Acrodysostosis

Mendelian MONDO:0019797 Pathograph 27 Show in embeddings browser hereditary disease skeletal dysplasia

Acrodysostosis is a skeletal dysplasia characterized by severe brachydactyly, cone-shaped epiphyses, midface and nasal hypoplasia, short stature, and variable endocrine and neurodevelopmental involvement. Molecularly defined disease comprises PRKAR1A-related type 1 (iPPSD4) and PDE4D-related type 2 (iPPSD5), which disturb cAMP-PKA signaling through distinct mechanisms.

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1
Inheritance
7
Pathophys.
13
Phenotypes
3
Hypotheses
2
Gaps
27
Pathograph
2
Genes
6
Medical Actions
2
Subtypes
3
Differentials
1
Trials
1
Deep Research
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Classifications

ISDS Skeletal Nosology
acromelic dysplasias
👪

Inheritance

1
Autosomal dominant HP:0000006
Acrodysostosis is autosomal dominant. Most molecularly documented cases are sporadic and caused by heterozygous de novo variants, while rare familial PDE4D-related pedigrees demonstrate vertical transmission and variable expressivity.
Autosomal dominant inheritance
Show evidence (2 references)
PMID:23043190 SUPPORT Human Clinical
"All patients had heterozygous de novo mutations."
All 16 unrelated individuals in this molecular cohort had heterozygous de novo PRKAR1A or PDE4D variants.
PMID:28515031 SUPPORT Human Clinical
"We report on a rare multigenerational familial case of acrodysostosis type 2 due to a novel autosomal dominantly inherited PDE4D mutation."
A multigenerational family confirms autosomal dominant PDE4D transmission and qualifies the predominance of de novo cases.
◆

Subtypes

2
Acrodysostosis type 1 (PRKAR1A; iPPSD4) MONDO:0007044
PRKAR1A hgnc:9388 HUGO Gene Nomenclature Committee (hgnc) Relation: this subtype is caused by variation in this gene This subtype is caused by variation in PRKAR1A (hgnc:9388). hgnc:9388 is a gene from the HUGO Gene Nomenclature Committee.
Type 1 is caused by heterozygous PRKAR1A variants that impair cAMP-dependent activation of type I PKA. PTH and TSH resistance are characteristic, although the overall phenotype remains variable.
Show evidence (1 reference)
PMID:42104421 SUPPORT Other
"It is caused by heterozygous mutations in PRKAR1A, which encodes the type Iα regulatory subunit (RIα) of protein kinase A (PKA), a central mediator of cyclic AMP (cAMP)-dependent signalling."
The 2026 mechanistic review defines the PRKAR1A-related subtype and its affected PKA regulatory subunit.
Acrodysostosis type 2 (PDE4D; iPPSD5) MONDO:0013822
PDE4D hgnc:8783 HUGO Gene Nomenclature Committee (hgnc) Relation: this subtype is caused by variation in this gene This subtype is caused by variation in PDE4D (hgnc:8783). hgnc:8783 is a gene from the HUGO Gene Nomenclature Committee.
Type 2 is caused by heterozygous PDE4D variants. Facial dysostosis and neurodevelopmental involvement are often prominent; hormone resistance is less typical but has been reported.
Show evidence (1 reference)
PMID:29016851 SUPPORT In Vitro
"Type 2 acrodysostosis (ACRDYS2), a rare developmental skeletal dysplasia characterized by short stature, severe brachydactyly and facial dysostosis, is caused by mutations in the phosphodiesterase (PDE) 4D (PDE4D) gene."
The functional study defines PDE4D as the gene responsible for acrodysostosis type 2.
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Mechanistic Hypotheses

3
PRKAR1A activation-resistant PKA signal-decoding model
prkar1a_signal_decoding CANONICAL Type 1
Evidence balance 1 support
Mutant RIα incorporates into type I PKA holoenzymes but responds poorly to physiological cAMP, retaining catalytic subunits and imposing a dominant-negative constraint on timed PKA activation.
Pathograph links
PRKAR1A Activation-Resistant PKA Holoenzymes -> Skeletal Chondrocyte and Endochondral Ossification Dysfunction INDIRECT KNOWN INTERMEDIATES Impaired RIα-dependent PKA decoding disrupts growth-plate signaling and chondrocyte maturation. Intermediates: Disruption of the growth-plate Ihh-PTHrP feedback loop; Altered chondrocyte proliferation and differentiation
PRKAR1A Activation-Resistant PKA Holoenzymes -> End-Organ Hormone Resistance INDIRECT KNOWN INTERMEDIATES Attenuated receptor-triggered PKA activation blunts hormone-responsive transcription in endocrine target tissues. Intermediates: Blunted GPCR-cAMP-PKA signal decoding; Reduced hormone-responsive transcription
Show evidence (1 reference)
PMID:42104421 SUPPORT Other
"activation-resistant RIα holoenzymes impose a dominant-negative constraint by retaining catalytic subunits"
The integrated mechanistic review supports the canonical dominant-negative signal-decoding model.
PDE4D overactivation model
pde4d_overactivation ALTERNATIVE Type 2
Evidence balance 1 support
Some acrodysostosis-associated PDE4D variants are more readily activated by PKA phosphorylation, increasing cAMP hydrolysis and reducing local cAMP-PKA signaling.
Pathograph links
PDE4D Overactivation Hypothesis -> Compartmentalized cAMP-PKA Signal Dysregulation DIRECT Increased PDE4D activation and cAMP hydrolysis can reduce signaling within PDE4D-controlled microdomains.
Compartmentalized cAMP-PKA Signal Dysregulation -> Skeletal Chondrocyte and Endochondral Ossification Dysfunction INDIRECT UNKNOWN INTERMEDIATES PDE4D-associated cAMP microdomain dysregulation perturbs skeletal development, but the human tissue intermediates remain unresolved.
Compartmentalized cAMP-PKA Signal Dysregulation -> Neurodevelopmental Dysfunction INDIRECT UNKNOWN INTERMEDIATES Disturbed PDE4D-controlled signaling is associated with neurodevelopmental impairment, but the causal cellular route is unresolved.
Show evidence (1 reference)
PMID:29016851 SUPPORT In Vitro
"PDE4D3s carrying the ACRDYS2 mutations are more easily activated by protein kinase A-induced phosphorylation than WT PDE4D3."
Functional assays directly support increased activation of four tested mutant PDE4D3 proteins.
PDE4D loss-of-activity with compensatory PDE induction model
pde4d_overcompensation ALTERNATIVE Type 2
Evidence balance 1 support
Other tested PDE4D variants reduce PDE4D activity, while compensatory induction of PDE4A and PDE4B lowers cellular cAMP and pCREB signaling.
Pathograph links
PDE4D Loss-of-Activity with Compensatory PDE Induction Hypothesis -> Compartmentalized cAMP-PKA Signal Dysregulation INDIRECT KNOWN INTERMEDIATES Compensatory PDE4A and PDE4B induction can overcorrect the initial PDE4D deficit and lower cAMP signaling. Intermediates: Compensatory induction of PDE4A and PDE4B isoforms; Reduced cAMP accumulation and pCREB signaling
Compartmentalized cAMP-PKA Signal Dysregulation -> Skeletal Chondrocyte and Endochondral Ossification Dysfunction INDIRECT UNKNOWN INTERMEDIATES PDE4D-associated cAMP microdomain dysregulation perturbs skeletal development, but the human tissue intermediates remain unresolved.
Compartmentalized cAMP-PKA Signal Dysregulation -> Neurodevelopmental Dysfunction INDIRECT UNKNOWN INTERMEDIATES Disturbed PDE4D-controlled signaling is associated with neurodevelopmental impairment, but the causal cellular route is unresolved.
Show evidence (1 reference)
PMID:25064455 SUPPORT In Vitro
"The reason for this discrepancy was due to a compensatory increase in expression levels of PDE4A and PDE4B isoforms, which accounted for the paradoxical decrease in cAMP levels in the patient cells expressing mutant isoforms with a lowered PDE4D activity."
Patient-cell experiments support a compensatory mechanism after reduced activity of two tested PDE4D variants.
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Discussions and Knowledge Gaps

2
Do disease-causing PDE4D variants primarily overactivate PDE4D, reduce its intrinsic activity with compensatory induction of other PDEs, or produce variant- and tissue-specific combinations of both mechanisms?
CONTROVERSY UNDER DISCUSSION pde4d_direction_and_microdomain_controversy
Attached to
pathophysiology#PDE4D Overactivation Hypothesis pathophysiology#PDE4D Loss-of-Activity with Compensatory PDE Induction Hypothesis pathophysiology#Compartmentalized cAMP-PKA Signal Dysregulation
Resolving direction, localization, and variant dependence is necessary before predicting whether a PDE4 inhibitor or another cAMP-directed intervention would normalize or worsen signaling in a given tissue.
Show evidence (3 references)
PMID:38983619 SUPPORT Other
"Two contrasting mechanisms have been proposed to explain how mutations in PDE4D cause iPPSD5."
The 2024 review explicitly frames the unresolved directional controversy.
PMID:29016851 SUPPORT In Vitro
"result in increased hydrolytic activity."
One primary functional study supports the overactivation side.
PMID:25064455 SUPPORT In Vitro
"Our results indicated diminished enzyme activity in the two mutants we analyzed"
A second primary functional study supports reduced mutant activity with compensation.
What are genotype-stratified adult outcomes, untreated growth trajectories, and the prospective benefits and risks of rhGH in acrodysostosis?
KNOWLEDGE GAP OPEN long_term_natural_history_and_growth_treatment
Attached to
phenotypes#Short Stature treatments#Recombinant Human Growth Hormone Therapy
Existing growth evidence is retrospective, final-height samples are very small, and adult skeletal, endocrine, neurologic, and quality-of-life outcomes are incompletely characterized.
Show evidence (1 reference)
PMID:36749450 SUPPORT Human Clinical
"Severe short stature is a feature of acrodysostosis, but data on growth are sparse."
The largest growth study explicitly identifies sparse natural-history data.
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Pathophysiology

7
PRKAR1A Activation-Resistant PKA Holoenzymes
Disease-associated RIα variants impair cAMP binding and the conformational transitions needed to release PKA catalytic subunits. Mutant RIα is expressed and incorporated into holoenzymes, producing attenuated and delayed type I PKA responses.
PRKAR1A activation-resistant PKA signal-decoding model
PRKAR1A hgnc:9388 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves PRKAR1A (hgnc:9388). hgnc:9388 is a gene from the HUGO Gene Nomenclature Committee.
cAMP/PKA signal transduction GO:0141156 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased cAMP/PKA signal transduction (GO:0141156). GO:0141156 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Skeletal Chondrocyte and Endochondral Ossification Dysfunction Impaired RIα-dependent PKA decoding disrupts growth-plate signaling and chondrocyte maturation. PRKAR1A activation-resistant PKA signal-decoding model
End-Organ Hormone Resistance Attenuated receptor-triggered PKA activation blunts hormone-responsive transcription in endocrine target tissues. PRKAR1A activation-resistant PKA signal-decoding model
Show evidence (2 references)
PMID:27825928 SUPPORT In Vitro
"ACRDYS1 mutations result in decreased PKA activity and cAMP resistant holoenzymes."
Structural and biochemical experiments directly demonstrate deficient cAMP-dependent PKA activation.
PMID:42104421 SUPPORT Other
"These variants impair cAMP binding and disrupt the structural transitions needed to disinhibit catalytic subunits."
The mechanistic synthesis supports defective cAMP binding and catalytic-subunit release.
PDE4D Overactivation Hypothesis
In one experimental model, four acrodysostosis-associated PDE4D3 variants were more readily activated by PKA phosphorylation and showed increased hydrolytic activity. This is one of two competing directional models.
PDE4D overactivation model
PDE4D hgnc:8783 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves PDE4D (hgnc:8783). hgnc:8783 is a gene from the HUGO Gene Nomenclature Committee.
cAMP/PKA signal transduction GO:0141156 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased cAMP/PKA signal transduction (GO:0141156). GO:0141156 is a biological process from the Gene Ontology. ↓ DECREASED
3',5'-cyclic-AMP phosphodiesterase activity GO:0004115 Gene Ontology (GO) Relation: this pathophysiological event involves this molecular function This pathophysiological event involves increased 3',5'-cyclic-AMP phosphodiesterase activity (GO:0004115). GO:0004115 is a molecular function from the Gene Ontology. ↑ INCREASED
Downstream
Compartmentalized cAMP-PKA Signal Dysregulation Increased PDE4D activation and cAMP hydrolysis can reduce signaling within PDE4D-controlled microdomains. PDE4D overactivation model
Show evidence (1 reference)
PMID:29016851 SUPPORT In Vitro
"This occurs over a wide range of intracellular cAMP concentrations, including basal conditions, and result in increased hydrolytic activity."
The study directly demonstrates increased hydrolytic activity for its tested PDE4D3 variants.
PDE4D Loss-of-Activity with Compensatory PDE Induction Hypothesis
A second experimental model found diminished activity in two PDE4D variants, followed in patient cells by compensatory PDE4A and PDE4B induction, paradoxically low cAMP accumulation, and reduced pCREB signaling.
PDE4D loss-of-activity with compensatory PDE induction model
PDE4D hgnc:8783 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves PDE4D (hgnc:8783). hgnc:8783 is a gene from the HUGO Gene Nomenclature Committee.
cAMP/PKA signal transduction GO:0141156 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves dysregulated cAMP/PKA signal transduction (GO:0141156). GO:0141156 is a biological process from the Gene Ontology. ↕ DYSREGULATED
3',5'-cyclic-AMP phosphodiesterase activity GO:0004115 Gene Ontology (GO) Relation: this pathophysiological event involves this molecular function This pathophysiological event involves decreased 3',5'-cyclic-AMP phosphodiesterase activity (GO:0004115). GO:0004115 is a molecular function from the Gene Ontology. ↓ DECREASED
Downstream
Compartmentalized cAMP-PKA Signal Dysregulation Compensatory PDE4A and PDE4B induction can overcorrect the initial PDE4D deficit and lower cAMP signaling. PDE4D loss-of-activity with compensatory PDE induction model
Show evidence (1 reference)
PMID:25064455 SUPPORT In Vitro
"Our results indicated diminished enzyme activity in the two mutants we analyzed"
The functional study supports reduced activity for two tested PDE4D variants.
Compartmentalized cAMP-PKA Signal Dysregulation
PDE4D variants disturb the magnitude, timing, and localization of cAMP-PKA signaling. Published functional studies disagree on the initial direction of PDE4D activity, so the shared downstream microdomain defect is retained without selecting either directional hypothesis.
PDE4D loss-of-activity with compensatory PDE induction model PDE4D overactivation model
PDE4D hgnc:8783 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves PDE4D (hgnc:8783). hgnc:8783 is a gene from the HUGO Gene Nomenclature Committee.
cAMP/PKA signal transduction GO:0141156 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves dysregulated cAMP/PKA signal transduction (GO:0141156). GO:0141156 is a biological process from the Gene Ontology. ↕ DYSREGULATED
Downstream
Skeletal Chondrocyte and Endochondral Ossification Dysfunction PDE4D-associated cAMP microdomain dysregulation perturbs skeletal development, but the human tissue intermediates remain unresolved. PDE4D overactivation model PDE4D loss-of-activity with compensatory PDE induction model
Neurodevelopmental Dysfunction Disturbed PDE4D-controlled signaling is associated with neurodevelopmental impairment, but the causal cellular route is unresolved. PDE4D overactivation model PDE4D loss-of-activity with compensatory PDE induction model
Show evidence (1 reference)
PMID:38983619 SUPPORT Other
"Two contrasting mechanisms have been proposed to explain how mutations in PDE4D cause iPPSD5."
The review explicitly establishes unresolved, opposing directional mechanisms.
Skeletal Chondrocyte and Endochondral Ossification Dysfunction
Abnormal cAMP-PKA signaling disrupts chondrocyte proliferation, differentiation, growth-plate architecture, and endochondral bone growth. Type 1 has direct model-organism support; the corresponding type 2 tissue-level bridge is less completely resolved.
chondrocyte CL:0000138 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves chondrocyte (CL:0000138). CL:0000138 is a cell type from the Cell Ontology.
chondrocyte differentiation GO:0002062 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves abnormal chondrocyte differentiation (GO:0002062). GO:0002062 is a biological process from the Gene Ontology. ⚠ ABNORMAL endochondral bone growth GO:0003416 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves abnormal endochondral bone growth (GO:0003416). GO:0003416 is a biological process from the Gene Ontology. ⚠ ABNORMAL
Downstream
Brachydactyly Abnormal acral endochondral growth shortens the metacarpals, metatarsals, and phalanges.
Phalangeal Cone-Shaped Epiphyses Disordered epiphyseal maturation produces the characteristic cone shape.
Short Stature Impaired endochondral bone growth reduces longitudinal growth and final height.
Accelerated Skeletal Maturation Dysregulated epiphyseal development produces advanced bone age and early maturation.
Midface Hypoplasia Craniofacial cartilage and bone growth disturbances contribute to midface retrusion.
Nasal Hypoplasia Craniofacial skeletal dysostosis produces a short, hypoplastic nose.
Show evidence (2 references)
PMID:27589370 SUPPORT Model Organism
"a decrease in the height of terminal hypertrophic chondrocyte layer, an increase in the height of columnar proliferative prehypertrophic chondrocyte layer"
The knock-in model directly demonstrates altered growth-plate chondrocyte architecture.
PMID:34599290 SUPPORT Model Organism
"Chondrocyte architecture was restored in the growth plates."
Preclinical rAAV9-mediated PRKAR1A rescue reverses the growth-plate defect in the knock-in mouse, strengthening causal attribution without implying clinical efficacy.
End-Organ Hormone Resistance
Blunted cAMP-PKA responses in endocrine target tissues produce resistance most consistently to PTH and TSH in PRKAR1A-related type 1. Rare mild resistance has been reported in PDE4D-related type 2, but no canonical PDE4D causal edge is asserted.
cAMP/PKA signal transduction GO:0141156 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased cAMP/PKA signal transduction (GO:0141156). GO:0141156 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Hormone Resistance End-organ failure to transduce PTH and TSH signals manifests clinically and biochemically as hormone resistance.
Hypocalcemia Renal PTH resistance can produce low circulating calcium, although calcium can remain normal in some affected individuals.
Hypothyroidism TSH resistance can reduce thyroid-hormone output, ranging from compensated biochemical resistance to hypothyroidism.
Show evidence (2 references)
PMID:23043190 SUPPORT Human Clinical
"All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH."
The molecular cohort establishes strong PRKAR1A-associated PTH and TSH resistance.
PMID:28515031 SUPPORT Human Clinical
"Laboratory investigations revealed mild thyrotropin resistance."
A familial PDE4D case shows that mild hormone resistance can occur in type 2.
Neurodevelopmental Dysfunction
PDE4D-related acrodysostosis frequently includes intellectual disability, developmental delay, and behavioral differences. The affected neuronal cAMP microdomains and downstream developmental programs are not yet resolved.
nervous system development GO:0007399 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves abnormal nervous system development (GO:0007399). GO:0007399 is a biological process from the Gene Ontology. ⚠ ABNORMAL
Downstream
Intellectual Disability PDE4D-related neurodevelopmental dysfunction manifests as variable intellectual disability.
Global Developmental Delay Motor, speech, and broader developmental delays occur in PDE4D-related disease.
Show evidence (1 reference)
PMID:30006632 SUPPORT Human Clinical
"some degree of intellectual disability."
All PDE4D-positive individuals in this cohort had some degree of intellectual disability.
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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Acrodysostosis Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

13
Endocrine 1
Hypothyroidism HP:0000821 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypothyroidism (HP:0000821). HP:0000821 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:42104421 SUPPORT Other
"elevated TSH concentrations coexist with normal or mildly reduced thyroid hormone levels"
The type 1 review supports hypothyroidism as a variable downstream manifestation of TSH resistance.
Head and Neck 2
Midface Hypoplasia Midface retrusion HP:0011800 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Midface hypoplasia, annotated with Midface retrusion (HP:0011800). HP:0011800 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:30006632 SUPPORT Human Clinical
"All patients with PDE4D variants shared characteristic facial features (midface hypoplasia with nasal hypoplasia)"
The cohort supports the characteristic type 2 midface phenotype without making it exclusive to that subtype.
Nasal Hypoplasia Short nose HP:0003196 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Nasal hypoplasia, annotated with Short nose (HP:0003196). HP:0003196 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"severe brachydactyly, facial dysostosis and nasal hypoplasia."
Nasal hypoplasia is included in the defining consensus triad.
Limbs 1
Brachydactyly HP:0001156 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Brachydactyly (HP:0001156). HP:0001156 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"severe brachydactyly, facial dysostosis and nasal hypoplasia."
Severe brachydactyly is part of the consensus clinical definition.
Metabolism 1
Hypocalcemia HP:0002901 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypocalcemia (HP:0002901). HP:0002901 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:42104421 SUPPORT Other
"elevated circulating PTH concentrations together with normal or low serum calcium and phosphate levels"
The type 1 review documents low calcium as one variable biochemical manifestation of renal PTH resistance.
Musculoskeletal 1
Accelerated Skeletal Maturation HP:0005616 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Accelerated skeletal maturation (HP:0005616). HP:0005616 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"bone age is advanced"
Advanced bone age supports accelerated skeletal maturation.
Nervous System 2
Intellectual Disability HP:0001249 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Intellectual disability (HP:0001249). HP:0001249 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:30006632 SUPPORT Human Clinical
"All patients with PDE4D variants shared characteristic facial features (midface hypoplasia with nasal hypoplasia) and some degree of intellectual disability."
The genotype-stratified cohort supports prominent intellectual involvement in type 2.
PMID:42104421 SUPPORT Other
"Neurodevelopmental and cognitive features have been reported in a subset of individuals with ACRDYS1, but penetrance is variable and manifestations are generally milder than those affecting skeletal or endocrine tissues [7,8,10]."
The type 1 review supports variable, generally milder neurodevelopmental involvement in a subset of PRKAR1A-related cases.
Global Developmental Delay HP:0001263 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Global developmental delay (HP:0001263). HP:0001263 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:28515031 SUPPORT Human Clinical
"A 3.5-year-old boy presented with short stature, midfacial hypoplasia, severe brachydactyly, developmental delay, and behavioural problems."
The PDE4D family report directly supports developmental delay.
Growth 3
Short Stature HP:0004322 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Short stature (HP:0004322). HP:0004322 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:36749450 SUPPORT Human Clinical
"Severe short stature is a feature of acrodysostosis, but data on growth are sparse."
The multicenter growth cohort confirms severe short stature.
Small for Gestational Age HP:0001518 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Small for gestational age (HP:0001518). HP:0001518 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"most patients with acrodysostosis and a muta- tion in PRKAR1A or PDE4D are born SGA"
The international consensus identifies small-for-gestational-age birth in most patients across both gene-defined subtypes.
Obesity HP:0001513 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Obesity (HP:0001513). HP:0001513 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"overweight and obesity are associated with specific PHP- related disorders, such as PHP1A, PHP1C and acrodysosto - sis"
The consensus identifies obesity as an associated acrodysostosis phenotype and lists it in both subtype columns.
Other 2
Phalangeal Cone-Shaped Epiphyses HP:0034281 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Phalangeal cone-shaped epiphyses (HP:0034281). HP:0034281 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"On radiographs, epiphyses display a cone shape"
The consensus directly supports the characteristic epiphyseal morphology.
Hormone Resistance Abnormality of the endocrine system HP:0000818 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Abnormality of the endocrine system (HP:0000818). HP:0000818 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:23043190 SUPPORT Human Clinical
"All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH."
This cohort establishes the strong genotype-phenotype difference.
PMID:28515031 SUPPORT Human Clinical
"Patient 1 had mild TSH resistance, whereas his mother had normal thyroid functions tests at presentation."
Variable expression within one PDE4D family documents a rare type 2 exception.
🧬

Genetic Associations

2
💊

Medical Actions

6
Recombinant Human Growth Hormone Therapy
Category: Therapeutic Action: human growth hormone replacement therapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is human growth hormone replacement therapy, annotated with Hormone Replacement Therapy (NCIT:C15599). NCIT:C15599 is a clinical intervention from the NCI Thesaurus. Ontology label: Hormone Replacement Therapy NCIT:C15599
rhGH is used selectively for severe growth impairment or documented growth hormone deficiency. Retrospective cohort data suggest possible improvement in final height, but the small, nonrandomized evidence base does not establish routine efficacy.
Target Phenotypes: Short Stature HP:0004322 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Short Stature (HP:0004322). HP:0004322 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:36749450 SUPPORT Human Clinical
"Final height may be positively influenced by rhGH in patients with acrodysostosis/iPPSD."
A small retrospective cohort suggests benefit but uses appropriately cautious language.
PMID:42449097 SUPPORT Human Clinical
"After 18 months of rhGH therapy, height increased from 89 cm to 103.5 cm and height SDS improved from - 2.92 to - 1.52"
A single 2026 case supplies limited corroboration in a child with documented partial growth hormone deficiency.
Levothyroxine for Documented Hypothyroidism
Category: Therapeutic Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: levothyroxine CHEBI:18332 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses levothyroxine, annotated with L-thyroxine (CHEBI:18332). CHEBI:18332 is a therapeutic agent from Chemical Entities of Biological Interest.
When TSH resistance produces clinical or biochemical hypothyroidism, levothyroxine indications, dosing, and treatment goals follow standard hypothyroidism practice. Treatment should be based on documented thyroid status rather than genotype alone.
Target Phenotypes: Hypothyroidism HP:0000821 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Hypothyroidism (HP:0000821). HP:0000821 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"The indication or indications to treat hypothyroid- ism, the dosage of levothyroxine and the therapeu- tic goals should be the same as for any patient with hypothyroidism or subclinical hypothyroidism"
The consensus directly states that treatment indications, levothyroxine dosing, and therapeutic goals follow ordinary hypothyroidism practice.
Active Vitamin D and Calcium for PTH Resistance
Category: Therapeutic Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: calcitriol CHEBI:17823 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses calcitriol (CHEBI:17823). CHEBI:17823 is a therapeutic agent from Chemical Entities of Biological Interest. alfacalcidol CHEBI:31186 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses alfacalcidol (CHEBI:31186). CHEBI:31186 is a therapeutic agent from Chemical Entities of Biological Interest. calcium CHEBI:29108 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses calcium, annotated with calcium(2+) (CHEBI:29108). CHEBI:29108 is a therapeutic agent from Chemical Entities of Biological Interest.
Chronic hypocalcemia from PTH resistance is managed with an active vitamin D metabolite or analogue, with oral calcium added as required and laboratory monitoring used to avoid under- or overtreatment.
Target Phenotypes: Hypocalcemia HP:0002901 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Hypocalcemia (HP:0002901). HP:0002901 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"the use of active vitamin D metabolites (calcitriol) or analogues (alfacalcidol) and oral calcium supplements as and when required"
The consensus directly supports active vitamin D with calcium as needed for chronic PTH-resistance hypocalcemia.
Orthopedic and Fine-Motor Support
Category: Therapeutic Action: supportive careNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is supportive care (NCIT:C15747). NCIT:C15747 is a clinical intervention from the NCI Thesaurus. Ontology label: Supportive Care NCIT:C15747
Orthopedic referral, functional assessment, occupational therapy, and adaptive devices are individualized to deformity, impaired hand function, or neurologic symptoms. Additional imaging is symptom-driven rather than automatically scheduled for every patient.
Target Phenotypes: Brachydactyly HP:0001156 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Brachydactyly (HP:0001156). HP:0001156 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:29959430 SUPPORT Other
"Patients with severe brachydactyly should receive formal evaluation of their fine motor skills"
The consensus directly recommends formal functional evaluation for severe brachydactyly.
PMID:29959430 SUPPORT Other
"investigations should be reserved for patients with specific clinical suspicion"
The consensus supports symptom- and function-triggered orthopedic imaging.
Neurodevelopmental and Educational Support
Category: Therapeutic Action: supportive careNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is supportive care (NCIT:C15747). NCIT:C15747 is a clinical intervention from the NCI Thesaurus. Ontology label: Supportive Care NCIT:C15747
Neuropsychological assessment, early developmental services, school-based support, and individualized therapies are guided by the patient's cognitive, behavioral, speech, and motor profile, with particular attention to PDE4D-related type 2.
Target Phenotypes: Intellectual Disability HP:0001249 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Intellectual Disability (HP:0001249). HP:0001249 is a phenotype from the Human Phenotype Ontology. Global Developmental Delay HP:0001263 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Global Developmental Delay (HP:0001263). HP:0001263 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"Additional testing and support as required should also be considered"
The consensus recommends additional testing and support after neurocognitive assessment.
Genetic Counseling
Category: Counseling / Informational Action: Genetic CounselingNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Genetic Counseling (NCIT:C15240). NCIT:C15240 is a clinical intervention from the NCI Thesaurus. NCIT:C15240
Counseling addresses the autosomal dominant mechanism, the predominance of de novo variants, rare inherited PDE4D disease, variable expressivity, recurrence risk, and reproductive options.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"Families can be directed to appropriate support groups, and genetic counselling can be offered."
The consensus directly supports genetic counseling and referral to support resources.
🔬

Biochemical Markers

2
Elevated Parathyroid Hormone (INCREASED)
Context: PTH resistance; interpret with serum calcium and phosphorus
Pathograph Readouts
Readout Of End-Organ Hormone Resistance Positive Diagnostic
Elevated PTH in the appropriate mineral context reports end-organ PTH resistance.
Show evidence (1 reference)
PMID:23043190 SUPPORT Human Clinical
"All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH."
Genotype-stratified endocrine testing supports PTH resistance as a type 1 readout.
Show evidence (1 reference)
PMID:42104421 SUPPORT Other
"Specifically, individuals with ACRDYS1 exhibit elevated circulating PTH concentrations together with normal or low serum calcium and phosphate levels, a pattern that reflects renal PTH resistance in which hormone-induced cAMP generation is intact but fails to activate downstream PKA-dependent..."
The review directly states the characteristic elevated-PTH biochemical pattern and its interpretation as renal PTH resistance.
Elevated Thyroid-Stimulating Hormone (INCREASED)
Context: TSH resistance; interpret with free thyroxine and thyroid autoantibodies
Pathograph Readouts
Readout Of End-Organ Hormone Resistance Positive Diagnostic
Elevated TSH with an appropriate thyroid evaluation reports end-organ TSH resistance.
Show evidence (1 reference)
PMID:23043190 SUPPORT Human Clinical
"All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH."
Genotype-stratified testing supports TSH resistance as a type 1 readout.
Show evidence (1 reference)
PMID:42104421 SUPPORT Other
"A similar pattern is observed in the thyroid axis, where elevated TSH concentrations coexist with normal or mildly reduced thyroid hormone levels [7,8]."
The review directly states the characteristic elevated-TSH biochemical pattern in type 1 disease.
🔬

Diagnosis

3
Clinicoradiologic Evaluation
Severe generalized brachydactyly, facial dysostosis with nasal hypoplasia, short stature, cone-shaped epiphyses, and advanced bone age establish the characteristic clinicoradiologic pattern.
radiograph imaging procedure NCIT:C38101 NCI Thesaurus (NCIT)
Show evidence (2 references)
PMID:29959430 SUPPORT Other
"severe brachydactyly, facial dysostosis and nasal hypoplasia."
The consensus defines the characteristic clinical triad.
PMID:29959430 SUPPORT Other
"On radiographs, epiphyses display a cone shape, bone age is advanced"
The consensus supplies the characteristic radiographic findings.
Endocrine Laboratory Assessment
At diagnosis, assess calcium, phosphorus, PTH, thyroid-stimulating hormone, and free thyroxine; thyroid autoantibodies help distinguish coincident autoimmune disease. Follow-up frequency should reflect genotype and findings.
endocrine testing NCIT:C74971 NCI Thesaurus (NCIT)
Show evidence (2 references)
PMID:29959430 SUPPORT Other
"we recommend the monitoring of serum levels of PTH, calcium, phosphorus and calcifediol."
The consensus directly recommends the PTH and mineral panel.
PMID:29959430 SUPPORT Other
"at diagnosis. Thereafter, TSH monitoring is recommended every 6 months"
The consensus supports thyroid-function evaluation at diagnosis and continued monitoring.
Molecular Confirmation and Subtyping
Molecular genetic testing of PRKAR1A and PDE4D confirms the diagnosis and assigns type 1 or type 2. Broader testing is appropriate when the phenotype overlaps another iPPSD or skeletal-dysplasia disorder.
molecular genetic testing NCIT:C19770 NCI Thesaurus (NCIT)
Show evidence (2 references)
PMID:29959430 SUPPORT Other
"clinical and laboratory diagnosis should be confirmed by a molecular genetic analysis."
The international consensus explicitly recommends molecular confirmation.
PMID:23043190 SUPPORT Human Clinical
"Acrodysostosis is genetically heterogeneous because it results from heterozygous mutations in PRKAR1A or PDE4D"
Molecular testing must cover both established gene-defined subtypes.
🩻

Imaging Findings

2
Cone-Shaped Phalangeal Epiphyses on Radiographs
Hand and foot radiographs show cone-shaped epiphyses with generalized acral shortening.
Xray Diagnostic
Phalangeal cone-shaped epiphyses HP:0034281 Human Phenotype Ontology (HP) Phalangeal cone-shaped epiphyses HP:0034281 Human Phenotype Ontology (HP)
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"On radiographs, epiphyses display a cone shape"
The consensus directly supports this diagnostic radiographic finding.
Advanced Bone Age on Radiographs
Bone age is often advanced, with early epiphyseal maturation or fusion.
Xray
Accelerated skeletal maturation HP:0005616 Human Phenotype Ontology (HP) Accelerated skeletal maturation HP:0005616 Human Phenotype Ontology (HP)
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"bone age is advanced"
The consensus explicitly supports advanced bone age.
📈

Progression

2
Congenital or early skeletal presentation
Age: Birth to early childhood
Characteristic skeletal abnormalities may be present at birth or emerge soon afterward; advanced bone age can become evident on radiographs.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"bone age is advanced and abnormalities might be present at birth or soon thereafter."
The consensus describes congenital or early radiographic onset and advanced skeletal maturation.
Postnatal growth
Age: Childhood through attainment of final height
Postnatal linear growth is impaired and often culminates in severe short stature. Longitudinal growth and adult-outcome data remain sparse.
Show evidence (1 reference)
PMID:36749450 SUPPORT Human Clinical
"Severe short stature is a feature of acrodysostosis, but data on growth are sparse."
The largest growth cohort identifies severe short stature while emphasizing limited natural-history data.
📊

Prevalence

1
Worldwide
Unknown Unknown
The disease is uncommon, but no population prevalence estimate is available. Published case counts should not be interpreted as prevalence.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"Acrodysostosis is uncommon; the prevalence of the disease is unknown"
The international consensus explicitly states that acrodysostosis prevalence is unknown.
🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Acrodysostosis:

Pseudohypoparathyroidism Type 1A Not Yet Curated MONDO:0007078
Overlapping Features Maternal GNAS-related iPPSD2 can combine PTH and TSH resistance with brachydactyly, short stature, and neurocognitive involvement. Subcutaneous ossifications, obesity, and the Albright hereditary osteodystrophy pattern favor PHP1A; marked nasal hypoplasia and cone-shaped epiphyses favor acrodysostosis.
Distinguishing Features
  • GNAS-related disease rather than PRKAR1A- or PDE4D-related disease.
  • Albright hereditary osteodystrophy includes subcutaneous ossifications, round face, short stature, brachydactyly, and a stocky build.
  • Generalized severe brachydactyly with cone-shaped epiphyses and nasal hypoplasia favors acrodysostosis.
Show evidence (1 reference)
PMID:29280743 SUPPORT Other
"Albright hereditary osteodystrophy (AHO) is described as an associated clinical entity with PHP, characterized by brachydactyly, subcutaneous ossifications, round face, short stature and a stocky build."
The review supports the overlapping AHO pattern and the features that distinguish PHP1A.
2q37 Microdeletion Syndrome MONDO:0010886
Overlapping Features The HDAC4-containing 2q37 deletion syndrome overlaps through brachydactyly, short stature, obesity, and neurodevelopmental impairment. Demonstration of a pathogenic 2q37 deletion by chromosomal testing establishes the alternative diagnosis.
Distinguishing Features
  • A pathogenic 2q37 deletion rather than a heterozygous PRKAR1A or PDE4D variant.
  • Obesity and psychomotor or cognitive alterations occur with brachydactyly and short stature.
Show evidence (1 reference)
PMID:29959430 SUPPORT Other
"short stature, brachydactyly and psychomotor and cognitive alterations"
The consensus differential table summarizes the overlapping 2q37 phenotype.
Metaphyseal Acroscyphodysplasia Not Yet Curated MONDO:0009592
Overlapping Features This severe PDE4D-associated allelic skeletal dysplasia overlaps through growth retardation and brachydactyly but is distinguished radiographically by knee epiphyses embedded in cup-shaped metaphyses.
Distinguishing Features
  • Cup-shaped metaphyses surrounding the knee epiphyses.
  • Often more severe skeletal involvement than classic acrodysostosis.
  • PDE4D variation can occur in either disorder, so radiographic pattern remains essential.
Show evidence (1 reference)
PMID:30006632 SUPPORT Human Clinical
"Acroscyphodysplasia (MIM 250215) is characterized by growth retardation, brachydactyly, and knee epiphyses embedded in cup-shaped metaphyses."
The cohort directly defines the distinguishing radiographic pattern.
🔬

Clinical Trials

1
NCT01793168 NOT_APPLICABLE RECRUITING
CoRDS is a broad observational rare-disease patient registry and natural history study that explicitly includes an Acrodysostosis Support and Research Registry. It is not an acrodysostosis-specific interventional treatment trial.
Show evidence (3 references)
clinicaltrials:NCT01793168 SUPPORT Human Clinical
"It provides researchers with a centralized, international patient registry for all rare diseases."
The ClinicalTrials.gov summary confirms that NCT01793168 is a broad international registry.
url:https://clinicaltrials.gov/api/v2/studies/NCT01793168 SUPPORT Human Clinical
"1. Acrodysostosis Support and Research Registry"
The raw ClinicalTrials.gov record explicitly lists the acrodysostosis subregistry.
url:https://clinicaltrials.gov/api/v2/studies/NCT01793168 SUPPORT Human Clinical
""overallStatus":"RECRUITING""
The ClinicalTrials.gov API record reports recruiting status.
{ }

Source YAML

click to show 
name: Acrodysostosis
creation_date: "2026-04-16T00:00:00Z"
description: >-
  Acrodysostosis is a skeletal dysplasia characterized by severe brachydactyly,
  cone-shaped epiphyses, midface and nasal hypoplasia, short stature, and
  variable endocrine and neurodevelopmental involvement. Molecularly defined
  disease comprises PRKAR1A-related type 1 (iPPSD4) and PDE4D-related type 2
  (iPPSD5), which disturb cAMP-PKA signaling through distinct mechanisms.
category: Mendelian
parents:
- hereditary disease
- skeletal dysplasia
synonyms:
- acrodysplasie
- Maroteaux-type acrodysostosis
- AHO-like syndrome with severe brachydactyly
disease_term:
  preferred_term: acrodysostosis
  term:
    id: MONDO:0019797
    label: acrodysostosis
has_subtypes:
- name: Type 1
  display_name: Acrodysostosis type 1 (PRKAR1A; iPPSD4)
  subtype_term:
    preferred_term: Acrodysostosis 1 with or without hormone resistance
    term:
      id: MONDO:0007044
      label: Acrodysostosis 1 with or without hormone resistance
  description: >-
    Type 1 is caused by heterozygous PRKAR1A variants that impair cAMP-dependent
    activation of type I PKA. PTH and TSH resistance are characteristic, although
    the overall phenotype remains variable.
  genes:
  - preferred_term: PRKAR1A
    term:
      id: hgnc:9388
      label: PRKAR1A
  evidence:
  - reference: PMID:42104421
    reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "It is caused by heterozygous mutations in PRKAR1A, which encodes the type Iα regulatory subunit (RIα) of protein kinase A (PKA), a central mediator of cyclic AMP (cAMP)-dependent signalling."
    explanation: The 2026 mechanistic review defines the PRKAR1A-related subtype and its affected PKA regulatory subunit.
- name: Type 2
  display_name: Acrodysostosis type 2 (PDE4D; iPPSD5)
  subtype_term:
    preferred_term: acrodysostosis 2 with or without hormone resistance
    term:
      id: MONDO:0013822
      label: acrodysostosis 2 with or without hormone resistance
  description: >-
    Type 2 is caused by heterozygous PDE4D variants. Facial dysostosis and
    neurodevelopmental involvement are often prominent; hormone resistance is
    less typical but has been reported.
  genes:
  - preferred_term: PDE4D
    term:
      id: hgnc:8783
      label: PDE4D
  evidence:
  - reference: PMID:29016851
    reference_title: Mutations causing acrodysostosis-2 facilitate activation of phosphodiesterase 4D3.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Type 2 acrodysostosis (ACRDYS2), a rare developmental skeletal dysplasia characterized by short stature, severe brachydactyly and facial dysostosis, is caused by mutations in the phosphodiesterase (PDE) 4D (PDE4D) gene."
    explanation: The functional study defines PDE4D as the gene responsible for acrodysostosis type 2.
inheritance:
- name: Autosomal dominant
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  description: >-
    Acrodysostosis is autosomal dominant. Most molecularly documented cases are
    sporadic and caused by heterozygous de novo variants, while rare familial
    PDE4D-related pedigrees demonstrate vertical transmission and variable
    expressivity.
  evidence:
  - reference: PMID:23043190
    reference_title: PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All patients had heterozygous de novo mutations."
    explanation: All 16 unrelated individuals in this molecular cohort had heterozygous de novo PRKAR1A or PDE4D variants.
  - reference: PMID:28515031
    reference_title: Phenotypic Variability in a Family with Acrodysostosis Type 2 Caused by a Novel PDE4D Mutation Affecting the Serine Target of Protein Kinase-A Phosphorylation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We report on a rare multigenerational familial case of acrodysostosis type 2 due to a novel autosomal dominantly inherited PDE4D mutation."
    explanation: A multigenerational family confirms autosomal dominant PDE4D transmission and qualifies the predominance of de novo cases.
classifications:
  isds_skeletal_category:
  - classification_value: acromelic_dysplasias
    notes: >-
      ISDS Nosology of Genetic Skeletal Disorders. Assigned from the 2019 revision
      (Mortier et al., PMID:31633310), Table 1 group 15 "Acromelic dysplasias"; listed
      as "Acrodysostosis". Re-verified against the 2023 revision (Unger et al.,
      PMID:36779427), which retains it in the acromelic group - now group 17 - as
      "Acrodysostosis, PRKAR1A-related" and "Acrodysostosis, PDE4D-related". It does NOT
      belong to the new group 28 (parathyroid hormone signaling cascade) despite being
      an inactivating PTH/PTHrP-signalling disorder (iPPSD4): group 28 holds the
      PTH1R/SIK3/PTHLH set. Placement follows the committee's listing, not the
      mechanism.
prevalence:
- population: Worldwide
  measure_type: UNKNOWN
  prevalence_class: UNKNOWN
  notes: >-
    The disease is uncommon, but no population prevalence estimate is available.
    Published case counts should not be interpreted as prevalence.
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Acrodysostosis is uncommon; the prevalence of the disease is unknown"
    explanation: The international consensus explicitly states that acrodysostosis prevalence is unknown.
mechanistic_hypotheses:
- hypothesis_group_id: prkar1a_signal_decoding
  hypothesis_label: PRKAR1A activation-resistant PKA signal-decoding model
  status: CANONICAL
  applies_to_subtypes:
  - Type 1
  description: >-
    Mutant RIα incorporates into type I PKA holoenzymes but responds poorly to
    physiological cAMP, retaining catalytic subunits and imposing a
    dominant-negative constraint on timed PKA activation.
  evidence:
  - reference: PMID:42104421
    reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "activation-resistant RIα holoenzymes impose a dominant-negative constraint by retaining catalytic subunits"
    explanation: The integrated mechanistic review supports the canonical dominant-negative signal-decoding model.
- hypothesis_group_id: pde4d_overactivation
  hypothesis_label: PDE4D overactivation model
  status: ALTERNATIVE
  applies_to_subtypes:
  - Type 2
  description: >-
    Some acrodysostosis-associated PDE4D variants are more readily activated by
    PKA phosphorylation, increasing cAMP hydrolysis and reducing local cAMP-PKA
    signaling.
  evidence:
  - reference: PMID:29016851
    reference_title: Mutations causing acrodysostosis-2 facilitate activation of phosphodiesterase 4D3.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "PDE4D3s carrying the ACRDYS2 mutations are more easily activated by protein kinase A-induced phosphorylation than WT PDE4D3."
    explanation: Functional assays directly support increased activation of four tested mutant PDE4D3 proteins.
- hypothesis_group_id: pde4d_overcompensation
  hypothesis_label: PDE4D loss-of-activity with compensatory PDE induction model
  status: ALTERNATIVE
  applies_to_subtypes:
  - Type 2
  description: >-
    Other tested PDE4D variants reduce PDE4D activity, while compensatory
    induction of PDE4A and PDE4B lowers cellular cAMP and pCREB signaling.
  evidence:
  - reference: PMID:25064455
    reference_title: Heterozygous mutations in cyclic AMP phosphodiesterase-4D (PDE4D) and protein kinase A (PKA) provide new insights into the molecular pathology of acrodysostosis.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "The reason for this discrepancy was due to a compensatory increase in expression levels of PDE4A and PDE4B isoforms, which accounted for the paradoxical decrease in cAMP levels in the patient cells expressing mutant isoforms with a lowered PDE4D activity."
    explanation: Patient-cell experiments support a compensatory mechanism after reduced activity of two tested PDE4D variants.
progression:
- phase: Congenital or early skeletal presentation
  age_range: Birth to early childhood
  notes: >-
    Characteristic skeletal abnormalities may be present at birth or emerge soon
    afterward; advanced bone age can become evident on radiographs.
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "bone age is advanced and abnormalities might be present at birth or soon thereafter."
    explanation: The consensus describes congenital or early radiographic onset and advanced skeletal maturation.
- phase: Postnatal growth
  age_range: Childhood through attainment of final height
  notes: >-
    Postnatal linear growth is impaired and often culminates in severe short
    stature. Longitudinal growth and adult-outcome data remain sparse.
  evidence:
  - reference: PMID:36749450
    reference_title: Growth patterns and outcomes of growth hormone therapy in patients with acrodysostosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Severe short stature is a feature of acrodysostosis, but data on growth are sparse."
    explanation: The largest growth cohort identifies severe short stature while emphasizing limited natural-history data.
pathophysiology:
- name: PRKAR1A Activation-Resistant PKA Holoenzymes
  subtypes:
  - Type 1
  description: >-
    Disease-associated RIα variants impair cAMP binding and the conformational
    transitions needed to release PKA catalytic subunits. Mutant RIα is expressed
    and incorporated into holoenzymes, producing attenuated and delayed type I
    PKA responses.
  genes:
  - preferred_term: PRKAR1A
    term:
      id: hgnc:9388
      label: PRKAR1A
  biological_processes:
  - preferred_term: cAMP/PKA signal transduction
    term:
      id: GO:0141156
      label: cAMP/PKA signal transduction
    modifier: DECREASED
  mechanism_confidence: ESTABLISHED
  evidence:
  - reference: PMID:27825928
    reference_title: Structure of a PKA RIα Recurrent Acrodysostosis Mutant Explains Defective cAMP-Dependent Activation.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "ACRDYS1 mutations result in decreased PKA activity and cAMP resistant holoenzymes."
    explanation: Structural and biochemical experiments directly demonstrate deficient cAMP-dependent PKA activation.
  - reference: PMID:42104421
    reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "These variants impair cAMP binding and disrupt the structural transitions needed to disinhibit catalytic subunits."
    explanation: The mechanistic synthesis supports defective cAMP binding and catalytic-subunit release.
  downstream:
  - target: Skeletal Chondrocyte and Endochondral Ossification Dysfunction
    description: Impaired RIα-dependent PKA decoding disrupts growth-plate signaling and chondrocyte maturation.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Disruption of the growth-plate Ihh-PTHrP feedback loop
    - Altered chondrocyte proliferation and differentiation
    hypothesis_groups:
    - prkar1a_signal_decoding
    evidence:
    - reference: PMID:42104421
      reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Impaired RIα-dependent decoding of cAMP signals disrupts the Ihh-PTHrP feedback loop in the growth plate"
      explanation: This provides the mechanistic bridge from defective PKA signal decoding to growth-plate dysfunction.
  - target: End-Organ Hormone Resistance
    description: Attenuated receptor-triggered PKA activation blunts hormone-responsive transcription in endocrine target tissues.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Blunted GPCR-cAMP-PKA signal decoding
    - Reduced hormone-responsive transcription
    hypothesis_groups:
    - prkar1a_signal_decoding
    evidence:
    - reference: PMID:42104421
      reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "blunts hormone-responsive transcriptional programmes in endocrine epithelia"
      explanation: The review connects impaired RIα signaling to deficient endocrine transcriptional responses.
- name: PDE4D Overactivation Hypothesis
  subtypes:
  - Type 2
  description: >-
    In one experimental model, four acrodysostosis-associated PDE4D3 variants
    were more readily activated by PKA phosphorylation and showed increased
    hydrolytic activity. This is one of two competing directional models.
  genes:
  - preferred_term: PDE4D
    term:
      id: hgnc:8783
      label: PDE4D
  molecular_functions:
  - preferred_term: 3',5'-cyclic-AMP phosphodiesterase activity
    term:
      id: GO:0004115
      label: 3',5'-cyclic-AMP phosphodiesterase activity
    modifier: INCREASED
  biological_processes:
  - preferred_term: cAMP/PKA signal transduction
    term:
      id: GO:0141156
      label: cAMP/PKA signal transduction
    modifier: DECREASED
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: PMID:29016851
    reference_title: Mutations causing acrodysostosis-2 facilitate activation of phosphodiesterase 4D3.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "This occurs over a wide range of intracellular cAMP concentrations, including basal conditions, and result in increased hydrolytic activity."
    explanation: The study directly demonstrates increased hydrolytic activity for its tested PDE4D3 variants.
  downstream:
  - target: Compartmentalized cAMP-PKA Signal Dysregulation
    description: Increased PDE4D activation and cAMP hydrolysis can reduce signaling within PDE4D-controlled microdomains.
    causal_link_type: DIRECT
    hypothesis_groups:
    - pde4d_overactivation
    evidence:
    - reference: PMID:29016851
      reference_title: Mutations causing acrodysostosis-2 facilitate activation of phosphodiesterase 4D3.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "PDE4D3s carrying the ACRDYS2 mutations are more easily activated by protein kinase A-induced phosphorylation than WT PDE4D3."
      explanation: Mutant PDE4D3 activation directly alters control of cAMP microdomains.
- name: PDE4D Loss-of-Activity with Compensatory PDE Induction Hypothesis
  subtypes:
  - Type 2
  description: >-
    A second experimental model found diminished activity in two PDE4D variants,
    followed in patient cells by compensatory PDE4A and PDE4B induction,
    paradoxically low cAMP accumulation, and reduced pCREB signaling.
  genes:
  - preferred_term: PDE4D
    term:
      id: hgnc:8783
      label: PDE4D
  molecular_functions:
  - preferred_term: 3',5'-cyclic-AMP phosphodiesterase activity
    term:
      id: GO:0004115
      label: 3',5'-cyclic-AMP phosphodiesterase activity
    modifier: DECREASED
  biological_processes:
  - preferred_term: cAMP/PKA signal transduction
    term:
      id: GO:0141156
      label: cAMP/PKA signal transduction
    modifier: DYSREGULATED
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: PMID:25064455
    reference_title: Heterozygous mutations in cyclic AMP phosphodiesterase-4D (PDE4D) and protein kinase A (PKA) provide new insights into the molecular pathology of acrodysostosis.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Our results indicated diminished enzyme activity in the two mutants we analyzed"
    explanation: The functional study supports reduced activity for two tested PDE4D variants.
  downstream:
  - target: Compartmentalized cAMP-PKA Signal Dysregulation
    description: Compensatory PDE4A and PDE4B induction can overcorrect the initial PDE4D deficit and lower cAMP signaling.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Compensatory induction of PDE4A and PDE4B isoforms
    - Reduced cAMP accumulation and pCREB signaling
    hypothesis_groups:
    - pde4d_overcompensation
    evidence:
    - reference: PMID:25064455
      reference_title: Heterozygous mutations in cyclic AMP phosphodiesterase-4D (PDE4D) and protein kinase A (PKA) provide new insights into the molecular pathology of acrodysostosis.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "The reason for this discrepancy was due to a compensatory increase in expression levels of PDE4A and PDE4B isoforms"
      explanation: The measured compensatory induction supplies the known intermediate between reduced mutant activity and low cellular cAMP.
- name: Compartmentalized cAMP-PKA Signal Dysregulation
  subtypes:
  - Type 2
  description: >-
    PDE4D variants disturb the magnitude, timing, and localization of cAMP-PKA
    signaling. Published functional studies disagree on the initial direction of
    PDE4D activity, so the shared downstream microdomain defect is retained
    without selecting either directional hypothesis.
  genes:
  - preferred_term: PDE4D
    term:
      id: hgnc:8783
      label: PDE4D
  biological_processes:
  - preferred_term: cAMP/PKA signal transduction
    term:
      id: GO:0141156
      label: cAMP/PKA signal transduction
    modifier: DYSREGULATED
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: PMID:38983619
    reference_title: "Phosphodiesterase 4D activity in acrodysostosis-associated neural pathology: too much or too little?"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Two contrasting mechanisms have been proposed to explain how mutations in PDE4D cause iPPSD5."
    explanation: The review explicitly establishes unresolved, opposing directional mechanisms.
  downstream:
  - target: Skeletal Chondrocyte and Endochondral Ossification Dysfunction
    description: PDE4D-associated cAMP microdomain dysregulation perturbs skeletal development, but the human tissue intermediates remain unresolved.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    hypothesis_groups:
    - pde4d_overactivation
    - pde4d_overcompensation
    evidence:
    - reference: PMID:25064455
      reference_title: Heterozygous mutations in cyclic AMP phosphodiesterase-4D (PDE4D) and protein kinase A (PKA) provide new insights into the molecular pathology of acrodysostosis.
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Skeletal radiographs of 10-week-old knockout (KO) rats showed that the distal part of the forelimb was shorter than in wild-type (WT) rats and that all the metacarpals and phalanges were also shorter in KO, as the name acrodysostosis implies."
      explanation: The knockout-rat skeletal phenotype directly links loss of PDE4D function to distal bone shortening while leaving the tissue-level intermediates incomplete.
  - target: Neurodevelopmental Dysfunction
    description: Disturbed PDE4D-controlled signaling is associated with neurodevelopmental impairment, but the causal cellular route is unresolved.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    hypothesis_groups:
    - pde4d_overactivation
    - pde4d_overcompensation
    evidence:
    - reference: PMID:38983619
      reference_title: "Phosphodiesterase 4D activity in acrodysostosis-associated neural pathology: too much or too little?"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "intellectual disability is seen in ∼90% of patients"
      explanation: The review documents a strong type 2 clinical association while emphasizing that the molecular route remains unsettled.
- name: Skeletal Chondrocyte and Endochondral Ossification Dysfunction
  subtypes:
  - Type 1
  - Type 2
  description: >-
    Abnormal cAMP-PKA signaling disrupts chondrocyte proliferation,
    differentiation, growth-plate architecture, and endochondral bone growth.
    Type 1 has direct model-organism support; the corresponding type 2
    tissue-level bridge is less completely resolved.
  cell_types:
  - preferred_term: chondrocyte
    term:
      id: CL:0000138
      label: chondrocyte
  biological_processes:
  - preferred_term: chondrocyte differentiation
    term:
      id: GO:0002062
      label: chondrocyte differentiation
    modifier: ABNORMAL
  - preferred_term: endochondral bone growth
    term:
      id: GO:0003416
      label: endochondral bone growth
    modifier: ABNORMAL
  mechanism_confidence: ESTABLISHED
  evidence:
  - reference: PMID:27589370
    reference_title: "Knock-In of the Recurrent R368X Mutation of PRKAR1A that Represses cAMP-Dependent Protein Kinase A Activation: A Model of Type 1 Acrodysostosis."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "a decrease in the height of terminal hypertrophic chondrocyte layer, an increase in the height of columnar proliferative prehypertrophic chondrocyte layer"
    explanation: The knock-in model directly demonstrates altered growth-plate chondrocyte architecture.
  - reference: PMID:34599290
    reference_title: Correction of a knock-in mouse model of acrodysostosis with gene therapy using a rAAV9-CAG-human PRKAR1A vector.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Chondrocyte architecture was restored in the growth plates."
    explanation: Preclinical rAAV9-mediated PRKAR1A rescue reverses the growth-plate defect in the knock-in mouse, strengthening causal attribution without implying clinical efficacy.
  downstream:
  - target: Brachydactyly
    description: Abnormal acral endochondral growth shortens the metacarpals, metatarsals, and phalanges.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:27589370
      reference_title: "Knock-In of the Recurrent R368X Mutation of PRKAR1A that Represses cAMP-Dependent Protein Kinase A Activation: A Model of Type 1 Acrodysostosis."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Growth retardation, peripheral acrodysostosis (including brachydactyly affecting all digits), and facial dysostosis were shown"
      explanation: The PRKAR1A knock-in model reproduces brachydactyly as an output of the skeletal developmental defect.
  - target: Phalangeal Cone-Shaped Epiphyses
    description: Disordered epiphyseal maturation produces the characteristic cone shape.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:29959430
      reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "On radiographs, epiphyses display a cone shape"
      explanation: The consensus identifies cone-shaped epiphyses as the characteristic radiographic skeletal output.
  - target: Short Stature
    description: Impaired endochondral bone growth reduces longitudinal growth and final height.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:36749450
      reference_title: Growth patterns and outcomes of growth hormone therapy in patients with acrodysostosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Severe short stature is a feature of acrodysostosis"
      explanation: The growth cohort supports short stature as a direct clinical consequence of the skeletal growth disorder.
  - target: Accelerated Skeletal Maturation
    description: Dysregulated epiphyseal development produces advanced bone age and early maturation.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:29959430
      reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "bone age is advanced"
      explanation: The consensus directly identifies advanced bone age in acrodysostosis.
  - target: Midface Hypoplasia
    description: Craniofacial cartilage and bone growth disturbances contribute to midface retrusion.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:30006632
      reference_title: "Expanding the phenotypic spectrum of variants in PDE4D/PRKAR1A: from acrodysostosis to acroscyphodysplasia."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "All patients with PDE4D variants shared characteristic facial features (midface hypoplasia with nasal hypoplasia)"
      explanation: The cohort establishes the craniofacial phenotype, while the detailed tissue intermediates remain unresolved.
  - target: Nasal Hypoplasia
    description: Craniofacial skeletal dysostosis produces a short, hypoplastic nose.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:29959430
      reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "severe brachydactyly, facial dysostosis and nasal hypoplasia."
      explanation: The consensus includes nasal hypoplasia in the defining clinical triad.
- name: End-Organ Hormone Resistance
  subtypes:
  - Type 1
  description: >-
    Blunted cAMP-PKA responses in endocrine target tissues produce resistance
    most consistently to PTH and TSH in PRKAR1A-related type 1. Rare mild
    resistance has been reported in PDE4D-related type 2, but no canonical PDE4D
    causal edge is asserted.
  biological_processes:
  - preferred_term: cAMP/PKA signal transduction
    term:
      id: GO:0141156
      label: cAMP/PKA signal transduction
    modifier: DECREASED
  mechanism_confidence: ESTABLISHED
  evidence:
  - reference: PMID:23043190
    reference_title: PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH."
    explanation: The molecular cohort establishes strong PRKAR1A-associated PTH and TSH resistance.
  - reference: PMID:28515031
    reference_title: Phenotypic Variability in a Family with Acrodysostosis Type 2 Caused by a Novel PDE4D Mutation Affecting the Serine Target of Protein Kinase-A Phosphorylation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Laboratory investigations revealed mild thyrotropin resistance."
    explanation: A familial PDE4D case shows that mild hormone resistance can occur in type 2.
  downstream:
  - target: Hormone Resistance
    description: End-organ failure to transduce PTH and TSH signals manifests clinically and biochemically as hormone resistance.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:23043190
      reference_title: PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH."
      explanation: Genotype-stratified endocrine testing directly supports the type 1 phenotype edge.
  - target: Hypocalcemia
    description: Renal PTH resistance can produce low circulating calcium, although calcium can remain normal in some affected individuals.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:42104421
      reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "elevated circulating PTH concentrations together with normal or low serum calcium and phosphate levels"
      explanation: The type 1 review supports hypocalcemia as a variable direct biochemical consequence of renal PTH resistance.
  - target: Hypothyroidism
    description: TSH resistance can reduce thyroid-hormone output, ranging from compensated biochemical resistance to hypothyroidism.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:42104421
      reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "elevated TSH concentrations coexist with normal or mildly reduced thyroid hormone levels"
      explanation: The type 1 review supports reduced thyroid-hormone output as a variable direct consequence of TSH resistance.
- name: Neurodevelopmental Dysfunction
  subtypes:
  - Type 2
  description: >-
    PDE4D-related acrodysostosis frequently includes intellectual disability,
    developmental delay, and behavioral differences. The affected neuronal
    cAMP microdomains and downstream developmental programs are not yet resolved.
  biological_processes:
  - preferred_term: nervous system development
    term:
      id: GO:0007399
      label: nervous system development
    modifier: ABNORMAL
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: PMID:30006632
    reference_title: "Expanding the phenotypic spectrum of variants in PDE4D/PRKAR1A: from acrodysostosis to acroscyphodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "some degree of intellectual disability."
    explanation: All PDE4D-positive individuals in this cohort had some degree of intellectual disability.
  downstream:
  - target: Intellectual Disability
    description: PDE4D-related neurodevelopmental dysfunction manifests as variable intellectual disability.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:30006632
      reference_title: "Expanding the phenotypic spectrum of variants in PDE4D/PRKAR1A: from acrodysostosis to acroscyphodysplasia."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "some degree of intellectual disability."
      explanation: The genotype-stratified cohort directly supports intellectual disability in type 2.
  - target: Global Developmental Delay
    description: Motor, speech, and broader developmental delays occur in PDE4D-related disease.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:28515031
      reference_title: Phenotypic Variability in a Family with Acrodysostosis Type 2 Caused by a Novel PDE4D Mutation Affecting the Serine Target of Protein Kinase-A Phosphorylation.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "A 3.5-year-old boy presented with short stature, midfacial hypoplasia, severe brachydactyly, developmental delay, and behavioural problems."
      explanation: The familial type 2 report directly documents developmental delay and behavioral involvement.
phenotypes:
- name: Brachydactyly
  diagnostic: true
  phenotype_term:
    preferred_term: Brachydactyly
    term:
      id: HP:0001156
      label: Brachydactyly
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "severe brachydactyly, facial dysostosis and nasal hypoplasia."
    explanation: Severe brachydactyly is part of the consensus clinical definition.
- name: Phalangeal Cone-Shaped Epiphyses
  diagnostic: true
  phenotype_term:
    preferred_term: Phalangeal cone-shaped epiphyses
    term:
      id: HP:0034281
      label: Phalangeal cone-shaped epiphyses
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "On radiographs, epiphyses display a cone shape"
    explanation: The consensus directly supports the characteristic epiphyseal morphology.
- name: Midface Hypoplasia
  subtypes:
  - Type 1
  - Type 2
  diagnostic: true
  description: >-
    Midface retrusion occurs across the spectrum and is particularly
    characteristic in many PDE4D-related cases.
  phenotype_term:
    preferred_term: Midface hypoplasia
    term:
      id: HP:0011800
      label: Midface retrusion
  evidence:
  - reference: PMID:30006632
    reference_title: "Expanding the phenotypic spectrum of variants in PDE4D/PRKAR1A: from acrodysostosis to acroscyphodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All patients with PDE4D variants shared characteristic facial features (midface hypoplasia with nasal hypoplasia)"
    explanation: The cohort supports the characteristic type 2 midface phenotype without making it exclusive to that subtype.
- name: Nasal Hypoplasia
  subtypes:
  - Type 1
  - Type 2
  diagnostic: true
  phenotype_term:
    preferred_term: Nasal hypoplasia
    term:
      id: HP:0003196
      label: Short nose
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "severe brachydactyly, facial dysostosis and nasal hypoplasia."
    explanation: Nasal hypoplasia is included in the defining consensus triad.
- name: Short Stature
  diagnostic: true
  phenotype_term:
    preferred_term: Short stature
    term:
      id: HP:0004322
      label: Short stature
  evidence:
  - reference: PMID:36749450
    reference_title: Growth patterns and outcomes of growth hormone therapy in patients with acrodysostosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Severe short stature is a feature of acrodysostosis, but data on growth are sparse."
    explanation: The multicenter growth cohort confirms severe short stature.
- name: Small for Gestational Age
  subtypes:
  - Type 1
  - Type 2
  diagnostic: false
  description: >-
    Prenatal growth restriction is common across both molecular subtypes, but
    subtype-stratified birth-size distributions remain incompletely defined.
  phenotype_term:
    preferred_term: Small for gestational age
    term:
      id: HP:0001518
      label: Small for gestational age
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "most patients with acrodysostosis and a muta- tion in PRKAR1A or PDE4D are born SGA"
    explanation: The international consensus identifies small-for-gestational-age birth in most patients across both gene-defined subtypes.
- name: Obesity
  subtypes:
  - Type 1
  - Type 2
  diagnostic: false
  description: >-
    Overweight and obesity occur in both molecular subtypes, although robust
    subtype-specific frequencies and longitudinal metabolic outcomes are not
    available.
  phenotype_term:
    preferred_term: Obesity
    term:
      id: HP:0001513
      label: Obesity
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "overweight and obesity are associated with specific PHP- related disorders, such as PHP1A, PHP1C and acrodysosto - sis"
    explanation: The consensus identifies obesity as an associated acrodysostosis phenotype and lists it in both subtype columns.
- name: Accelerated Skeletal Maturation
  diagnostic: false
  phenotype_term:
    preferred_term: Accelerated skeletal maturation
    term:
      id: HP:0005616
      label: Accelerated skeletal maturation
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "bone age is advanced"
    explanation: Advanced bone age supports accelerated skeletal maturation.
- name: Hormone Resistance
  subtypes:
  - Type 1
  - Type 2
  diagnostic: false
  description: >-
    PTH and TSH resistance are characteristic of PRKAR1A-related type 1.
    PDE4D-related type 2 usually lacks marked resistance, but rare mild or
    clinically significant endocrine abnormalities have been reported.
  phenotype_term:
    preferred_term: Abnormality of the endocrine system
    term:
      id: HP:0000818
      label: Abnormality of the endocrine system
  evidence:
  - reference: PMID:23043190
    reference_title: PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH."
    explanation: This cohort establishes the strong genotype-phenotype difference.
  - reference: PMID:28515031
    reference_title: Phenotypic Variability in a Family with Acrodysostosis Type 2 Caused by a Novel PDE4D Mutation Affecting the Serine Target of Protein Kinase-A Phosphorylation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patient 1 had mild TSH resistance, whereas his mother had normal thyroid functions tests at presentation."
    explanation: Variable expression within one PDE4D family documents a rare type 2 exception.
- name: Hypocalcemia
  subtype: Type 1
  diagnostic: false
  description: >-
    Renal PTH resistance can lower serum calcium in PRKAR1A-related disease,
    although calcium may remain normal and the finding is not obligatory.
  phenotype_term:
    preferred_term: Hypocalcemia
    term:
      id: HP:0002901
      label: Hypocalcemia
  evidence:
  - reference: PMID:42104421
    reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "elevated circulating PTH concentrations together with normal or low serum calcium and phosphate levels"
    explanation: The type 1 review documents low calcium as one variable biochemical manifestation of renal PTH resistance.
- name: Hypothyroidism
  subtype: Type 1
  diagnostic: false
  description: >-
    TSH resistance may progress from compensated TSH elevation to mildly
    reduced thyroid-hormone levels and clinically documented hypothyroidism.
  phenotype_term:
    preferred_term: Hypothyroidism
    term:
      id: HP:0000821
      label: Hypothyroidism
  evidence:
  - reference: PMID:42104421
    reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "elevated TSH concentrations coexist with normal or mildly reduced thyroid hormone levels"
    explanation: The type 1 review supports hypothyroidism as a variable downstream manifestation of TSH resistance.
- name: Intellectual Disability
  subtypes:
  - Type 1
  - Type 2
  diagnostic: false
  description: >-
    Intellectual disability is variable across acrodysostosis and is especially
    prominent in PDE4D-related type 2; it is not treated as subtype-exclusive.
  phenotype_term:
    preferred_term: Intellectual disability
    term:
      id: HP:0001249
      label: Intellectual disability
  evidence:
  - reference: PMID:30006632
    reference_title: "Expanding the phenotypic spectrum of variants in PDE4D/PRKAR1A: from acrodysostosis to acroscyphodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All patients with PDE4D variants shared characteristic facial features (midface hypoplasia with nasal hypoplasia) and some degree of intellectual disability."
    explanation: The genotype-stratified cohort supports prominent intellectual involvement in type 2.
  - reference: PMID:42104421
    reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Neurodevelopmental and cognitive features have been reported in a subset of individuals with ACRDYS1, but penetrance is variable and manifestations are generally milder than those affecting skeletal or endocrine tissues [7,8,10]."
    explanation: The type 1 review supports variable, generally milder neurodevelopmental involvement in a subset of PRKAR1A-related cases.
- name: Global Developmental Delay
  subtype: Type 2
  diagnostic: false
  phenotype_term:
    preferred_term: Global developmental delay
    term:
      id: HP:0001263
      label: Global developmental delay
  evidence:
  - reference: PMID:28515031
    reference_title: Phenotypic Variability in a Family with Acrodysostosis Type 2 Caused by a Novel PDE4D Mutation Affecting the Serine Target of Protein Kinase-A Phosphorylation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A 3.5-year-old boy presented with short stature, midfacial hypoplasia, severe brachydactyly, developmental delay, and behavioural problems."
    explanation: The PDE4D family report directly supports developmental delay.
imaging_findings:
- name: Cone-Shaped Phalangeal Epiphyses on Radiographs
  modality: XRAY
  imaging_finding_term:
    preferred_term: Phalangeal cone-shaped epiphyses
    term:
      id: HP:0034281
      label: Phalangeal cone-shaped epiphyses
  phenotype_term:
    preferred_term: Phalangeal cone-shaped epiphyses
    term:
      id: HP:0034281
      label: Phalangeal cone-shaped epiphyses
  diagnostic: true
  description: Hand and foot radiographs show cone-shaped epiphyses with generalized acral shortening.
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "On radiographs, epiphyses display a cone shape"
    explanation: The consensus directly supports this diagnostic radiographic finding.
- name: Advanced Bone Age on Radiographs
  modality: XRAY
  imaging_finding_term:
    preferred_term: Accelerated skeletal maturation
    term:
      id: HP:0005616
      label: Accelerated skeletal maturation
  phenotype_term:
    preferred_term: Accelerated skeletal maturation
    term:
      id: HP:0005616
      label: Accelerated skeletal maturation
  diagnostic: false
  description: Bone age is often advanced, with early epiphyseal maturation or fusion.
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "bone age is advanced"
    explanation: The consensus explicitly supports advanced bone age.
biochemical:
- name: Elevated Parathyroid Hormone
  subtype: Type 1
  presence: INCREASED
  context: PTH resistance; interpret with serum calcium and phosphorus
  biomarker_term:
    preferred_term: Elevated circulating parathyroid hormone level
    term:
      id: HP:0003165
      label: Elevated circulating parathyroid hormone level
  readouts:
  - target: End-Organ Hormone Resistance
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: Elevated PTH in the appropriate mineral context reports end-organ PTH resistance.
    evidence:
    - reference: PMID:23043190
      reference_title: PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH."
      explanation: Genotype-stratified endocrine testing supports PTH resistance as a type 1 readout.
  evidence:
  - reference: PMID:42104421
    reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Specifically, individuals with ACRDYS1 exhibit elevated circulating PTH concentrations together with normal or low serum calcium and phosphate levels, a pattern that reflects renal PTH resistance in which hormone-induced cAMP generation is intact but fails to activate downstream PKA-dependent effector pathways [7,8]."
    explanation: The review directly states the characteristic elevated-PTH biochemical pattern and its interpretation as renal PTH resistance.
- name: Elevated Thyroid-Stimulating Hormone
  subtype: Type 1
  presence: INCREASED
  context: TSH resistance; interpret with free thyroxine and thyroid autoantibodies
  biomarker_term:
    preferred_term: Elevated circulating thyroid-stimulating hormone concentration
    term:
      id: HP:0002925
      label: Elevated circulating thyroid-stimulating hormone concentration
  readouts:
  - target: End-Organ Hormone Resistance
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: Elevated TSH with an appropriate thyroid evaluation reports end-organ TSH resistance.
    evidence:
    - reference: PMID:23043190
      reference_title: PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "All PRKAR1A, but none of the PDE4D mutated patients were resistant to PTH and TSH."
      explanation: Genotype-stratified testing supports TSH resistance as a type 1 readout.
  evidence:
  - reference: PMID:42104421
    reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "A similar pattern is observed in the thyroid axis, where elevated TSH concentrations coexist with normal or mildly reduced thyroid hormone levels [7,8]."
    explanation: The review directly states the characteristic elevated-TSH biochemical pattern in type 1 disease.
genetic:
- name: PRKAR1A-Related Acrodysostosis Type 1
  subtype: Type 1
  gene_term:
    preferred_term: PRKAR1A
    term:
      id: hgnc:9388
      label: PRKAR1A
  association: Heterozygous pathogenic variants impair cAMP-dependent activation of type I PKA.
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:23043190
    reference_title: PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acrodysostosis is genetically heterogeneous because it results from heterozygous mutations in PRKAR1A or PDE4D"
    explanation: A genotype-stratified cohort establishes heterozygous PRKAR1A variants as causative.
  - reference: PMID:42104421
    reference_title: "Acrodysostosis type 1: mechanisms explaining PRKAR1A mutation mediated dysregulation of cAMP-PKA signalling."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "It is caused by heterozygous mutations in PRKAR1A"
    explanation: The mechanistic review directly identifies heterozygous PRKAR1A variation as the type 1 cause.
- name: PDE4D-Related Acrodysostosis Type 2
  subtype: Type 2
  gene_term:
    preferred_term: PDE4D
    term:
      id: hgnc:8783
      label: PDE4D
  association: Heterozygous pathogenic variants dysregulate compartmentalized cAMP hydrolysis and PKA signaling.
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:23043190
    reference_title: PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acrodysostosis is genetically heterogeneous because it results from heterozygous mutations in PRKAR1A or PDE4D"
    explanation: The cohort establishes PDE4D as the second causative acrodysostosis gene.
  - reference: PMID:28515031
    reference_title: Phenotypic Variability in a Family with Acrodysostosis Type 2 Caused by a Novel PDE4D Mutation Affecting the Serine Target of Protein Kinase-A Phosphorylation.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Genetic analysis identified the identical, novel heterozygous missense mutation of the PDE4D gene c.569C>T (p.Ser190Phe) in both patients."
    explanation: A familial heterozygous PDE4D variant segregated with variably expressed type 2 disease.
diagnosis:
- name: Clinicoradiologic Evaluation
  description: >-
    Severe generalized brachydactyly, facial dysostosis with nasal hypoplasia,
    short stature, cone-shaped epiphyses, and advanced bone age establish the
    characteristic clinicoradiologic pattern.
  diagnosis_term:
    preferred_term: radiograph imaging procedure
    term:
      id: NCIT:C38101
      label: X-Ray Imaging
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "severe brachydactyly, facial dysostosis and nasal hypoplasia."
    explanation: The consensus defines the characteristic clinical triad.
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "On radiographs, epiphyses display a cone shape, bone age is advanced"
    explanation: The consensus supplies the characteristic radiographic findings.
- name: Endocrine Laboratory Assessment
  description: >-
    At diagnosis, assess calcium, phosphorus, PTH, thyroid-stimulating hormone,
    and free thyroxine; thyroid autoantibodies help distinguish coincident
    autoimmune disease. Follow-up frequency should reflect genotype and findings.
  diagnosis_term:
    preferred_term: endocrine testing
    term:
      id: NCIT:C74971
      label: Endocrine Test
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "we recommend the monitoring of serum levels of PTH, calcium, phosphorus and calcifediol."
    explanation: The consensus directly recommends the PTH and mineral panel.
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "at diagnosis. Thereafter, TSH monitoring is recommended every 6 months"
    explanation: The consensus supports thyroid-function evaluation at diagnosis and continued monitoring.
- name: Molecular Confirmation and Subtyping
  description: >-
    Molecular genetic testing of PRKAR1A and PDE4D confirms the diagnosis and
    assigns type 1 or type 2. Broader testing is appropriate when the phenotype
    overlaps another iPPSD or skeletal-dysplasia disorder.
  diagnosis_term:
    preferred_term: molecular genetic testing
    term:
      id: NCIT:C19770
      label: Molecular Analysis
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "clinical and laboratory diagnosis should be confirmed by a molecular genetic analysis."
    explanation: The international consensus explicitly recommends molecular confirmation.
  - reference: PMID:23043190
    reference_title: PRKAR1A and PDE4D mutations cause acrodysostosis but two distinct syndromes with or without GPCR-signaling hormone resistance.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acrodysostosis is genetically heterogeneous because it results from heterozygous mutations in PRKAR1A or PDE4D"
    explanation: Molecular testing must cover both established gene-defined subtypes.
differential_diagnoses:
- name: Pseudohypoparathyroidism Type 1A
  disease_term:
    preferred_term: pseudohypoparathyroidism type 1A
    term:
      id: MONDO:0007078
      label: pseudohypoparathyroidism type 1A
  description: >-
    Maternal GNAS-related iPPSD2 can combine PTH and TSH resistance with
    brachydactyly, short stature, and neurocognitive involvement. Subcutaneous
    ossifications, obesity, and the Albright hereditary osteodystrophy pattern
    favor PHP1A; marked nasal hypoplasia and cone-shaped epiphyses favor
    acrodysostosis.
  distinguishing_features:
  - GNAS-related disease rather than PRKAR1A- or PDE4D-related disease.
  - Albright hereditary osteodystrophy includes subcutaneous ossifications, round face, short stature, brachydactyly, and a stocky build.
  - Generalized severe brachydactyly with cone-shaped epiphyses and nasal hypoplasia favors acrodysostosis.
  evidence:
  - reference: PMID:29280743
    reference_title: "Current Nomenclature of Pseudohypoparathyroidism: Inactivating Parathyroid Hormone/Parathyroid Hormone-Related Protein Signaling Disorder."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Albright hereditary osteodystrophy (AHO) is described as an associated clinical entity with PHP, characterized by brachydactyly, subcutaneous ossifications, round face, short stature and a stocky build."
    explanation: The review supports the overlapping AHO pattern and the features that distinguish PHP1A.
- name: 2q37 Microdeletion Syndrome
  disease_term:
    preferred_term: 2q37 microdeletion syndrome
    term:
      id: MONDO:0010886
      label: 2q37 microdeletion syndrome
  description: >-
    The HDAC4-containing 2q37 deletion syndrome overlaps through
    brachydactyly, short stature, obesity, and neurodevelopmental impairment.
    Demonstration of a pathogenic 2q37 deletion by chromosomal testing
    establishes the alternative diagnosis.
  distinguishing_features:
  - A pathogenic 2q37 deletion rather than a heterozygous PRKAR1A or PDE4D variant.
  - Obesity and psychomotor or cognitive alterations occur with brachydactyly and short stature.
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "short stature, brachydactyly and psychomotor and cognitive alterations"
    explanation: The consensus differential table summarizes the overlapping 2q37 phenotype.
- name: Metaphyseal Acroscyphodysplasia
  disease_term:
    preferred_term: metaphyseal acroscyphodysplasia
    term:
      id: MONDO:0009592
      label: metaphyseal acroscyphodysplasia
  description: >-
    This severe PDE4D-associated allelic skeletal dysplasia overlaps through
    growth retardation and brachydactyly but is distinguished radiographically
    by knee epiphyses embedded in cup-shaped metaphyses.
  distinguishing_features:
  - Cup-shaped metaphyses surrounding the knee epiphyses.
  - Often more severe skeletal involvement than classic acrodysostosis.
  - PDE4D variation can occur in either disorder, so radiographic pattern remains essential.
  evidence:
  - reference: PMID:30006632
    reference_title: "Expanding the phenotypic spectrum of variants in PDE4D/PRKAR1A: from acrodysostosis to acroscyphodysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acroscyphodysplasia (MIM 250215) is characterized by growth retardation, brachydactyly, and knee epiphyses embedded in cup-shaped metaphyses."
    explanation: The cohort directly defines the distinguishing radiographic pattern.
clinical_trials:
- name: NCT01793168
  phase: NOT_APPLICABLE
  status: RECRUITING
  description: >-
    CoRDS is a broad observational rare-disease patient registry and natural
    history study that explicitly includes an Acrodysostosis Support and
    Research Registry. It is not an acrodysostosis-specific interventional
    treatment trial.
  evidence:
  - reference: clinicaltrials:NCT01793168
    reference_title: Coordination of Rare Diseases at Sanford
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It provides researchers with a centralized, international patient registry for all rare diseases."
    explanation: The ClinicalTrials.gov summary confirms that NCT01793168 is a broad international registry.
  - reference: url:https://clinicaltrials.gov/api/v2/studies/NCT01793168
    reference_title: "https://clinicaltrials.gov/api/v2/studies/NCT01793168"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "1. Acrodysostosis Support and Research Registry"
    explanation: The raw ClinicalTrials.gov record explicitly lists the acrodysostosis subregistry.
  - reference: url:https://clinicaltrials.gov/api/v2/studies/NCT01793168
    reference_title: "https://clinicaltrials.gov/api/v2/studies/NCT01793168"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: '"overallStatus":"RECRUITING"'
    explanation: The ClinicalTrials.gov API record reports recruiting status.
datasets: []
treatments:
- name: Recombinant Human Growth Hormone Therapy
  action_category: THERAPEUTIC
  description: >-
    rhGH is used selectively for severe growth impairment or documented growth
    hormone deficiency. Retrospective cohort data suggest possible improvement
    in final height, but the small, nonrandomized evidence base does not
    establish routine efficacy.
  treatment_term:
    preferred_term: human growth hormone replacement therapy
    term:
      id: NCIT:C15599
      label: Hormone Replacement Therapy
  target_phenotypes:
  - preferred_term: Short Stature
    term:
      id: HP:0004322
      label: Short stature
  evidence:
  - reference: PMID:36749450
    reference_title: Growth patterns and outcomes of growth hormone therapy in patients with acrodysostosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Final height may be positively influenced by rhGH in patients with acrodysostosis/iPPSD."
    explanation: A small retrospective cohort suggests benefit but uses appropriately cautious language.
  - reference: PMID:42449097
    reference_title: "PRKAR1A-related acrodysostosis with partial growth hormone deficiency: 18-month response to recombinant human growth hormone."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "After 18 months of rhGH therapy, height increased from 89 cm to 103.5 cm and height SDS improved from - 2.92 to - 1.52"
    explanation: A single 2026 case supplies limited corroboration in a child with documented partial growth hormone deficiency.
- name: Levothyroxine for Documented Hypothyroidism
  action_category: THERAPEUTIC
  description: >-
    When TSH resistance produces clinical or biochemical hypothyroidism,
    levothyroxine indications, dosing, and treatment goals follow standard
    hypothyroidism practice. Treatment should be based on documented thyroid
    status rather than genotype alone.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: levothyroxine
      term:
        id: CHEBI:18332
        label: L-thyroxine
  target_phenotypes:
  - preferred_term: Hypothyroidism
    term:
      id: HP:0000821
      label: Hypothyroidism
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The indication or indications to treat hypothyroid- ism, the dosage of levothyroxine and the therapeu- tic goals should be the same as for any patient with hypothyroidism or subclinical hypothyroidism"
    explanation: The consensus directly states that treatment indications, levothyroxine dosing, and therapeutic goals follow ordinary hypothyroidism practice.
- name: Active Vitamin D and Calcium for PTH Resistance
  action_category: THERAPEUTIC
  description: >-
    Chronic hypocalcemia from PTH resistance is managed with an active vitamin D
    metabolite or analogue, with oral calcium added as required and laboratory
    monitoring used to avoid under- or overtreatment.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: calcitriol
      term:
        id: CHEBI:17823
        label: calcitriol
    - preferred_term: alfacalcidol
      term:
        id: CHEBI:31186
        label: alfacalcidol
    - preferred_term: calcium
      term:
        id: CHEBI:29108
        label: calcium(2+)
  target_phenotypes:
  - preferred_term: Hypocalcemia
    term:
      id: HP:0002901
      label: Hypocalcemia
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "the use of active vitamin D metabolites (calcitriol) or analogues (alfacalcidol) and oral calcium supplements as and when required"
    explanation: The consensus directly supports active vitamin D with calcium as needed for chronic PTH-resistance hypocalcemia.
- name: Orthopedic and Fine-Motor Support
  action_category: THERAPEUTIC
  description: >-
    Orthopedic referral, functional assessment, occupational therapy, and
    adaptive devices are individualized to deformity, impaired hand function, or
    neurologic symptoms. Additional imaging is symptom-driven rather than
    automatically scheduled for every patient.
  treatment_term:
    preferred_term: supportive care
    term:
      id: NCIT:C15747
      label: Supportive Care
  target_phenotypes:
  - preferred_term: Brachydactyly
    term:
      id: HP:0001156
      label: Brachydactyly
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Patients with severe brachydactyly should receive formal evaluation of their fine motor skills"
    explanation: The consensus directly recommends formal functional evaluation for severe brachydactyly.
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "investigations should be reserved for patients with specific clinical suspicion"
    explanation: The consensus supports symptom- and function-triggered orthopedic imaging.
- name: Neurodevelopmental and Educational Support
  action_category: THERAPEUTIC
  description: >-
    Neuropsychological assessment, early developmental services, school-based
    support, and individualized therapies are guided by the patient's cognitive,
    behavioral, speech, and motor profile, with particular attention to
    PDE4D-related type 2.
  treatment_term:
    preferred_term: supportive care
    term:
      id: NCIT:C15747
      label: Supportive Care
  target_phenotypes:
  - preferred_term: Intellectual Disability
    term:
      id: HP:0001249
      label: Intellectual disability
  - preferred_term: Global Developmental Delay
    term:
      id: HP:0001263
      label: Global developmental delay
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Additional testing and support as required should also be considered"
    explanation: The consensus recommends additional testing and support after neurocognitive assessment.
- name: Genetic Counseling
  action_category: COUNSELING_INFORMATIONAL
  description: >-
    Counseling addresses the autosomal dominant mechanism, the predominance of
    de novo variants, rare inherited PDE4D disease, variable expressivity,
    recurrence risk, and reproductive options.
  treatment_term:
    preferred_term: Genetic Counseling
    term:
      id: NCIT:C15240
      label: Genetic Counseling
  evidence:
  - reference: PMID:29959430
    reference_title: "Diagnosis and management of pseudohypoparathyroidism and related disorders: first international Consensus Statement."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Families can be directed to appropriate support groups, and genetic counselling can be offered."
    explanation: The consensus directly supports genetic counseling and referral to support resources.
discussions:
- discussion_id: pde4d_direction_and_microdomain_controversy
  prompt: >-
    Do disease-causing PDE4D variants primarily overactivate PDE4D, reduce its
    intrinsic activity with compensatory induction of other PDEs, or produce
    variant- and tissue-specific combinations of both mechanisms?
  kind: CONTROVERSY
  status: UNDER_DISCUSSION
  attaches_to:
  - pathophysiology#PDE4D Overactivation Hypothesis
  - pathophysiology#PDE4D Loss-of-Activity with Compensatory PDE Induction Hypothesis
  - pathophysiology#Compartmentalized cAMP-PKA Signal Dysregulation
  rationale: >-
    Resolving direction, localization, and variant dependence is necessary
    before predicting whether a PDE4 inhibitor or another cAMP-directed
    intervention would normalize or worsen signaling in a given tissue.
  evidence:
  - reference: PMID:38983619
    reference_title: "Phosphodiesterase 4D activity in acrodysostosis-associated neural pathology: too much or too little?"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Two contrasting mechanisms have been proposed to explain how mutations in PDE4D cause iPPSD5."
    explanation: The 2024 review explicitly frames the unresolved directional controversy.
  - reference: PMID:29016851
    reference_title: Mutations causing acrodysostosis-2 facilitate activation of phosphodiesterase 4D3.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "result in increased hydrolytic activity."
    explanation: One primary functional study supports the overactivation side.
  - reference: PMID:25064455
    reference_title: Heterozygous mutations in cyclic AMP phosphodiesterase-4D (PDE4D) and protein kinase A (PKA) provide new insights into the molecular pathology of acrodysostosis.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Our results indicated diminished enzyme activity in the two mutants we analyzed"
    explanation: A second primary functional study supports reduced mutant activity with compensation.
- discussion_id: long_term_natural_history_and_growth_treatment
  prompt: >-
    What are genotype-stratified adult outcomes, untreated growth trajectories,
    and the prospective benefits and risks of rhGH in acrodysostosis?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - phenotypes#Short Stature
  - treatments#Recombinant Human Growth Hormone Therapy
  rationale: >-
    Existing growth evidence is retrospective, final-height samples are very
    small, and adult skeletal, endocrine, neurologic, and quality-of-life
    outcomes are incompletely characterized.
  evidence:
  - reference: PMID:36749450
    reference_title: Growth patterns and outcomes of growth hormone therapy in patients with acrodysostosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Severe short stature is a feature of acrodysostosis, but data on growth are sparse."
    explanation: The largest growth study explicitly identifies sparse natural-history data.
📚

References & Deep Research

Deep Research

1
Asta ▸
Asta Literature Retrieval: Pathophysiology and clinical mechanisms of Acrodysostosis. Core disease mechanisms, molecular and cellular pathways,...
Asta Scientific Corpus Retrieval 20 citations 2026-04-16T14:41:26.646602

Asta Literature Retrieval: Pathophysiology and clinical mechanisms of Acrodysostosis. Core disease mechanisms, molecular and cellular pathways,...

This report is retrieval-only and is generated directly from Asta results.

  • Papers retrieved: 20
  • Snippets retrieved: 20

Relevant Papers

[1] New therapeutic targets in rare genetic skeletal diseases

  • Authors: M. Briggs, Peter A. Bell, M. Wright, K. A. Pirog
  • Year: 2015
  • Venue: Expert Opinion on Orphan Drugs
  • URL: https://www.semanticscholar.org/paper/1363107f71ae6d2d60abca471cddf3da5d13644b
  • DOI: 10.1517/21678707.2015.1083853
  • PMID: 26635999
  • PMCID: 4643203
  • Citations: 37
  • Influential citations: 1
  • Summary: An overview of disease mechanisms that are shared amongst groups of different GSDs and potential therapeutic approaches that are under investigation are described to generate critical mass for the identification and validation of novel therapeutic targets and biomarkers.
  • Evidence snippets:
  • Snippet 1 (score: 0.433) > proteins of the cartilage ECM such as type II collagen [50]. However, emerging knowledge suggests that the primary genetic defect may be less important than the cells' response to the expression of the mutant gene product [107]. Moreover, the largely overlooked response of a cell (i.e. chondrocyte) to the abnormal extracellular environment is also important for disease progression as illustrated by several GSDs discussed in this review. > It is important that 'omics'-based approaches and technologies are systematically applied to the study of rare GSDs so that definitive reference profiles and disease signatures are generated for each phenotype. These can then be used in a Systems Biology approach to identify both common and dissimilar pathological signatures and disease mechanisms. This approach is entirely dependent upon relevant in vitro and in vivo models (and also novel 'disease-mechanism phenocopies' [107]) for testing new diagnostic and prognostic tools and for determining the molecular mechanisms that underpin the pathophysiology so that effective therapeutic treatments can be developed and validated. This approach will eventually lead to personalized treatments and care strategies centred on shared disease mechanisms with the use of relevant biomarkers to monitor the efficacy of treatment and disease progression. > It is vital that all relevant stakeholders are involved from the outset in defining the appropriate outcomes of any potential therapeutic regime. The perceptions of a successful therapy can differ widely between the clinical academic community and the relevant patient-support groups and it is vital that there is engagement on all these issues. > In summary, the identification of causative genes and mutations for GSDs over the last 20 years, coupled with the generation and in-depth analysis of a plethora of relevant cell and mouse models, has derived new knowledge on disease mechanisms and suggested potential therapeutic targets. The fast-evolving hypothesis that clinically disparate diseases can share common disease mechanisms is a powerful concept that will generate critical mass for the identification and validation of novel therapeutic targets and biomarkers.

[2] Changes in Serum Proteomic Profiles at Different Stages of Pregnancy Toxemia in Goats

  • Authors: M. Uzti̇mür, C. N. Ünal, Gurler Akpinar
  • Year: 2025
  • Venue: Journal of Veterinary Internal Medicine
  • URL: https://www.semanticscholar.org/paper/4b9c488b5dbd65d7b26fd2ad9aed70e8c4b59942
  • DOI: 10.1111/jvim.70139
  • PMID: 40492724
  • PMCID: 12150350
  • Summary: Understanding the serum proteome profiles of goats with pregnancy toxemia might help identify the proteomes and pathways responsible for the development of this disease and improve diagnosis and treatment.
  • Evidence snippets:
  • Snippet 1 (score: 0.392) > The pathophysiology and progression of this disease are not fully understood. > Traditional biomedical research has focused on the analysis of single genes, proteins, metabolites, or metabolic pathways in diseases. This molecular reductionist approach is based on the assumption that identifying genetic variations and molecular components will lead to new treatments for diseases [13][14][15][16]. However, many diseases are complex and multifactorial, and in order to determine the phenotype of such diseases, it is necessary to understand the changes that occur in more than one gene, pathway, protein, or metabolite at the cellular, tissue, and organismal levels [17][18][19]. Therefore, in recent years, proteomics, as one field of multi-omics technologies, has helped in evaluating the complex pathogenetic mechanisms of different diseases from a broad perspective and has made substantial contributions [20,21]. In veterinary medicine, proteomic analysis of metabolic diseases such as ketosis [16], hypocalcemia [22], and fatty liver [23] in dairy cows has contributed valuable insights for the definition of new pathophysiological pathways and new diagnosis and treatment protocols for these diseases. The proteomic approach can contribute importantly to a broad and detailed understanding of the changes that occur at the organismal level associated with the increase in BHBA concentration in goats with pregnancy toxemia. Our aim was to evaluate the serum protein profiles of goats with SPT or CPT using proteomic techniques to determine the proteomic profiles of these animals and to identify the relevant pathophysiological mechanisms.

[3] Molecular Mechanisms and Risk Factors for the Pathogenesis of Hydrocephalus

  • Authors: Jing-wen Li, Xinjie Zhang, Jianfeng Guo, Chen Yu, Jun Yang
  • Year: 2022
  • Venue: Frontiers in Genetics
  • URL: https://www.semanticscholar.org/paper/d53bdf5f73f54a6d5a8be8777d23c465a13e9185
  • DOI: 10.3389/fgene.2021.777926
  • PMID: 35047005
  • PMCID: 8762052
  • Citations: 15
  • Influential citations: 2
  • Summary: Some possible fundamental molecular mechanisms and facilitating risk factors involved in the pathogenesis of hydrocephalus are elicited, and knowledge could be used to improve patient care in different ways, such as early precise diagnosis and effective therapeutic regimens.
  • Evidence snippets:
  • Snippet 1 (score: 0.383) > Cwh43 modifies the glycosylphosphatidylinositol-anchored proteins on the ependymal cells, and the mutant Cwh43 is related to iNPH in both humans and mice. The clinical features manifest as late-onset communicating hydrocephalus with symptoms of gait and balance dysfunction (Yang et al., 2021a). > The clinical manifestation and progression, as well as experimental investigations, indicate that hydrocephalus is a complex disease with polygenic involvement, rather than a simple CSF accumulation disorder. Although the current studies have revealed that some genetic mutations are involved in the pathogenesis of hydrocephalus, how these mutations are associated with the disorder of CSF circulation and their pathogenic roles in the pathological progression of hydrocephalus still remain largely unknown. Previous studies indicated that a lot of genetic mutations were relevant to the disorders of ciliary and/or centrosome, resulting in the dysfunction of the glymphatic system. However, how these mutations and their interactions contribute to the pathogenesis of hydrocephalus needs to be further elucidated. Moreover, there is still a lack of basic knowledge on the mechanisms underlying the cognitive functional impairment of hydrocephalus. Therefore, further extensive studies should be conducted to explore the underlying molecular mechanisms of identified and/or unidentified genes in the pathophysiology of hydrocephalus. Based on our knowledge, we propose that the genetic mutations relevant to ciliary and centrosomal proteins and the interaction between glymphatic system and ciliary/ centrosomal structures/functions may be a critical molecular mechanism in the pathophysiology of hydrocephalus. In addition, based on these fundamental molecular mechanisms, it is noteworthy that environmental and other acquired risks or etiological factors are also involved in the facilitation of ventricular enlargement.

[4] Organoids in gastrointestinal diseases: from bench to clinic

  • Authors: Qinying Wang, Fanying Guo, Qinyuan Zhang, Tingting Hu, Yutao Jin et al.
  • Year: 2024
  • Venue: MedComm
  • URL: https://www.semanticscholar.org/paper/9b8880d8b9d45670da950197d7e353794f51d09e
  • DOI: 10.1002/mco2.574
  • PMID: 38948115
  • PMCID: 11214594
  • Citations: 12
  • Summary: A comprehensive and systematical depiction of organoids models is drawn, providing a novel insight into the utilization of organoids models from bench to clinic and clinical adhibition.
  • Evidence snippets:
  • Snippet 1 (score: 0.381) > Organoids models offer a robust platform for investigating the potential mechanisms of GI diseases and evaluating potential therapeutic interventions.By culturing organoids derived from patients' tissues or stem cells, researchers can delve into disease-specific cellular and molecular pathways, encompassing aberrant cell signaling, perturbed immune responses, and dysfunctional metabolic processes.These disease-specific phenotypes enable the study of disease progression, screening of prospective therapeutics, as well as identification of novel drug targets and mechanisms of action for GI diseases in a clinically relevant context.

[5] A Roadmap to Gene Discoveries and Novel Therapies in Monogenic Low and High Bone Mass Disorders

  • Authors: M. Formosa, D. Bergen, C. Gregson, A. Maurizi, A. Kämpe et al.
  • Year: 2021
  • Venue: Frontiers in Endocrinology
  • URL: https://www.semanticscholar.org/paper/be13ff3ea01dc5719f2c63b2cbf5d9f77bafd659
  • DOI: 10.3389/fendo.2021.709711
  • PMID: 34539568
  • PMCID: 8444146
  • Citations: 21
  • Summary: The monogenic forms of rare low and high rare bone Mass disorders known to date are described, a roadmap to unravel the genetic determinants of monogenic rare bone mass disorders is provided, using proper phenotyping and genotyping methods are provided, and different genetic validation approaches paving the way for future treatments are described.
  • Evidence snippets:
  • Snippet 1 (score: 0.379) > Skeletal development is regulated by numerous genetic factors that guide the growth, modeling and remodeling of skeletal structures starting in early fetal development and continuing throughout life. These processes are crucial for attainment of normal height, skeletal patterning, bone shape, and mobility, but also for maintenance of normal bone mass and fracture resistance. Defects in the involved genes result in a large and heterogeneous group of disorders, collectively called skeletal dysplasias, in which the primary features are confined to the skeleton. More than 460 different forms of skeletal dysplasia, most of them monogenic, have been recognized (1). They are estimated to affect approximately 1/5,000 children (2,3), and can have distinct clinical manifestations and course. Clinical outcomes range in severity from neonatal lethality to only mild growth retardation, deformity or fracture risk. Diagnosis is based on growth pattern and other clinical characteristics, skeletal imaging, bone density testing, biochemical diagnostics, and genetic tests. Although the genetic basis has been described and mutations in the responsible genes identified in a significant proportion of these conditions, for several distinct skeletal dysplasia phenotypes the genetic cause is still not known (1). > Within this large group of genetic skeletal disorders, monogenic disorders affecting bone mass comprise an expanding subgroup (1,4). This includes disorders with low bone mass and skeletal fragility, and disorders leading to increased bone mass, both commonly associated with extraskeletal complications (5,6). Due to significant variability in severity, diagnosis can be challenging. Importantly, the underlying molecular genetic mechanisms for these disorders remain inadequately explored and, in several entities, the causative genetic defect, and underlying cellular and molecular pathophysiology are still uncharacterized. > The various skeletal dysplasia delineated to date have provided important information about the molecular pathways governing skeletal health both in these conditions and in the general population, underscoring the significance of new gene discoveries not only for the individuals affected by the monogenic rare bone mass disorder, but also more widely to the musculoskeletal research field (7). Indeed, the large wealth of data generated from monogenic and polygenic bone mass disorders, frailty and other musculoskeletal traits, have led

[6] 18O-assisted dynamic metabolomics for individualized diagnostics and treatment of human diseases

  • Authors: E. Nemutlu, Song Zhang, N. Juranic, A. Terzic, S. Macura et al.
  • Year: 2012
  • Venue: Croatian Medical Journal
  • URL: https://www.semanticscholar.org/paper/880f053c7f060db4b990e447d0a22c4b69372ddb
  • DOI: 10.3325/cmj.2012.53.529
  • PMID: 23275318
  • PMCID: 3541579
  • Citations: 28
  • Summary: The potential use of dynamic phosphometabolomic platform for disease diagnostics currently under development at Mayo Clinic is described and discussed briefly.
  • Evidence snippets:
  • Snippet 1 (score: 0.375) > Living cells represent an integrated and interacting network of genes, transcripts, proteins, small signaling molecules, and metabolites that define cellular phenotype and function. Traditionally the focus of biomedical research was on individual genes, single protein targets, single metabolites, and metabolic or signaling pathways. This "molecular reductionist" paradigm was based on the assumption that identifying genetic variations and molecular components would lead to discovery of cures for human diseases. However, most of diseases are complex and multi-factorial and the disease phenotype is determined by the alterations of multiple genes, pathways, proteins and metabolites (at cellular, tissue, and organismal levels). Therefore, an integrated "omics" approach is more viable direction for uncovering alterations in metabolic networks, disease mechanisms, and mechanisms of drug effects. > Recent advent of large-scale metabolomics and fluxomic (metabolite dynamics and metabolic flux analysis) completed the "omics revolution" (Figure 1), where genomics, transcriptomics, proteomics, metabolomics, and fluxomics all together complement phenotype determination of living organism. Such integrated "omics" cascades provide a framework for advances in system and network biology, integrative physiology, and system medicine as well as system pharmacology and regenerative medicine. Noteworthy is the "reverse omic" approach or "metabolomicsinformed pharmacogenomics, " where discovery of specific metabolite changes have led to discovery of genetic alterations (2). Therefore, bringing new "omics" technologies to clinical practice will improve disease diagnostics and treatment by targeting drugs and procedures for each unique transcriptomic and metabolomic profiles.

[7] Role of Transcriptomics in Precision Oncology

  • Authors: Ruby Srivastava
  • Year: 2024
  • Venue: Reports of Radiotherapy and Oncology
  • URL: https://www.semanticscholar.org/paper/0bd862558bbb7286336111d9dfd232b5f905d3d9
  • DOI: 10.5812/rro-142195
  • Citations: 4
  • Summary: : Transcriptome profiling is one of the most widely used approaches in the field of multiomics research. It plays a crucial role in the prognostic, diagnostic, and predictive treatment of cancer patients. Novel next-generation sequencing (NGS) technologies permit the identification of cancer biomarkers, gene signatures, and their abnormal expression, affecting oncogenic and molecular targets and novel biomarkers for cancer therapies. Multiomics studies have changed the overall understanding o...
  • Evidence snippets:
  • Snippet 1 (score: 0.356) > : Transcriptome profiling is one of the most widely used approaches in the field of multiomics research. It plays a crucial role in the prognostic, diagnostic, and predictive treatment of cancer patients. Novel next-generation sequencing (NGS) technologies permit the identification of cancer biomarkers, gene signatures, and their abnormal expression, affecting oncogenic and molecular targets and novel biomarkers for cancer therapies. Multiomics studies have changed the overall understanding of cancer and opened a precise perspective for tumor diagnostics and therapy. The use of these approaches has strengthened our understanding of disease pathophysiology and classifications at the molecular level, including specific interference with drug mechanisms of action. Still, it has limited added value in the clinical setting. The omics data on precision medicine include the application of data from genes, transcripts, and proteins for diagnosis, monitoring of diseases, risk factor determination, counseling, and development of novel therapeutics. Bioinformatics applications have expanded statistics-based analysis toward deriving molecular pathways and process models for characterizing phenotypes and drug action mechanisms. In this review, we will discuss transcriptomics and interference analysis that allows the identification of predictive biomarkers at the molecular level to test drug response and analyze the molecular process interface of disease progression-relevant pathophysiology and mechanism of action to propose predictive biomarkers.

[8] Heat Shock Proteins in Oxidative Stress and Ischemia/Reperfusion Injury and Benefits from Physical Exercises: A Review to the Current Knowledge

  • Authors: Jakub Szyller, I. Bil-Lula
  • Year: 2021
  • Venue: Oxidative Medicine and Cellular Longevity
  • URL: https://www.semanticscholar.org/paper/4ec4bee9f1b89cdf5a3c513d847990f3cfc18bb8
  • DOI: 10.1155/2021/6678457
  • PMID: 33603951
  • PMCID: 7868165
  • Citations: 112
  • Influential citations: 2
  • Summary: The latest research focuses on determining the role of H SPs in OS, their antioxidant activity, and the possibility of using HSPs in the treatment of I/R consequences, where reactive oxygen species play a major role.
  • Evidence snippets:
  • Snippet 1 (score: 0.356) > Heat shock proteins play a cytoprotective role under pathological conditions such as cardiovascular diseases. The knowledge about cellular and molecular mechanisms underlying ROS-mediated modulation of HSP expression can help to better understand the pathophysiology of OS, which is associated with the development of many diseases (cardiovascular, neurodegenerative, etc.). I/R injury is considered a major contributor to tissue damage in multiple clinical situations such as myocardial infarction, stroke, and organ transplantation. Oxidative damage is a key factor in the initiation of I/R. HSP expression is highly sensitive to I/R injury. > Understanding the exact mechanisms of HSP and the structure of the protein interaction network can help to better understand the pathophysiology and treatment of many diseases, as well as to develop new drugs. There is a need to understand the relationship between cell pathways-signaling, metabolism, etc. The relationships between HSP and OS discussed in this work seem to be very complicated and not yet fully understood. Data showed that modulation of HSP expression in reperfusion injuries may result in better treatment of myocardial infarction. This can also help to prepare organs for the transplantation.

[9] Direct Sarcomere Modulators Are Promising New Treatments for Cardiomyopathies

  • Authors: O. Tsukamoto
  • Year: 2019
  • Venue: International Journal of Molecular Sciences
  • URL: https://www.semanticscholar.org/paper/07467943fe92ce135b52ded5e5dea2bfc2ddf179
  • DOI: 10.3390/ijms21010226
  • PMID: 31905684
  • PMCID: 6982115
  • Citations: 16
  • Summary: The direct inhibition of sarcomere contractility may be able to suppress the development and progression of HCM with hypercontractile mutations and improve clinical parameters in patients with HCM, and direct activation of sar COMs modulators that can positively influence the natural history of cardiomyopathies represent promising treatment options.
  • Evidence snippets:
  • Snippet 1 (score: 0.356) > Hereditary DCM can be caused by single point mutations in sarcomere proteins. However, the link between point mutations and clinical phenotypes in DCM is not thoroughly understood in most cases. Recent advances in biochemical, biophysical, stem cell, and gene editing technologies have provided a better understanding of the molecular mechanisms through which the initial insult in DCM (i.e., mutations in a sarcomere protein) induces alterations in cellular organization and contractility, resulting in disease phenotypes. In particular, hiPSC-CMs and genetically modified animals are excellent models because they can capture the initial molecular phenotype that occurs before major compensatory mechanisms mask it.

[10] Signaling Pathways in Bone Development and Their Related Skeletal Dysplasia

  • Authors: Alessandra Guasto, V. Cormier-Daire
  • Year: 2021
  • Venue: International Journal of Molecular Sciences
  • URL: https://www.semanticscholar.org/paper/c5466b45e1a7e5aa8e7ad05c7d9287a9e84e9262
  • DOI: 10.3390/ijms22094321
  • PMID: 33919228
  • PMCID: 8122623
  • Citations: 51
  • Summary: The principal signaling pathways involved in bone development and their associated skeletal dysplasia are reviewed and genotype–phenotype correlations have helped to elucidate their role in skeletogenesis.
  • Evidence snippets:
  • Snippet 1 (score: 0.355) > In this review, we discussed the main signaling pathways involved in bone development and how mutations in their components have been associated with SD. It is important to highlight that even if the signaling pathways have been discussed independently, there is a complex cross-talk among them at multiple levels. This, in association with the evidence that the mutation consequences depend on the specificity of the mutations and on their temporal and spatial mode of action, makes more difficult the understanding of the physiopathological mechanisms of these diseases. Moreover, these signaling pathways can be secondarily affected by alterations in other cellular processes, such as extracellular matrix regulation or metabolic processing. Indeed, several skeletal dysplasia, that we decided to omit in this review, have been associated with mutations in these processes. Fortunately, in the last decade, the development of new technologies, like whole exome and genome sequencing has accelerated the identification of skeletal dysplasia-causing mutations. On the other hand, the development of CRISPR-Cas9 technology and of several mouse models is helping the deciphering of the physiopathological mechanisms. Advanced genetic testing is also helping the diagnosis of skeletal dysplasia. The diagnosis and management of these pathologies have long been based on clinical feature and skeletal imaging. Today, these key techniques are increasingly combined with the genetic testing in order to obtain a more accurate and early diagnosis of SD. It also aids in prognosis and in counselling families regarding genetic recurrence risk and preconceptional reproductive planning [212][213][214]. These continuous discoveries will help to expand the genotype-phenotype correlation of SD and to develop new therapeutic strategies. Nowadays, few treatments are available for SD, but several clinical trials are ongoing to validate new drugs targeting specifically these pathways in achondroplasia or FOP for example, and highlighting the importance of multidisciplinary cross talks (from bed to bench side) [215].

[11] Transcriptional profiling of intervertebral disc in a post‐traumatic early degeneration organ culture model

  • Authors: S. Cui, Zhiyu Zhou, Xu Chen, Fuxin Wei, R. G. Richards et al.
  • Year: 2021
  • Venue: JOR Spine
  • URL: https://www.semanticscholar.org/paper/c1f3b5a4f7f13275197f86e876b054a180e6dfc1
  • DOI: 10.1002/jsp2.1146
  • PMID: 34611583
  • PMCID: 8479529
  • Citations: 11
  • Summary: The goal of this study is to characterize transcriptome changes and gene regulation networks in an organ culture system that mimics early post‐traumatic intervertebral disc (IVD) degeneration.
  • Evidence snippets:
  • Snippet 1 (score: 0.354) > Consequently, the clinical management of IVD pathologies remains very limited, with no options at present for early intervention or predictive patient screening. > Therefore, there is a need for an improved understanding of the molecular pathophysiological mechanisms underlying IVDD, which is essential for diagnosis and the development of novel therapeutic approaches. Recently, the molecular basis of IVDD has received increased attention in research, which has substantially improved the understanding of the biology underlying this process. Studies investigating the molecular changes associated with the pathophysiology of IVDD have established criteria to distinguish degenerative IVDs. 4,10 udies evaluating transcriptome data using microarrays have provided us with an initial understanding of the molecular mechanisms underlying disc biology. 11,12 Furthermore, high-throughput screening of human patient samples may identify potential biomarkers of IVDD, leading to more precise diagnostic criteria, classification of disease progression, and prognosis. > Genes work in synergy with each other to perform biological functions. They simultaneously interact with multiple genes and trigger a variety of changes that lead to diverse reactions. The functional annotation of regulated genes, using Gene Ontology (GO), has enabled the identification of severely affected groups of genes that correlate with the disease phenotypes. 13 Therefore, the analysis of the gene expression profile by applying bioinformatics methods remains necessary to identify differentially expressed genes (DEGs) in IVDD and further elucidate the potential pathogenesis mechanisms of the disease. > High impact loading is one of the major causes leading to disc herniation. 14,15 The herniation may not occur right after the one strike overload, but years after. 7][18] Previously, we have established an IVDD model using one strike loading to mimic the post-traumatic pathological changes in whole organ cultured IVD. A single hyperphysiological mechanical compression applied to healthy bovine IVDs caused significant drop of cell viability, altered the mRNA expression in the IVD, and induced ECM degradation. 19 The present study aimed to identify the DEGs induced by one strike loading and further analyze their functions and pathways associated with the progression of IVDD by utilizing bioinformatics methods.

[12] Transcriptional profiling of Hutchinson-Gilford progeria patients identifies primary target pathways of progerin

  • Authors: Sandra Vidak, Sohyoung Kim, Tom Misteli
  • Year: 2026
  • Venue: Nucleus
  • URL: https://www.semanticscholar.org/paper/4bd99b0875508364d8672b6da5a50d024d485a53
  • DOI: 10.1080/19491034.2025.2611484
  • PMID: 41489464
  • PMCID: 12773485
  • Summary: To probe the clinical relevance of previously implicated cellular pathways and to address the extent of gene expression heterogeneity between patients, transcriptomic analysis of a comprehensive set of HGPS patients finds misexpression of several cellular pathways, including multiple signaling pathways, the UPR and mesodermal cell fate specification.
  • Evidence snippets:
  • Snippet 1 (score: 0.352) > Oxidative stress represents another key pathogenic mechanism in HGPS, as impaired NRF2 activity or increased reactive oxygen species (ROS) levels are sufficient to recapitulate HGPSassociated phenotypes [17,32,60]. Collectively, these findings underscore the multifactorial nature of HGPS pathogenesis, implicating interconnected signaling cascades involved in inflammation, oxidative stress, proteostasis, and vascular remodeling. Reassuringly, our findings indicate that many of the major pathways that have been described to contribute to HGPS phenotypes in mouse and cellular disease models are also misregulated in progeria patients, and targeting these pathways may provide therapeutic avenues to mitigate disease severity and improve outcomes in HGPS. > Although individuals with HGPS typically exhibit a characteristic set of clinical features, such as craniofacial abnormalities, growth retardation, and cardiovascular complications, there is notable variability in the age of onset, severity, and progression of symptoms between patients [7,9]. At the cellular level, HGPS is associated with several hallmark abnormalities, including nuclear envelope defects, decreased expression of several nuclear proteins and epigenetic marks, mitochondrial dysfunction, and increased cellular senescence [1,11,30,31,61]. These cellular phenotypes also exhibit considerable variation between patients, possibly contributing to differences in clinical outcomes. Our results indicate that even though some degree of transcriptional heterogeneity between the individual patients exists, the majority of patients exhibit misregulation of a set of shared pathways, suggesting that these pathways are universal driver mechanisms in HGPS. Further work is needed to understand the molecular and genetic factors that underlie inter-individual variability in disease expression and progression. > A limitation of pathway analysis of HGPS patient samples is to distinguish the pathways which are directly targeted by the disease-causing progerin protein and the emergence of adaptive secondary response pathways during progression of the disease in patients during their lifetime. The same caveat applies to the use of cell-based models used in the study of HGPS disease mechanisms.

[13] Skeletal Dysplasias Caused by Sulfation Defects

  • Authors: Chiara Paganini, Chiara Gramegna Tota, A. Superti-Furga, A. Rossi
  • Year: 2020
  • Venue: International Journal of Molecular Sciences
  • URL: https://www.semanticscholar.org/paper/e455f358a08f6e9fc09ef5f2d3751d11e9145e92
  • DOI: 10.3390/ijms21082710
  • PMID: 32295296
  • PMCID: 7216085
  • Citations: 25
  • Influential citations: 1
  • Summary: A panoramic view of skeletal dysplasias caused by mutations in genes encoding for transporters or enzymes involved in macromolecular sulfation is presented, allowing the development of targeted therapies aimed at alleviating, preventing, or modifying the disease progression.
  • Evidence snippets:
  • Snippet 1 (score: 0.351) > Over the last few years, there have been significant advances in the skeletal dysplasia field leading to the identification of the underlying genetic defects in more than 400 different skeletal disorders [15]. The above synopsis highlights the complexity of skeletal defects caused by mutations in genes encoding for enzymes and transporters involved in sulfate metabolism. Progress in this field has been allowed by next-generation genomic technologies, that are a first-line diagnostic resource. In this complex scenario, patient derived biopsies, cell cultures, and animal models are fundamental to investigate the pathogenesis and to analyze new aspects of the role of GAG in connective tissue biology. > Despite the great step forward in the identification of causative genes, genotype-phenotype correlations are lacking and we are still far from a comprehensive view of the disease molecular mechanisms. First, it is unclear how the tissue specificity and the redundancy of genes can determine the phenotype. Defects in PG sulfation mainly affect cartilage and bone, but other tissues can be involved as cardiac tissue in SEDCJD [82,84] or lymphoid tissue leading to tumour progression in OCBMD [91]. The involvement of different tissues and its implications on the disease phenotype should be carefully studied in the future. Moreover, mutations in different genes cause skeletal dysplasias with overlapping features that may be wrongly diagnosed as occurs in condrodysplasia with joint dislocation, gPAPP type, Catel-Manzke syndrome and Desbuquois dysplasia type 1. Nowadays we cannot provide a full explanation why some classes of sulfated PGs are more affected by enzyme deficiency than others. Even if the GAGs role depends on their physicochemical properties, it is difficult to molecularly dissect the function of sulfated GAGs when they interact in the complex ECM network. Lastly, the variability in the clinical phenotypes caused by mutations in the same gene suggests that also environmental and epigenetic factors might play a role. > A deep understanding of the molecular mechanisms of these disorders is crucial to ultimately pave the way for innovative therapies.

[14] Targeting Hepatic Stellate Cells for the Prevention and Treatment of Liver Cirrhosis and Hepatocellular Carcinoma: Strategies and Clinical Translation

  • Authors: Hao Xiong, Jinsheng Guo
  • Year: 2025
  • Venue: Pharmaceuticals
  • URL: https://www.semanticscholar.org/paper/76e92127053136900f7e3f10e2c9278251ced5d2
  • DOI: 10.3390/ph18040507
  • PMID: 40283943
  • PMCID: 12030350
  • Citations: 8
  • Summary: HSC-targeted approaches using specific surface markers and receptors may enable the selective delivery of drugs, oligonucleotides, and therapeutic peptides that exert optimized anti-fibrotic and anti-HCC effects.
  • Evidence snippets:
  • Snippet 1 (score: 0.350) > Significant progress has been made in elucidating the cellular and molecular mechanisms of liver fibrosis; however, only a few findings have been successfully translated into clinical applications. Firstly, the high cost of drug development and target validation necessitates prolonged timelines and substantial financial investment. Secondly, as regulatory requirements become more stringent, there is an increasing demand for drugs with well-defined clinical efficacy and safety profiles. Moreover, the efficacy observed in animal models often fails to fully translate to clinical settings due to differences in pharmacokinetics, extracellular matrix (ECM) cross-linking, and disease pathophysiology. Despite advancements in anti-fibrotic drug development, accurately identifying ideal noninvasive biomarkers for fibrotic activity and establishing consensus on optimal clinical endpoints remain significant challenges [113,114]. > Currently, addressing the underlying cause remains the only proven strategy to halt or reverse liver fibrosis progression, while the development of effective anti-fibrotic therapies continues to pose a major challenge in liver disease management. Over the past few decades, substantial progress has been made in elucidating the cellular and molecular mechanisms underlying liver fibrosis. Liver fibrosis is a complex pathological change involving multiple cells, factors, and pathways, and the study of the cellular and molecular mechanisms of its occurrence and development provides an important theoretical basis and therapeutic target for clinical drug development. It is anticipated that improved animal models and well-designed clinical trials will facilitate the successful translation of anti-fibrotic research into effective clinical treatments in the near future.

[15] Modeling psychiatric disorders: from genomic findings to cellular phenotypes

  • Authors: Anna Falk, Vivi M. Heine, A. Harwood, Patrick F. Sullivan, M. Peitz et al.
  • Year: 2016
  • Venue: Molecular Psychiatry
  • URL: https://www.semanticscholar.org/paper/235b41240d78140de7ab06a3ad8a7d0b1bdff1a5
  • DOI: 10.1038/mp.2016.89
  • PMID: 27240529
  • PMCID: 4995546
  • Citations: 77
  • Influential citations: 2
  • Summary: The challenges for modeling of psychiatric disorders, potential solutions and how iPSC technology can be used to develop an analytical framework for the evaluation and therapeutic manipulation of fundamental disease processes are critically reviewed.
  • Evidence snippets:
  • Snippet 1 (score: 0.349) > The key challenge for iPSC-based disease modeling is to identify one or more relevant cellular phenotypes that accurately represent the disease pathophysiology. Increasing numbers of reports have demonstrated that for many diseases specific pathophysiology can be captured in human iPSC-based disease models. These range from cardiovascular disease, 44,45 cancer, 46,47 ocular disease, 48,49 diabetes mellitus 50,51 and neurological disorders of the brain. 52,53 Can the same approach be applied to complex psychiatric disorders? > The problem is that almost all psychiatric disorders are characterized by clinical signs and symptoms, but lack independent verification from objective biomarkers. Thus, how might these clinical phenotypes manifest themselves in terms of cell behavior? The identity of robust cellular 'readouts', which typify any psychiatric disorder, is a crucial unsolved problem and an area of intense study 54 (Table 2). When satisfactorily answered, this will herald a new degree of biological objectivity and quantification for the study of psychiatric disorders. > The aim is to find a single or small number of cell phenotypes or parameters that strongly associate with psychiatric disorders, and establish a cellular profile characteristic of cells derived from the general patient population. Although a consensus set of cellular phenotypes for psychiatric disorder is yet to be established, we can define some of their desired characteristics. First, cellular phenotypes have to relate to the biological pathways identified by genetics. Second, although there are many risk genes in disparate biological pathways, at some level, phenotypes should converge onto a much smaller grouping. Third, phenotypes need to be quantifiable. Finally, to be useful for drug development cellular phenotypes should be reversed by pharmacological treatment, although not necessarily by drugs in current use. > Although human iPSC-based approaches underrepresent the complexity of the human central nervous system, cellular phenotypes are likely to lie more proximal to molecular disease mechanisms than phenotypes seen at the level of a tissue or organism, 55 and thus may bypass compensatory homeostatic (2) Gene expression profiles of SCZ human iPSC neurons identified altered expression of many components of the cyclic AMP and WNT signaling pathways. > (3

[16] Mitochondrial Dysfunction in Diabetes: Shedding Light on a Widespread Oversight

  • Authors: F. Iheagwam, A. J. Joseph, E. D. Adedoyin, Olawumi Toyin Iheagwam, Samuel Akpoyowvare Ejoh
  • Year: 2025
  • Venue: Pathophysiology
  • URL: https://www.semanticscholar.org/paper/dbf8042761c1a5fc50f8cd894cc498505abac7cb
  • DOI: 10.3390/pathophysiology32010009
  • PMID: 39982365
  • PMCID: 12077258
  • Citations: 25
  • Summary: This review aims to elucidate the complex link between mitochondrial dysfunction and diabetes, covering the spectrum of diabetes types, the role of mitochondria in insulin resistance, highlighting pathophysiological mechanisms, mitochondrial DNA damage, and altered mitochondrial biogenesis and dynamics.
  • Evidence snippets:
  • Snippet 1 (score: 0.349) > The landscape of DM research is continuously evolving, with emerging technologies and approaches offering new insights into the pathophysiology of the disease and potential therapeutic targets. Advancements in omics technologies, encompassing genomes, transcriptomics, proteomics, and metabolomics, have transformed the molecular mechanisms underlying DM [134]. High-throughput sequencing techniques enable comprehensive analysis of genetic variants, gene expression profiles, protein abundance, and metabolite levels associated with DM and its complications [135]. Single-cell omics approaches provide unprecedented resolution and granularity, allowing researchers to dissect cellular heterogeneity and identify novel cell types, subpopulations, and signalling pathways involved in DM pathogenesis. Integrating multi-omics data sets offers a systems-level perspective of DM, unravelling complex networks of molecular interactions and regulatory circuits underlying disease progression [136]. > In addition to omics technologies, advances in imaging modalities, such as MRI, PET, and optical imaging, enable non-invasive visualisation and quantification of metabolic, functional, and structural changes. Molecular imaging probes targeting specific biomarkers and metabolic pathways provide valuable insights into disease mechanisms and treatment responses in preclinical and clinical settings [85]. Despite significant progress in DM research, numerous unanswered questions and knowledge gaps persist, hindering the ability to develop effective prevention and treatment strategies. Key areas requiring further investigation include the role of epigenetics, environmental factors, and the microbiome in DM susceptibility and progression. Moreover, the interaction between environmental cues and genetic predisposition remains incompletely understood, highlighting the need for comprehensive multi-omics studies and large-scale epidemiological analyses to identify gene-environment interactions and modifiable risk factors for DM [137]. Furthermore, the heterogeneity of DM phenotypes and clinical outcomes poses a challenge for personalised medicine approaches, necessitating robust biomarkers and predictive models to stratify patients based on disease subtypes, prognosis, and treatment response [138].

[17] Nasopharyngeal Carcinoma Signaling Pathway: An Update on Molecular Biomarkers

  • Authors: W. Tulalamba, T. Janvilisri
  • Year: 2012
  • Venue: International Journal of Cell Biology
  • URL: https://www.semanticscholar.org/paper/307cb9186444d9dad6e2e3b53763be0de76de186
  • DOI: 10.1155/2012/594681
  • PMID: 22500174
  • PMCID: 3303613
  • Citations: 93
  • Influential citations: 5
  • Summary: The molecular signaling pathways in the NPC are discussed for the holistic view of NPC development and progression and the important insights toward NPC pathogenesis may offer strategies for identification of novel biomarkers for diagnosis and prognosis.
  • Evidence snippets:
  • Snippet 1 (score: 0.349) > In the pregenomic eras, highly integrated and complex circuitry of molecular signaling in NPC pathogenesis was only partially understood. Over the past decade, the knowledge of the molecular mechanisms in NPC carcinogenesis has been rapidly accumulated. Dysregulation and abnormal protein expression of molecules in certain signaling pathways involved in cellular functions including proliferation, adhesion, survival, and apoptosis has been demonstrated in the NPC cells. Detailed information on the complex network in signaling pathway leading to a coordinated pattern of gene expression and regulation in NPC will undoubtedly provide important clues to develop novel prognostic and therapeutic strategies for this cancer. Refining molecular markers into clinically relevant assays may assist in the detection of NPC in asymptomatic patients, as well as stage classification and monitoring disease progression and treatments. Furthermore, selective regulation of particular proteins targeting cancer cell proliferation, invasion, and apoptosis is a hopeful prospect for future anticancer therapy that slow disease progression and improve survival.

[18] Cardiomyocytes Derived from Induced Pluripotent Stem Cells as a Disease Model for Propionic Acidemia

  • Authors: Esmeralda Alonso-Barroso, B. Pérez, L. Desviat, E. Richard
  • Year: 2021
  • Venue: International Journal of Molecular Sciences
  • URL: https://www.semanticscholar.org/paper/da649a0f04477c53b448c5ac5f873f8762235290
  • DOI: 10.3390/ijms22031161
  • PMID: 33503868
  • PMCID: 7865492
  • Citations: 16
  • Influential citations: 1
  • Summary: The novel results show that PA iPSC-cardiomyocytes represent a promising model for investigating the pathological mechanisms underlying PA cardiomyopathies, also serving as an ex vivo platform for therapeutic evaluation.
  • Evidence snippets:
  • Snippet 1 (score: 0.347) > The study of the mechanisms involved in disease physiopathology has been mainly performed using the hypomorphic PA mouse model that mimics the biochemical and clinical phenotype [5]. Using this model, bioenergetic failure, oxidative damage and deregulation of miRNAs induced by accumulating propionyl-CoA have been described as potential mechanisms contributing to PA physiopathology [6][7][8]. The limitations of animal models for the study of cardiac energy metabolism [9] and of the commonly available cellular human models such as fibroblasts, underline the importance of generating new relevant cell models to provide deeper insight into the underlying mechanisms of disease. The use of in vitro models with human cellular context is highly recommended and, in this sense, induced pluripotent stem cells (iPSCs) have certain advantages since they provide the genetic background of the patient and represent an unlimited source of biological material for the study of pathophysiology and treatment effectiveness [10]. We have previously generated an iPSC line from a PA patient with defects in the PCCA gene that showed full pluripotency, differentiation capacity and genetic stability [11]. > In the present study, we aimed to establish a platform that served as a disease model to study the cellular and molecular alterations operating in cardiac tissue affected by PA disease. We described the characterization of cardiomyocytes derived from the PCCA iPSC line (PCCA iPSC-CMs) and the analysis of specific pathways potentially involved in cardiac PA physiopathology.

[19] Cellular reprogramming and inherited peripheral neuropathies: perspectives and challenges

  • Authors: M. Saporta
  • Year: 2015
  • Venue: Neural Regeneration Research
  • URL: https://www.semanticscholar.org/paper/8c3dabb1b4abf93506e2026564b8a329c0ec37c6
  • DOI: 10.4103/1673-5374.158345
  • PMID: 26199602
  • PMCID: 4498347
  • Citations: 4
  • Summary: iPSC-based models of neuromuscular disorders, including amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA) and inherited peripheral neuropathies, have successfully reproduced pathophysiological findings from previous animal and cellular models and have also identified new disease mechanisms with potential therapeutical implications.
  • Evidence snippets:
  • Snippet 1 (score: 0.345) > Inherited peripheral neuropathies (or Charcot-Marie-Tooth disease, CMT) are a phenotypically and genetically heterogeneous group of disorders, which are currently untreatable. They are the most common inherited neuromuscular disorder, affecting around 1 in every 2,500 people (over 120,000 people in the US). Based on clinical neurophysiological and histopathological features, inherited neuropathies can be divided into two major forms: demyelinating (type 1) and axonal (type 2) CMT (Saporta, 2014). From a biological standpoint, these two major forms of CMT are associated with mutations in different sets of genes, affecting Schwann cell development and myelination (type 1) or peripheral axon physiology (type 2), although some overlap does exist (Figure 1). To date, over 70 genes have been associated with a CMT phenotype, making CMT an attractive natural model to study peripheral nervous system biology. Despite significant advances made in our knowledge of disease mechanisms in CMT, findings from animal models have so far translated poorly in clinical trials, underscoring the need for innovative methods to investigate the pathophysiology of these human disorders. Induced pluripotent stem cells (iPSCs) offer an unlimited source of patient specific, disease-relevant cell lines that can be used as a platform for identification of disease mechanisms, discovery of molecular targets and development of phenotypic screens for drug discovery (Saporta et al., 2011). iPSC-based models of neuromuscular disorders, including amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA) and inherited peripheral neuropathies, have successfully reproduced pathophysiological findings from previous animal and cellular models and have also identified new disease mechanisms with potential therapeutical implications.

[20] Molecular insights into the premature aging disease progeria

  • Authors: Sandra Vidak, R. Foisner
  • Year: 2016
  • Venue: Histochemistry and Cell Biology
  • URL: https://www.semanticscholar.org/paper/60fb3b46bb7e42d5d08cc3b7cbc783b118300c31
  • DOI: 10.1007/s00418-016-1411-1
  • PMID: 26847180
  • PMCID: 4796323
  • Citations: 105
  • Influential citations: 3
  • Summary: Changes in mechanosignaling, altered chromatin organization and impaired genome stability, and changes in signaling pathways, leading to impaired regulation of adult stem cells, defective extracellular matrix production and premature cell senescence are discussed.
  • Evidence snippets:
  • Snippet 1 (score: 0.345) > The number of molecular biological studies aiming at the identification of lamin-mediated molecular disease mechanisms involved in HGPS increased tremendously following the surprising discovery that LMNA is causally linked to the premature aging disease HGPS in 2003. Despite numerous cellular pathways that were identified to be affected by the expression of the mutant lamin A protein (Fig. 2), the mechanistic details behind these effects are still unclear in most cases. Knowledge based on what was already known on lamin biology before the protein was linked to HGPS and findings on novel roles of lamins in diverse pathways in recent years allowed the launch of translational studies and the efficient search for drug targets and therapeutic approaches within a short time period. The results of the first clinical trials taught us that some improvements of the disease phenotypes can be achieved by FTI treatment, but they also made clear that we need a much better understanding of the underlying disease mechanisms to be able to tackle specific aspects of the disease in a more focused approach. It will also be important to elucidate which of the numerous pathways found to be impaired in HGPS are most relevant for and causally involved in the pathologies, and which ones are just bystanders.

Notes

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