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IEMbase 0117: CYP17A1-related 17-alpha-hydroxylase deficiency

Scope

Field Value
IEMbase ID 117
Nosology 24.2.05.01
Gene CYP17A1
External IDs OMIM:202110; ORPHA:418
Generated mapping MAPPED, high confidence
Candidate DisMech targets Congenital_Adrenal_Hyperplasia.yaml#17A-OHD
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as CYP17A1-related 17-alpha-hydroxylase deficiency, with alternate labels congenital adrenal hyperplasia and P450c17 deficiency. Treatability is marked unknown.

The characteristic biochemical rows show mineralocorticoid precursor excess and sex-steroid/cortisol deficiency: low potassium, high sodium, high corticosterone, low cortisol, high deoxycorticosterone, high progesterone, and low sex hormones. Clinical rows include adrenal hyperplasia, alkalosis, and hypertension. Glucocorticoids are listed as treatment.

DisMech phenotype coverage

Congenital_Adrenal_Hyperplasia.yaml includes a 17A-OHD subtype and a CYP17A1 17-hydroxylase/17,20-lyase deficiency mechanism. The local entry explicitly frames CYP17A1 deficiency as cortisol deficiency, sex-steroid deficiency, and mineralocorticoid excess. It also links this mechanism to hypertension in the phenotype section.

The local CAH treatment section includes glucocorticoid replacement, but the entry is primarily optimized around 21-hydroxylase deficiency and broader CAH management rather than detailed CYP17A1-specific steroid profiling.

Concordance and completeness

Judgement: correct subtype-level mapping, with IEMbase richer for biochemical resolution.

The mapping is concordant for CYP17A1/17A-OHD and for the hypertension/mineralocorticoid excess phenotype. DisMech captures the essential mechanism and subtype identity. IEMbase adds important diagnostic granularity: low potassium, high sodium, corticosterone, deoxycorticosterone, progesterone, cortisol, and sex hormone profiles across age bins. These are not present as discrete local biochemical rows.

Curation actions

  • Keep Congenital_Adrenal_Hyperplasia.yaml#17A-OHD as the current target.
  • Consider adding subtype-specific biochemical rows for deoxycorticosterone, corticosterone, potassium, sodium, cortisol, and sex hormone deficiency.
  • Review whether delayed/absent puberty or undervirilization phenotypes should be made explicit for CYP17A1 deficiency in addition to hypertension.