[Diffuse hypertrichosis revealing non-classical congenital adrenal hyperplasia]

Area of Science:

• Endocrinology
• Genetics
• Pediatrics

Background:

• Non-classical congenital adrenal hyperplasia (NC-CAH) is an autosomal recessive disorder affecting adrenal steroidogenesis.
• It presents with milder symptoms than classical CAH, often diagnosed later in life.
• Distinguishing NC-CAH is crucial to avoid misdiagnosis of more severe conditions.

Observation:

• Two 5-year-old twin girls presented with diffuse hypertrichosis on limbs and chin comedones.
• Clinical examination revealed normal growth, development, and no signs of precocious puberty or clitoral hypertrophy.
• Biochemical tests showed elevated 17OH-P and SDHA, with low FSH and LH.

Findings:

• Genetic analysis identified CYP21 gene mutations (p.V281L and IVS2-13A/C>G) associated with NC-CAH.
• The p.V281L mutation was found in the heterozygous state in one twin and the father.
• The findings suggest NC-CAH as the cause of hypertrichosis in the twins, with potential de novo mutation or maternal mosaicism.

Implications:

• NC-CAH is more prevalent than previously thought (1/1000-1500 in European descent) and often diagnosed late.
• Hypertrichosis can be an isolated symptom of NC-CAH, necessitating dermatological awareness for early diagnosis.
• Prompt diagnosis allows for appropriate management, including hormone replacement or cosmetic treatments, to address hyperandrogenism.