Hiperplasia adrenal congénita causada por una mutación (Val-281-Leu) de la enzima 21-hidroxilasa.

BACKGROUND: Congenital adrenal hyperplasia is an autosomal recessive disorder caused by a defect in adrenal steroidogenesis. The non-classical variant begins at puberty and is manifested by menstrual irregularities, hirsutism, genital hyperpigmentation, clitoral hypertrophy, accelerated growth, and elevated levels of testosterone and other androgens. Individuals with these non-classical forms of the disease are born with normal-appearing genitalia and begin clinical manifestations with the steroidogenic stimulus characteristic of adolescence. CLINICAL CASE: A 16-year-old female patient seen at the endocrinology clinic for menstrual irregularities and hirsutism, menarche at 13 years of age with menstrual irregularities (oligomenorrhea) and recession of the frontal hairline, breast and pubic hair development grade 4 on the Tanner scale for both features. The diagnosis of late-onset 21-hydroxylase blockade (non-classical form) was established. Initial treatment consisted of metformin and cyproterone, with marked relieve of hyperandrogenism and correction of menstrual irregularities. CONCLUSIONS: Late-onset non-classical congenital adrenal hyperplasia is due to a homozygous point mutation of the CYP21A2 gene, which in turn is due to a coding error at position 281 of the 21-hydroxylase protein, consisting of a substitution of the amino acid valine for leucine and resulting in complete inactivation of both alleles of the enzyme. [ABSTRACT FROM AUTHOR]