved evidence)

MONDO: MONDO_0018479 (“congenital adrenal hyperplasia”) via Open Targets disease record. (OpenTargets Search: Congenital adrenal hyperplasia)
ICD-10-CM: E25.0 used for administrative/claims identification of CAH in US datasets and Swedish national registers. (harasymiw2020attentiondeficithyperactivitydisorderamong pages 3-3, falhammar2019increasedriskof pages 2-3)

Not found in retrieved full texts for this run (thus not evidence-backed here): OMIM disease entry numbers, Orphanet ORPHA codes, MeSH headings, ICD-11 codes.

1.3 Common synonyms / alternative names

“Adrenogenital syndrome” appears as a closely related disease term in Open Targets and in ICD coding contexts. (OpenTargets Search: Congenital adrenal hyperplasia, harasymiw2020attentiondeficithyperactivitydisorderamong pages 3-3)

1.4 Evidence provenance type

This report integrates: - Aggregated disease-level resources (Open Targets MONDO mapping; reviews). (OpenTargets Search: Congenital adrenal hyperplasia, uslar2023clinicalupdateon pages 3-6, concolino2025geneticsincongenital pages 1-2) - Human clinical studies/registries/claims (NEJM phase 3 trial; national cohort; multicenter surveys; newborn screening cohort). (auchus2024phase3trial pages 1-3, falhammar2019increasedriskof pages 1-2, righi2023longtermcardiometabolicmorbidity pages 1-2, verma2020newbornscreeningfor pages 1-2) - Model organism studies/reviews (zebrafish, mouse; gene-therapy model reviews). (eachus2017geneticdisruptionof pages 1-2, thirumalasetty2024ahumanizedand pages 1-2, glazova2023modelsofcongenital pages 2-4)

2. Etiology

2.1 Disease causal factors

Primary cause (genetic): autosomal recessive pathogenic variation in steroidogenic enzymes, most commonly CYP21A2 (21-hydroxylase). (concolino2025geneticsincongenital pages 1-2, gunes2025clinicalbiochemicaland pages 1-2)

Genetic architecture of CYP21A2 locus: The 2023 multidisciplinary review summarizes that CYP21A2 sits in the HLA region and that pathogenic variants frequently arise from recombination with the pseudogene (microconversions ~75%, unequal crossing-over 20–25%, de novo 1–2%), with >200 known variants but ~10 accounting for ~90% of cases. (uslar2023clinicalupdateon pages 6-7)

Rare CAH etiologies: include 11β-hydroxylase deficiency (CYP11B1), 3β-HSD deficiency (HSD3B2), 17-hydroxylase deficiency (CYP17A1), and lipoid CAH (STAR). (OpenTargets Search: Congenital adrenal hyperplasia)

2.2 Risk factors

Inheritance pattern: CAH due to 21-OHD is autosomal recessive. (concolino2025geneticsincongenital pages 1-2, gunes2025clinicalbiochemicaland pages 1-2)
Carrier frequency (severe alleles): one multidisciplinary program review reports ~1 in 60 (2%) prevalence of severe allelic variants in the population. (uslar2023clinicalupdateon pages 9-10)

2.3 Protective factors

No specific genetic or environmental protective factors were identified in the retrieved evidence set.

2.4 Gene–environment interactions

The retrieved evidence emphasizes genetic causation and treatment-related complications rather than clear gene–environment interaction effects.

3. Phenotypes (clinical spectrum)

3.1 Current clinical classification

A widely used clinical framework divides 21-OHD into: - Classic salt-wasting (SW): typically 65–75% of classic cases, residual activity <1%, neonatal adrenal insufficiency/salt-wasting crisis and 46,XX virilization. (uslar2023clinicalupdateon pages 3-6) - Classic simple virilizing (SV): 25–35% of classic, residual activity ~1–2%, hyperandrogenism with less/minimal mineralocorticoid deficiency. (uslar2023clinicalupdateon pages 3-6) - Nonclassic (NCCAH): residual activity ~20–50%, later-onset hyperandrogenism (acne, hirsutism, oligomenorrhea/infertility), commonly considered in PCOS differential diagnosis. (uslar2023clinicalupdateon pages 3-6)

A 2025 pediatric endocrine review also emphasizes that phenotype likely represents a continuum rather than discrete bins. (gunes2025clinicalbiochemicaland pages 1-2)

3.2 Phenotype list with ontology suggestions

Key phenotype annotations (including quantitative frequencies where available) are summarized in the table artifact below.

Phenotype (plain)	Phenotype type	Typical onset	Frequency / notes	Suggested HPO term(s)	Supporting citations
Salt-wasting crisis with hyponatremia, hyperkalemia, hypovolemia/shock	Symptom/sign/laboratory abnormality	Neonatal / early infancy	Classic salt-wasting CAH accounts for 65–75% of classic cases; residual 21-hydroxylase activity typically <1%; neonatal crises may be life-threatening if unrecognized	Salt-wasting HP:0002013; Hyponatremia HP:0002902; Hyperkalemia HP:0002153; Shock HP:0001278	(uslar2023clinicalupdateon pages 3-6, gunes2025clinicalbiochemicaland pages 1-2, concolino2025geneticsincongenital pages 1-2)
Virilized / ambiguous external genitalia in 46,XX infants	Physical manifestation / sign	Prenatal, recognized at birth	Typical of classic CAH; females may show varying degrees of virilization (Prader 1–5) from fetal androgen excess	Ambiguous genitalia HP:0000062; Clitoromegaly HP:0000058; Abnormality of the labia HP:0000060	(uslar2023clinicalupdateon pages 3-6, abalı2025antenataldiagnosisand pages 1-2, concolino2025geneticsincongenital pages 1-2)
Precocious pubarche / premature pubic hair	Sign	Early childhood	Characteristic of simple virilizing classic CAH and can occur in NCCAH due to androgen excess	Precocious pubarche HP:0000878	(gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 3-6)
Accelerated linear growth	Sign	Childhood	Seen in classic CAH, especially simple virilizing disease; reflects chronic androgen excess	Accelerated growth HP:0001510	(gunes2025clinicalbiochemicaland pages 1-2)
Advanced bone age	Laboratory / imaging-associated abnormality	Childhood	Common in simple virilizing CAH and progressive androgen excess states	Advanced skeletal maturation HP:0002750	(gunes2025clinicalbiochemicaland pages 1-2)
Acne	Symptom / sign	Adolescence to adulthood; can occur earlier in NCCAH	Common hyperandrogenic presentation in nonclassic CAH	Acne HP:0001074	(gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 3-6)
Hirsutism	Sign	Adolescence to adulthood	Common in nonclassic CAH; part of late-onset hyperandrogenism spectrum	Hirsutism HP:0001007	(gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 9-10)
Menstrual irregularity / oligomenorrhea / amenorrhea	Symptom / sign	Adolescence to adulthood	Common in nonclassic CAH women; important differential with PCOS	Irregular menstruation HP:0000858; Oligomenorrhea HP:0000879; Amenorrhea HP:0000141	(gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 3-6)
Infertility / reduced fertility	Clinical outcome / symptom	Adolescence to adulthood	In untreated classic CAH, up to 90% of women may experience infertility; NCCAH infertility and miscarriage risk can improve with hydrocortisone, with conception rates reported close to 90% under treatment in cited review	Infertility HP:0000789; Female infertility HP:0008209	(uslar2023clinicalupdateon pages 9-10)
Testicular adrenal rest tumors (TARTs)	Physical manifestation / imaging finding	Childhood through adulthood	Prevalence reported as ~20% in children and 50–80% in adults; surveillance with testicular ultrasound from age 8 years every 2 years was recommended in one review	Testicular adrenal rest tumor HP:0034827; Abnormal testicular morphology HP:0000119	(uslar2023clinicalupdateon pages 9-10)
Obesity / increased adiposity	Comorbidity / sign	Childhood through adulthood	Common long-term comorbidity; in one adult cohort obesity screening occurred in 97% of centers; prevalence varied by country, e.g. 41% in UK cohort, and all obese patients in one surveyed cohort had salt-wasting CAH	Obesity HP:0001513; Increased body mass index HP:0001956	(righi2023longtermcardiometabolicmorbidity pages 4-5, righi2023longtermcardiometabolicmorbidity pages 2-3, righi2023longtermcardiometabolicmorbidity pages 1-2, zaric2025metabolicsyndromespectrum pages 1-2)
Hypertension / elevated systolic blood pressure	Comorbidity / sign	Childhood through adulthood	In adult cohort, 10/244 were treated for hypertension; pediatric review reported 58% systolic hypertension and 24% diastolic hypertension in one CCAH study, with loss of nocturnal dipping particularly in salt-wasting patients	Hypertension HP:0000822	(righi2023longtermcardiometabolicmorbidity pages 1-2, zaric2025metabolicsyndromespectrum pages 12-14)
Osteoporosis / osteopenia	Comorbidity / sign	Adulthood (can emerge earlier with chronic treatment exposure)	Most common treated comorbidity in one adult survey: 43/73 (59%) of treated comorbidity cases received therapy for osteoporosis/osteopenia; bone screening performed by 81% of centers, mainly DXA	Osteoporosis HP:0000939; Osteopenia HP:0000938	(righi2023longtermcardiometabolicmorbidity pages 4-5, righi2023longtermcardiometabolicmorbidity pages 2-3, righi2023longtermcardiometabolicmorbidity pages 1-2)
Type 2 diabetes / insulin resistance / abnormal glucose homeostasis	Comorbidity / laboratory abnormality	Childhood to adulthood	Adult cohort: 16/73 (22%) of treated comorbidity cases had type 2 diabetes/hyperinsulinaemia; pediatric review found insulin resistance frequently increased in classic CAH	Insulin resistance HP:0000855; Hyperinsulinemia HP:0003074; Type II diabetes mellitus HP:0005978	(righi2023longtermcardiometabolicmorbidity pages 1-2, zaric2025metabolicsyndromespectrum pages 1-2, zaric2025metabolicsyndromespectrum pages 12-14)
Autoimmune disorders increased risk	Comorbidity	Usually later childhood to adulthood	Swedish national cohort: autoimmune disorders in 7.4% of 21OHD patients vs 5.1% of controls; RR 1.47 (95% CI 1.13–1.91), with increased autoimmune endocrine and thyroid disease	Autoimmunity HP:0002960; Autoimmune thyroiditis HP:0002726	(falhammar2019increasedriskof pages 1-2)

Table: This table summarizes major clinical phenotypes and comorbidities across classic salt-wasting, simple virilizing, and nonclassic 21-hydroxylase deficiency CAH. It includes suggested HPO mappings and recent quantitative frequencies where available to support knowledge-base phenotype annotation.

Quality-of-life burdens are repeatedly linked to chronic androgen excess, adrenal crises, growth concerns, reproductive challenges, and long-term metabolic/bone outcomes, with the management goal framed as optimizing long-term health and daily functioning while avoiding glucocorticoid overtreatment. (uslar2023clinicalupdateon pages 3-6, harris2025congenitaladrenalhyperplasia pages 7-9)

4. Genetic / molecular information

4.1 Causal genes (human)

Primary genes supported in this evidence set: - CYP21A2 (21-hydroxylase deficiency; majority of CAH). (concolino2025geneticsincongenital pages 1-2, gunes2025clinicalbiochemicaland pages 1-2) - Additional CAH-related steroidogenesis genes emphasized for rarer CAH forms include CYP11B1, HSD3B2, CYP17A1, STAR. (OpenTargets Search: Congenital adrenal hyperplasia)

Open Targets also associates CAH with these genes and additional steroidogenic components (e.g., CYP11A1, POR), reflecting broader steroidogenesis biology and variant databases. (OpenTargets Search: Congenital adrenal hyperplasia)

4.2 Pathogenic variants and functional consequence

For 21-OHD, loss of 21-hydroxylase reduces conversion of 17-hydroxyprogesterone to 11-deoxycortisol, producing precursor accumulation and downstream androgen excess, and increased ACTH drive. (concolino2025geneticsincongenital pages 1-2)
A practical genotype grouping used clinically links residual activity to phenotype: Group A (no activity → SW), Group B (1–10% → SV), Group C (20–60% → NCCAH). (uslar2023clinicalupdateon pages 6-7)

4.3 Modifier genes / contiguous gene syndromes

The retrieved evidence set does not include direct primary-data details on modifier genes, but highlights that complex HLA-locus recombination events contribute to genotypes and diagnostic complexity. (uslar2023clinicalupdateon pages 6-7)

4.4 Epigenetics and chromosomal abnormalities

No CAH-specific epigenetic signatures or recurrent chromosomal abnormalities were identified in the retrieved evidence set.

5. Environmental information

CAH is principally monogenic. Environmental exposures are not described as causal in the retrieved sources; most “environmental” relevance is via stressors triggering adrenal crisis in cortisol-deficient individuals and via treatment-related adverse effects (chronic supraphysiologic glucocorticoid exposure). (harris2025congenitaladrenalhyperplasia pages 7-9, righi2023longtermcardiometabolicmorbidity pages 1-2)

6. Mechanism / pathophysiology

6.1 Causal chain (21-OHD)

CYP21A2 deficiency → impaired 21-hydroxylation of progesterone/17-hydroxyprogesterone. (concolino2025geneticsincongenital pages 1-2)
Reduced cortisol ± aldosterone production → loss of negative feedback on hypothalamic–pituitary axis. (concolino2025geneticsincongenital pages 1-2)
ACTH elevation → adrenal cortical hyperplasia and increased flux through androgen synthesis pathways. (concolino2025geneticsincongenital pages 1-2, uslar2023clinicalupdateon pages 3-6)
Clinical manifestations: adrenal insufficiency (including neonatal salt-wasting crisis in SW), prenatal virilization in some 46,XX fetuses, postnatal hyperandrogenism (precocious pubarche, acne, hirsutism, menstrual irregularity, fertility issues), and long-term metabolic/bone comorbidity partly mediated by both disease and treatment exposure. (uslar2023clinicalupdateon pages 3-6, gunes2025clinicalbiochemicaland pages 1-2, righi2023longtermcardiometabolicmorbidity pages 1-2)

6.2 Pathway visualization evidence

The steroidogenesis pathway and the CYP21A2 step are shown in a recent genetics review figure (including 17-hydroxyprogesterone and the 21-hydroxylase-catalyzed conversion). (concolino2025geneticsincongenital media e874a3ec)

6.3 Suggested ontology terms (mechanism annotation)

Suggestions (not exhaustively evidenced in the retrieved texts): - GO biological process: steroid biosynthetic process; glucocorticoid biosynthetic process; mineralocorticoid biosynthetic process; androgen biosynthetic process; response to corticotropin. - Cell Ontology (CL): adrenal cortical cell; zona fasciculata cell; zona glomerulosa cell. - UBERON: adrenal gland; adrenal cortex.

7. Anatomical structures affected

Primary: adrenal cortex (site of impaired steroidogenesis and hyperplasia). (concolino2025geneticsincongenital pages 1-2, uslar2023clinicalupdateon pages 3-6)

Secondary / complications: - Gonads/reproductive axis: infertility, menstrual dysfunction; TARTs (testicular adrenal rest tumors) in males. (uslar2023clinicalupdateon pages 9-10) - Cardiometabolic and skeletal systems: obesity, hypertension, dyslipidemia, abnormal glucose homeostasis, osteoporosis/osteopenia. (righi2023longtermcardiometabolicmorbidity pages 1-2, zaric2025metabolicsyndromespectrum pages 12-14)

8. Temporal development

SW classic: onset at birth/early infancy with risk of life-threatening salt-wasting crisis if unrecognized. (uslar2023clinicalupdateon pages 3-6, gunes2025clinicalbiochemicaland pages 1-2)
SV classic: typically recognized in infancy/childhood via hyperandrogenic signs (accelerated growth, advanced bone age, early pubic hair). (gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 3-6)
NCCAH: later onset (childhood/adolescence/adulthood) with hyperandrogenism (acne, hirsutism, menstrual irregularities/infertility). (uslar2023clinicalupdateon pages 3-6, gunes2025clinicalbiochemicaland pages 1-2)

9. Inheritance and population

9.1 Epidemiology (selected recent/representative statistics)

Classic CAH frequency (US, literature estimate in claims paper): ~1:16,000 children. (harasymiw2020attentiondeficithyperactivitydisorderamong pages 2-3)
Nonclassic CAH prevalence (literature estimate in claims paper): ~1:500. (harasymiw2020attentiondeficithyperactivitydisorderamong pages 2-3)
Administrative prevalence in US insured populations (MarketScan/Medicaid, ages 5–18): 10.1 per 100,000 (Commercial) and 7.2 per 100,000 (Medicaid). (harasymiw2020attentiondeficithyperactivitydisorderamong pages 1-2)
Newborn screening cohort (North India hospital program; 2008–2017; n=13,376): confirmed CAH birth prevalence ~1:2,500, with sensitivity 100% and specificity 99.9% for the CAH screening protocol using dried-blood-spot 17-OHP. (verma2020newbornscreeningfor pages 3-4, verma2020newbornscreeningfor pages 1-2)

9.2 Inheritance and recurrence

Autosomal recessive inheritance is consistently stated for 21-OHD CAH. (concolino2025geneticsincongenital pages 1-2, gunes2025clinicalbiochemicaland pages 1-2)
A prenatal diagnosis/screening review notes a 1 in 4 recurrence risk for any child of carrier parents and 1 in 8 risk for an affected female child (reflecting sex-limited virilization concern). (abalı2025antenataldiagnosisand pages 1-2)

9.3 Population genetics

Severe-allele carrier prevalence is summarized as ~2% (1 in 60) in a multidisciplinary review. (uslar2023clinicalupdateon pages 9-10)

10. Diagnostics

Biochemical diagnosis is anchored in 17-hydroxyprogesterone (17-OHP) measurement, assay-aware thresholds, ACTH stimulation testing, and molecular confirmation when indicated.

Test/biomarker	Specimen & timing	Decision thresholds/cutoffs	Interpretation/use	Supporting citation
Basal 17-hydroxyprogesterone (17-OHP) by immunoassay (suggested LOINC-style concept: 17-hydroxyprogesterone [Mass/volume] in Serum or Plasma)	Fasting blood/plasma, before 9:00 AM; in menstruating women, sample in early follicular phase	>2 ng/mL suspicious; >7–10 ng/mL considered diagnostic by consensus in reviewed clinical update	First-line biochemical screen for suspected 21-hydroxylase deficiency; values in indeterminate range should prompt ACTH stimulation or additional testing	(uslar2023clinicalupdateon pages 3-6)
Basal 17-hydroxyprogesterone (17-OHP) by LC-MS/MS (suggested LOINC-style concept: 17-hydroxyprogesterone [Mass/volume] in Serum or Plasma by LC-MS/MS)	Fasting blood/plasma, before 9:00 AM; early follicular phase if cycling	>0.8 ng/mL suspicious	Preferred analytical method in the 2023 multidisciplinary review because of improved specificity; used as the main basal threshold before confirmatory ACTH stimulation	(uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 6-7)
Basal 17-hydroxyprogesterone (17-OHP), conventional diagnostic threshold from 2025 review (suggested LOINC-style concept: 17-hydroxyprogesterone [Mass/volume] in Serum)	Early morning blood sample	>1000 ng/dL supports diagnosis of 21-OHD	High morning basal 17-OHP strongly supports CAH due to 21-hydroxylase deficiency; lower borderline values require ACTH stimulation	(gunes2025clinicalbiochemicaland pages 1-2)
Borderline basal 17-hydroxyprogesterone (17-OHP) range requiring ACTH test (suggested LOINC-style concept: 17-hydroxyprogesterone [Mass/volume] in Serum)	Early morning blood sample	200–1000 ng/dL = borderline range	Borderline basal results should be followed by ACTH stimulation testing to clarify nonclassic or less severe 21-OHD	(gunes2025clinicalbiochemicaland pages 1-2)
ACTH stimulation test with 17-OHP readout by LC-MS/MS (suggested LOINC-style concepts: Corticotropin stimulation panel; 17-hydroxyprogesterone [Mass/volume] in Serum or Plasma post stimulation)	250 µg ACTH (i.m. or i.v.); stimulated blood sampling after standard ACTH test	Stimulated 17-OHP >3 ng/mL confirms diagnosis in cited LC-MS/MS framework	Recommended confirmatory test for intermediate/borderline cases and to assess cortisol response in NCCAH	(uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 6-7)
ACTH stimulation test (procedure detail)	250 µg ACTH intramuscular or intravenous	Procedure threshold not itself diagnostic; used when basal 17-OHP is indeterminate or ACTH reserve/cortisol response is questioned	Confirms CAH/NCCAH in equivocal cases and helps assess adrenal cortisol reserve; genotype testing is recommended when stimulated 17-OHP is nondiagnostic or ACTH testing is unavailable	(uslar2023clinicalupdateon pages 6-7)
Genotype testing (CYP21A2) (suggested LOINC-style concept: CYP21A2 gene targeted mutation analysis / full gene analysis)	Blood or DNA sample; no timing requirement	No numeric cutoff; indicated when biochemical profile is suspicious, ACTH testing is incomplete/unavailable, or for recurrence-risk interpretation	Supports molecular confirmation, genotype–phenotype interpretation, parental carrier assessment, and counseling	(gunes2025clinicalbiochemicaland pages 1-2, abalı2025antenataldiagnosisand pages 1-2, uslar2023clinicalupdateon pages 6-7)
Newborn screening 17-OHP on dried blood spot, term infant (suggested LOINC-style concept: 17-hydroxyprogesterone [Moles/volume] in Dried blood spot)	Newborn dried blood specimen	<30 nmol/L normal; 30–90 nmol/L intermediate; >90 nmol/L positive	Population screening for severe CAH; intermediate/positive samples in the India cohort were repeated on a separate blood spot before reporting	(verma2020newbornscreeningfor pages 1-2, verma2020newbornscreeningfor pages 2-3)
Newborn screening 17-OHP on dried blood spot, preterm infant (suggested LOINC-style concept: 17-hydroxyprogesterone [Moles/volume] in Dried blood spot)	Newborn dried blood specimen	<60 nmol/L normal; 60–90 nmol/L intermediate; >90 nmol/L positive	Adjusted newborn-screening interpretation for prematurity in the India cohort protocol	(verma2020newbornscreeningfor pages 1-2, verma2020newbornscreeningfor pages 2-3)
Newborn screening program performance (India cohort)	13,376 newborns screened, dried blood 17-OHP	15 screen-positive, 5 true positive, 10 false positive; false-positive rate 0.07%; PPV 33.3%; NPV 100%; sensitivity 100%; specificity 99.9%; birth prevalence 0.04% (5/13,376) ≈ 1:2,500	Illustrates real-world performance of newborn screening for CAH using 17-OHP in a hospital-based Indian cohort	(verma2020newbornscreeningfor pages 1-2, verma2020newbornscreeningfor pages 3-4)
Confirmatory steroid panel after positive newborn screen (suggested LOINC-style concepts: 17-hydroxyprogesterone [Mass/volume] in Serum; Cortisol [Mass/volume] in Serum; Dehydroepiandrosterone [Mass/volume] in Serum)	Fresh serum/blood draw after recall; serum cortisol measured at 8 AM and 4 PM in cited cohort	No single universal cutoff provided in extracted text	Used to confirm abnormal dried-blood-spot screening results after recall of screen-positive newborns	(verma2020newbornscreeningfor pages 2-3)

Table: This table summarizes diagnostic tests and cutoffs for congenital adrenal hyperplasia due to 21-hydroxylase deficiency, including basal and stimulated 17-OHP thresholds, assay-specific interpretation, and newborn screening metrics. It is useful as a compact reference for comparing immunoassay, LC-MS/MS, ACTH stimulation, and screening-based approaches.

Key points from a 2023 multidisciplinary program review include: (i) LC–MS/MS is recommended to improve steroid specificity; (ii) basal sampling should be fasting before 9 AM, and for cycling women in the early follicular phase; (iii) ACTH stimulation (250 µg i.m./i.v.) is used to confirm intermediate cases; and (iv) genotype testing is recommended when biochemical evaluation is suspicious or incomplete. (uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 6-7)

Newborn screening implementation (real-world program example): A decade-long North Indian hospital screening program used dried-blood-spot 17-OHP with term/preterm cutoffs, identified 15 screen positives with 5 true positives (PPV 33.3%), and reported sensitivity 100% and specificity 99.9%. (verma2020newbornscreeningfor pages 3-4, verma2020newbornscreeningfor pages 1-2)

11. Outcomes / prognosis

11.1 Cardiometabolic and bone morbidity (recent data)

A 2023 multicentre specialist survey of 244 adults with classic 21-OHD CAH (median age 33 years) found 30% (73/244) were treated for ≥1 of six major comorbidity domains; among treated comorbidities, osteoporosis/osteopenia treatment was most frequent (59%), followed by hyperlipidaemia (23%), type 2 diabetes/hyperinsulinaemia (22%), hypertension (14%), cardiovascular disease (11%), and obesity (4%). (righi2023longtermcardiometabolicmorbidity pages 1-2)

A 2025 pediatric systematic review synthesizing studies through 2024 reports increased cardiometabolic risk factors in children with classic CAH; one included dataset reported 58% systolic hypertension and 24% diastolic hypertension with additional abnormalities in nocturnal dipping and subclinical vascular markers. (zaric2025metabolicsyndromespectrum pages 12-14)

11.2 Autoimmune comorbidity

A Swedish national cohort study (n=714 21-OHD; 71,400 controls) found autoimmune disorders in 7.4% vs 5.1% of controls (RR 1.47, 95% CI 1.13–1.91), with increased autoimmune endocrine and thyroid disorders. (falhammar2019increasedriskof pages 1-2)

12. Treatment

Standard of care focuses on replacing deficient hormones and limiting androgen excess, balanced against harms of chronic supraphysiologic glucocorticoid exposure.

Intervention	Mechanism/goal	Typical use case	Key quantitative data	Safety/limitations	MAXO term suggestions	Citations
Hydrocortisone replacement (children)	Replace cortisol deficiency; suppress excess ACTH-driven adrenal androgen production while minimizing hypercortisolism	First-line long-term therapy in pediatric classic 21-hydroxylase deficiency	Preferred regimen 10–15 mg/m²/day divided every 8 h (uslar2023clinicalupdateon pages 6-7)	Conventional dosing does not reproduce physiologic circadian cortisol rhythm; excess exposure is linked to obesity, hypertension, osteoporosis, and adverse cardiometabolic profile (righi2023longtermcardiometabolicmorbidity pages 1-2)	MAXO: glucocorticoid replacement therapy; hydrocortisone administration	(uslar2023clinicalupdateon pages 6-7, righi2023longtermcardiometabolicmorbidity pages 1-2)
Hydrocortisone replacement (adults)	Cortisol replacement with partial androgen control	Standard maintenance therapy in adults with classic CAH	Suggested regimen 15–25 mg/day, with last dose ≥6 h before bedtime (uslar2023clinicalupdateon pages 6-7)	Undertreatment leaves androgen excess uncontrolled; overtreatment increases metabolic and bone morbidity (uslar2023clinicalupdateon pages 6-7, righi2023longtermcardiometabolicmorbidity pages 1-2)	MAXO: glucocorticoid replacement therapy; hydrocortisone administration	(uslar2023clinicalupdateon pages 6-7, righi2023longtermcardiometabolicmorbidity pages 1-2)
Stress-dose glucocorticoids / sick-day management	Prevent adrenal crisis during physiological stress	Major illness, surgery, trauma, childbirth; also emphasized as lifelong emergency management in severe CAH	Review evidence notes lifelong need for “sick day” dosing in response to stressors (harris2025congenitaladrenalhyperplasia pages 7-9)	Required because impaired stress response persists despite routine replacement; inadequate stress dosing risks adrenal crisis (harris2025congenitaladrenalhyperplasia pages 7-9)	MAXO: stress-dose steroid therapy; adrenal crisis prophylaxis	(harris2025congenitaladrenalhyperplasia pages 7-9)
Neonatal salt-wasting crisis hydrocortisone regimen	Emergency glucocorticoid rescue in adrenal crisis / severe SW-CAH	Neonates with salt-wasting presentation or adrenal insufficiency	Initial hydrocortisone bolus 5 mg/kg, then 25 mg/24 h infusion or divided doses (uslar2023clinicalupdateon pages 6-7)	Requires urgent electrolyte/fluid management and specialist care; delay can be life-threatening (gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 6-7)	MAXO: emergency hydrocortisone therapy; adrenal crisis treatment	(gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 6-7)
Mineralocorticoid replacement (fludrocortisone)	Replace aldosterone deficiency; maintain sodium balance and blood pressure	Classic salt-wasting CAH; many adults continue combined GC+MC therapy	In one adult cohort, 174/244 (71%) received fludrocortisone with glucocorticoids (righi2023longtermcardiometabolicmorbidity pages 2-3)	Requires monitoring of plasma renin and electrolytes; annual renin monitoring is recommended with target at the upper normal limit (uslar2023clinicalupdateon pages 6-7, uslar2023clinicalupdateon pages 9-10)	MAXO: mineralocorticoid replacement therapy; fludrocortisone administration	(uslar2023clinicalupdateon pages 6-7, righi2023longtermcardiometabolicmorbidity pages 2-3, uslar2023clinicalupdateon pages 9-10)
Monitoring during glucocorticoid/mineralocorticoid therapy	Optimize replacement and avoid over/undertreatment	Routine follow-up in classic and selected nonclassic CAH	Recommended monitoring includes plasma renin, electrolytes, cortisol, aldosterone, androstenedione, DHEAS; annual BP and BMI monitoring advised (uslar2023clinicalupdateon pages 6-7, uslar2023clinicalupdateon pages 9-10)	Biomarkers vary by assay, timing, age, and medication schedule; standardization remains challenging (uslar2023clinicalupdateon pages 9-10)	MAXO: therapeutic drug monitoring; endocrine laboratory monitoring	(uslar2023clinicalupdateon pages 6-7, uslar2023clinicalupdateon pages 9-10)
Combined oral contraceptives (OCPs) for NCCAH hyperandrogenism	Suppress ovarian androgen production and improve hirsutism/acne/cycle control	First-line adjunct in women with NCCAH-related hirsutism/acne	Identified as first-line androgen-management option in NCCAH (uslar2023clinicalupdateon pages 9-10)	Symptomatic treatment; does not correct underlying adrenal enzyme defect (uslar2023clinicalupdateon pages 9-10)	MAXO: oral contraceptive therapy; anti-hyperandrogenism management	(uslar2023clinicalupdateon pages 9-10)
Spironolactone adjunct	Antiandrogen therapy for persistent hirsutism/acne	Add-on when OCPs alone are insufficient in NCCAH	Suggested dose 50–100 mg/day (uslar2023clinicalupdateon pages 9-10)	Adjunctive/symptomatic rather than disease-modifying; standard antiandrogen precautions apply (uslar2023clinicalupdateon pages 9-10)	MAXO: antiandrogen therapy; spironolactone administration	(uslar2023clinicalupdateon pages 9-10)
Flutamide adjunct	Androgen receptor blockade to improve hyperandrogenic symptoms	Alternative add-on antiandrogen in NCCAH	Suggested dose 62.5–125 mg/day (uslar2023clinicalupdateon pages 9-10)	Adjunctive/symptomatic therapy; use limited by known antiandrogen safety concerns (not detailed in excerpt) (uslar2023clinicalupdateon pages 9-10)	MAXO: antiandrogen therapy; flutamide administration	(uslar2023clinicalupdateon pages 9-10)
Crinecerfont	CRF1 receptor antagonist that lowers ACTH drive, enabling androgen control with lower glucocorticoid doses	Emerging adjunct for classic CAH with need to reduce supraphysiologic glucocorticoid exposure	Phase 3 adults: glucocorticoid dose change −27.3% vs −10.3% placebo; 62.7% vs 17.5% achieved physiologic GC dose; week-4 androstenedione −299 ng/dL vs +45.5 ng/dL; P<0.001 for primary comparisons (auchus2024phase3trial pages 1-3)	Most common adverse events were fatigue and headache; intended as adjunct, not replacement for mandatory steroid therapy (auchus2024phase3trial pages 1-3)	MAXO: corticotropin-releasing hormone receptor antagonist therapy; glucocorticoid-sparing therapy	(auchus2024phase3trial pages 1-3)
Tildacerfont	Investigational CRF1 receptor antagonist to reduce ACTH-driven androgen excess	Experimental adjunct in adults/children with CAH	Adult Phase 2b trials NCT04457336 and NCT04544410; pediatric Phase 2 NCT05128942; listed statuses were terminated in retrieved ClinicalTrials.gov summaries (NCT04457336 chunk 3)	Development status uncertain/limited by trial termination in retrieved records; no phase 3 efficacy data in current evidence set	MAXO: corticotropin-releasing hormone receptor antagonist therapy	(NCT04457336 chunk 3)
Gene therapy (BBP-631 / gene-transfer approaches)	Deliver functional CYP21A2 to restore steroidogenesis	Experimental treatment for classic CAH	Review notes BBP-631 (AAV5 carrying wild-type CYP21A2) in phase 1/2 and cites preclinical rescue of steroidogenesis in Cyp21-deficient mice/non-human primates; ClinicalTrials.gov lists NCT04783181 as an active-not-recruiting phase 1/2 gene therapy study with planned enrollment 8 (glazova2023modelsofcongenital pages 2-4)	Experimental; long-term durability, adrenal targeting, and safety remain under investigation (glazova2023modelsofcongenital pages 2-4)	MAXO: gene replacement therapy; adeno-associated viral gene therapy	(glazova2023modelsofcongenital pages 2-4)
Ultradian subcutaneous hydrocortisone infusion	More physiologic cortisol delivery pattern than conventional oral dosing	Experimental/selected use in adrenal insufficiency and CAH	Clinical trial NCT02096510 completed; phase 1/2 interventional study with 8 participants in Addison disease and CAH (clinical trial summary) (NCT02096510 chunk 2)	Limited evidence base and specialized delivery burden; not routine standard-of-care in retrieved evidence	MAXO: continuous subcutaneous hydrocortisone infusion	(NCT02096510 chunk 2)

Table: This table summarizes standard, adjunctive, emerging, and experimental interventions for congenital adrenal hyperplasia due to 21-hydroxylase deficiency, with quantitative dosing or trial data where available. It is designed to support rapid comparison of treatment goals, use cases, limitations, and ontology-aligned action terms.

12.1 Standard pharmacotherapy (real-world implementation)

Glucocorticoid replacement: hydrocortisone is preferred; one review provides typical dosing ranges (children 10–15 mg/m²/day, adults 15–25 mg/day) and an emergency neonatal regimen (bolus + infusion). (uslar2023clinicalupdateon pages 6-7)
Mineralocorticoid replacement: fludrocortisone and monitoring of renin/electrolytes are emphasized for SW-CAH; in one adult cohort, 71% received fludrocortisone. (righi2023longtermcardiometabolicmorbidity pages 2-3, uslar2023clinicalupdateon pages 9-10)
Adjunct hyperandrogenism therapy in NCCAH: OCPs as first-line, with antiandrogens (spironolactone, flutamide) as add-ons when needed. (uslar2023clinicalupdateon pages 9-10)

12.2 Recent developments (2023–2024 prioritized)

Crinecerfont (CRF1 receptor antagonist): In a randomized phase 3 trial (NEJM, Aug 2024; ClinicalTrials.gov NCT04490915), crinecerfont enabled clinically meaningful glucocorticoid dose reduction while maintaining androstenedione control: −27.3% dose reduction vs −10.3% placebo (P<0.001), and 62.7% vs 17.5% achieved physiologic glucocorticoid doses. Androstenedione fell by −299 ng/dL at week 4 vs an increase with placebo; fatigue and headache were the most common adverse events. (auchus2024phase3trial pages 1-3)

12.3 Experimental / pipeline approaches

Gene therapy: A 2023 model-and-translation review describes an AAV5 gene therapy candidate (BBP-631, CYP21A2) in phase 1/2, and ClinicalTrials.gov lists a CAH gene therapy study NCT04783181 (planned enrollment 8). (glazova2023modelsofcongenital pages 2-4)
Physiologic replacement strategies: ultradian subcutaneous hydrocortisone infusion has been studied in a completed phase 1/2 trial including CAH (NCT02096510). (NCT02096510 chunk 2)

13. Prevention

13.1 Primary prevention

Not applicable in the traditional exposure-avoidance sense for a monogenic, autosomal recessive condition.

13.2 Secondary prevention: newborn screening

Multiple reviews advocate newborn screening for early detection of severe forms to reduce mortality and improve management/sex assignment; a large hospital-based India cohort demonstrates feasibility and quantifies performance. (uslar2023clinicalupdateon pages 3-6, abalı2025antenataldiagnosisand pages 1-2, verma2020newbornscreeningfor pages 3-4)

13.3 Genetic counseling / reproductive options

Accurate molecular diagnosis (e.g., CYP21A2 sequencing plus MLPA in certified laboratories) is emphasized for counseling; prenatal diagnosis and management remain technically and ethically complex. (abalı2025antenataldiagnosisand pages 1-2)

14. Other species / natural disease

CAH-like syndromes and enzyme deficiencies have been reported in domestic animals (e.g., cats; dogs), and non-traditional models (ferrets, pigs, spiny mice) are reviewed as potentially useful for adrenal biology due to closer adrenal anatomy/steroidogenesis than rodents. (bilyalova2024nonclassicalanimalmodels pages 2-4)

15. Model organisms

15.1 Zebrafish (in vivo 21-OHD modeling)

A TALEN-generated zebrafish cyp21a2 null model showed reduced cortisol, increased 17-OHP and 21-deoxycortisol, HPI-axis upregulation, and interrenal hyperplasia, supporting use for systemic consequences of glucocorticoid deficiency; the paper cites CAH incidence ~1 in 10,000–1 in 15,000. (eachus2017geneticdisruptionof pages 1-2)

15.2 Mouse models (including humanized CYP21A2)

A 2024 paper reports a viable humanized mouse model carrying the clinically relevant CYP21A2 p.R484Q variant that develops adrenal hyperplasia and steroid abnormalities and displays sex-specific reproductive phenotypes (female infertility). (thirumalasetty2024ahumanizedand pages 1-2)

A 2022 study established a humanized CYP21A2 mouse platform (Cyp21a1 replaced by human CYP21A2) that is phenotypically normal, intended as a base for introducing pathogenic mutations. (schubert2022cyp21a2geneexpression pages 1-2)

15.3 Model limitations (expert analysis)

A review of adrenal genetic disorder models emphasizes that rodent adrenal steroidogenesis differs from humans (e.g., lack of adrenal 17-hydroxylase and androgen production), limiting recapitulation of human virilization/hyperandrogenism phenotypes. (beuschlein2023animalmodelsof pages 2-4)

Direct abstract quotes (selected, for anchoring key claims)

Uslar et al. (2023) describe CAH as “characterized by the overproduction of androgen, along with variable degrees of cortisol and aldosterone deficiency.” (uslar2023clinicalupdateon pages 3-6)
Auchus et al. (NEJM 2024) conclude: “crinecerfont permitted reduction of supraphysiological glucocorticoid doses, including to physiological range…” (auchus2024phase3trial pages 1-3)
Verma et al. (2020) report: “From January 2008 through December 2017, 13,376 newborns were screened… by measuring… 17-hydroxyprogesterone…” and report CAH birth prevalence 1:2,500 with “100% sensitivity and >99% specificity.” (verma2020newbornscreeningfor pages 1-2)

Evidence-backed subtype summary table

CAH subtype / etiology	Causal gene(s)	Key biochemical hallmarks	Typical onset	Key reference(s)
21-hydroxylase deficiency, classic salt-wasting (SW)	CYP21A2	Cortisol deficiency with aldosterone deficiency; excess adrenal androgens; neonatal salt-wasting crisis with electrolyte disturbance; residual enzyme activity typically <1% (uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 6-7, concolino2025geneticsincongenital pages 1-2)	Neonatal / early infancy (uslar2023clinicalupdateon pages 3-6, concolino2025geneticsincongenital pages 1-2)	Uslar et al., 2023, J Clin Med, https://doi.org/10.3390/jcm12093128 (uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 6-7); Concolino & Falhammar, 2025, J Endocrine Soc, https://doi.org/10.1210/jendso/bvaf018 (concolino2025geneticsincongenital pages 1-2)
21-hydroxylase deficiency, classic simple virilizing (SV)	CYP21A2	Cortisol deficiency with preserved mineralocorticoid function; androgen excess with virilization / precocious pubarche / accelerated growth; residual activity about 1–2% or 1–10% depending on grouping scheme (uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 6-7)	Infancy / childhood (gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 3-6)	Uslar et al., 2023, J Clin Med, https://doi.org/10.3390/jcm12093128 (uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 6-7); Güneş et al., 2025, JCRPE, https://doi.org/10.4274/jcrpe.galenos.2024.2024-6-6-s (gunes2025clinicalbiochemicaland pages 1-2)
21-hydroxylase deficiency, nonclassic (NCCAH)	CYP21A2	Mild cortisol impairment with hyperandrogenism; morning 17-OHP often elevated, ACTH-stimulated increase used diagnostically; residual activity about 20–50% (or 20–60% in mutation grouping) (uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 6-7)	Late childhood, adolescence, or adulthood (gunes2025clinicalbiochemicaland pages 1-2, uslar2023clinicalupdateon pages 3-6)	Uslar et al., 2023, J Clin Med, https://doi.org/10.3390/jcm12093128 (uslar2023clinicalupdateon pages 3-6, uslar2023clinicalupdateon pages 6-7); Güneş et al., 2025, JCRPE, https://doi.org/10.4274/jcrpe.galenos.2024.2024-6-6-s (gunes2025clinicalbiochemicaland pages 1-2)
11β-hydroxylase deficiency	CYP11B1	Inability to produce cortisol and aldosterone with excessive adrenal androgen production; laboratory/clinical features can resemble 21-OHD but mineralocorticoid deficiency findings are not observed (OpenTargets Search: Congenital adrenal hyperplasia)	Childhood / early life (not further specified in extracted evidence) (OpenTargets Search: Congenital adrenal hyperplasia)	İsakoca et al., 2025, JCRPE, https://doi.org/10.4274/jcrpe.galenos.2024.2024-6-21-s (OpenTargets Search: Congenital adrenal hyperplasia)
17α-hydroxylase deficiency	CYP17A1	Impaired sex steroid synthesis; 46,XY DSD in boys and estrogen deficiency with immature puberty / primary amenorrhea in girls (OpenTargets Search: Congenital adrenal hyperplasia)	Childhood to adolescence / puberty (OpenTargets Search: Congenital adrenal hyperplasia)	İsakoca et al., 2025, JCRPE, https://doi.org/10.4274/jcrpe.galenos.2024.2024-6-21-s (OpenTargets Search: Congenital adrenal hyperplasia)
3β-hydroxysteroid dehydrogenase deficiency	HSD3B2	Early impairment of adrenal and gonadal steroid biosynthesis; inadequate virilization in boys, variable virilization in girls; may present with salt-wasting crisis (OpenTargets Search: Congenital adrenal hyperplasia)	Neonatal / infancy, sometimes delayed puberty (OpenTargets Search: Congenital adrenal hyperplasia)	İsakoca et al., 2025, JCRPE, https://doi.org/10.4274/jcrpe.galenos.2024.2024-6-21-s (OpenTargets Search: Congenital adrenal hyperplasia)
Lipoid CAH	STAR	Near-complete deficiency of adrenal and gonadal steroid hormones with progressive accumulation of cholesterol esters in adrenal gland; severe salt wasting (OpenTargets Search: Congenital adrenal hyperplasia)	First year of life (OpenTargets Search: Congenital adrenal hyperplasia)	İsakoca et al., 2025, JCRPE, https://doi.org/10.4274/jcrpe.galenos.2024.2024-6-21-s (OpenTargets Search: Congenital adrenal hyperplasia)

Table: This table compacts the main congenital adrenal hyperplasia etiologies discussed in the gathered evidence, linking each subtype to its causal gene, core biochemical pattern, and typical onset. It is useful as a quick-reference map for differentiating common 21-hydroxylase deficiency forms from rarer enzyme defects.

Notes on evidence gaps for this run

Specific OMIM, Orphanet (ORPHA), MeSH, and ICD-11 identifiers were not retrieved as full-text evidence in this tool run; the report therefore does not assert them.
Detailed ClinVar-style variant lists (HGVS nomenclature, allele frequencies in gnomAD) and epigenetic studies were not present in retrieved evidence and are not enumerated.

Key source URLs (with publication dates)

Uslar T et al. Journal of Clinical Medicine 2023-04. https://doi.org/10.3390/jcm12093128 (uslar2023clinicalupdateon pages 3-6)
Auchus RJ et al. New England Journal of Medicine 2024-08. https://doi.org/10.1056/NEJMoa2404656 (auchus2024phase3trial pages 1-3)
Concolino P, Falhammar H. Journal of the Endocrine Society 2025-01. https://doi.org/10.1210/jendso/bvaf018 (concolino2025geneticsincongenital pages 1-2)
Righi B et al. Endocrine 2023-03. https://doi.org/10.1007/s12020-023-03330-w (righi2023longtermcardiometabolicmorbidity pages 1-2)
Verma J et al. Journal of Pediatric Intensive Care 2020-10. https://doi.org/10.1055/s-0039-1698424 (verma2020newbornscreeningfor pages 1-2)

References

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(concolino2025geneticsincongenital media e874a3ec): Paola Concolino and Henrik Falhammar. Genetics in congenital adrenal hyperplasia due to 21-hydroxylase deficiency and clinical implications. Journal of the Endocrine Society, Jan 2025. URL: https://doi.org/10.1210/jendso/bvaf018, doi:10.1210/jendso/bvaf018. This article has 7 citations and is from a peer-reviewed journal.
(harasymiw2020attentiondeficithyperactivitydisorderamong pages 2-3): Lauren A Harasymiw, Scott D Grosse, and Kyriakie Sarafoglou. Attention-deficit/hyperactivity disorder among us children and adolescents with congenital adrenal hyperplasia. Journal of the Endocrine Society, Oct 2020. URL: https://doi.org/10.1210/jendso/bvaa152, doi:10.1210/jendso/bvaa152. This article has 9 citations and is from a peer-reviewed journal.
(harasymiw2020attentiondeficithyperactivitydisorderamong pages 1-2): Lauren A Harasymiw, Scott D Grosse, and Kyriakie Sarafoglou. Attention-deficit/hyperactivity disorder among us children and adolescents with congenital adrenal hyperplasia. Journal of the Endocrine Society, Oct 2020. URL: https://doi.org/10.1210/jendso/bvaa152, doi:10.1210/jendso/bvaa152. This article has 9 citations and is from a peer-reviewed journal.
(verma2020newbornscreeningfor pages 3-4): Jyotsna Verma, Papai Roy, Divya C. Thomas, Geetu Jhingan, Azad Singh, Sunita Bijarnia-Mahay, and Ishwar C. Verma. Newborn screening for congenital hypothyroidism, congenital adrenal hyperplasia, and glucose-6-phosphate dehydrogenase deficiency for improving health care in india. Journal of Pediatric Intensive Care, 09:040-044, Oct 2020. URL: https://doi.org/10.1055/s-0039-1698424, doi:10.1055/s-0039-1698424. This article has 19 citations.
(verma2020newbornscreeningfor pages 2-3): Jyotsna Verma, Papai Roy, Divya C. Thomas, Geetu Jhingan, Azad Singh, Sunita Bijarnia-Mahay, and Ishwar C. Verma. Newborn screening for congenital hypothyroidism, congenital adrenal hyperplasia, and glucose-6-phosphate dehydrogenase deficiency for improving health care in india. Journal of Pediatric Intensive Care, 09:040-044, Oct 2020. URL: https://doi.org/10.1055/s-0039-1698424, doi:10.1055/s-0039-1698424. This article has 19 citations.
(NCT04457336 chunk 3): A Ph2b to Evaluate Clinical Efficacy and Safety of Tildacerfont in Adult CAH. Spruce Biosciences. 2020. ClinicalTrials.gov Identifier: NCT04457336
(NCT02096510 chunk 2): Ultradian Subcutaneous Hydrocortisone Infusion in Addison Disease and Congenital Adrenal Hyperplasia. Haukeland University Hospital. 2014. ClinicalTrials.gov Identifier: NCT02096510
(bilyalova2024nonclassicalanimalmodels pages 2-4): Alina Bilyalova, Airat Bilyalov, Nikita Filatov, Elena Shagimardanova, Andrey Kiyasov, Maria Vorontsova, and Oleg Gusev. Non-classical animal models for studying adrenal diseases: advantages, limitations, and implications for research. Laboratory Animal Research, Jun 2024. URL: https://doi.org/10.1186/s42826-024-00212-8, doi:10.1186/s42826-024-00212-8. This article has 4 citations.
(schubert2022cyp21a2geneexpression pages 1-2): Tina Schubert, Nicole Reisch, Ronald Naumann, Ilka Reichardt, Dana Landgraf, Friederike Quitter, Shamini Ramkumar Thirumalasetty, Anne-Kristin Heninger, Mihail Sarov, Mirko Peitzsch, Angela Huebner, and Katrin Koehler. Cyp21a2 gene expression in a humanized 21-hydroxylase mouse model does not affect adrenocortical morphology and function. Journal of the Endocrine Society, Apr 2022. URL: https://doi.org/10.1210/jendso/bvac062, doi:10.1210/jendso/bvac062. This article has 8 citations and is from a peer-reviewed journal.
(beuschlein2023animalmodelsof pages 2-4): Felix Beuschlein. Animal models of adrenal genetic disorders. ArXiv, pages 323-329, Jan 2023. URL: https://doi.org/10.1016/b978-0-12-416006-4.00026-0, doi:10.1016/b978-0-12-416006-4.00026-0. This article has 2 citations.

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Inheritance

Subtypes

Pathophysiology

Pathograph

Phenotypes

Genetic Associations

Medical Actions

Biochemical Markers

Diagnosis

Related Datasets

Clinical Trials

Source YAML

References & Deep Research

References

Deep Research

Disease Characteristics Research Template

Target Disease

Research Objectives

1. Disease Information

2. Etiology

3. Phenotypes

4. Genetic/Molecular Information

5. Environmental Information

6. Mechanism / Pathophysiology

7. Anatomical Structures Affected

8. Temporal Development

9. Inheritance and Population

10. Diagnostics

11. Outcome/Prognosis

12. Treatment

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Citation Requirements

Output Format

Congenital Adrenal Hyperplasia (CAH) — Disease Characteristics Research Report (Mendelian)

Target disease and scope

1. Disease information

1.1 Concise overview

1.2 Key identifiers (available in retrieved evidence)

1.3 Common synonyms / alternative names

1.4 Evidence provenance type

2. Etiology

2.1 Disease causal factors

2.2 Risk factors

2.3 Protective factors

2.4 Gene–environment interactions

3. Phenotypes (clinical spectrum)

3.1 Current clinical classification

3.2 Phenotype list with ontology suggestions

4. Genetic / molecular information

4.1 Causal genes (human)

4.2 Pathogenic variants and functional consequence

4.3 Modifier genes / contiguous gene syndromes

4.4 Epigenetics and chromosomal abnormalities

5. Environmental information

6. Mechanism / pathophysiology

6.1 Causal chain (21-OHD)

6.2 Pathway visualization evidence

6.3 Suggested ontology terms (mechanism annotation)

7. Anatomical structures affected

8. Temporal development

9. Inheritance and population

9.1 Epidemiology (selected recent/representative statistics)

9.2 Inheritance and recurrence

9.3 Population genetics

10. Diagnostics

11. Outcomes / prognosis

11.1 Cardiometabolic and bone morbidity (recent data)

11.2 Autoimmune comorbidity

12. Treatment

12.1 Standard pharmacotherapy (real-world implementation)

12.2 Recent developments (2023–2024 prioritized)

12.3 Experimental / pipeline approaches

13. Prevention

13.1 Primary prevention

13.2 Secondary prevention: newborn screening

13.3 Genetic counseling / reproductive options