Late diagnosis of classic congenital adrenal hyperplasia: long-term consequences during adulthood.

Summary Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders related to enzyme deficiencies in the adrenal steroidogenesis pathway leading to impaired corticosteroid biosynthesis. Depending on the extension of enzyme defect, there may be variable severities of CAH - classic and non-classic. We report the case of a 37-year-old male patient with a previously unknown diagnosis of classic CAH referred to Endocrinology evaluation due to class III obesity and insulin resistance. A high diagnostic suspicion was raised at the first Endocrinology consultation after careful past medical history analysis especially related to the presence of bilateral adrenal myelolipomas and primary infertility. A genetic test confirmed the presence of a variant of the CYP21A2 in homozygous with an enzymatic activity of 0-1%, corresponding to a classic and severe CAH form. Our case represents an unusually late definitive diagnose of classic CAH since the definition was established only during adulthood in the fourth decade of life. The missing diagnosis of classic 21 hydroxylase deficiency during infancy led to important morbidity, with a high impact on patients' quality of life. Learning points Congenital adrenal hyperplasia (CAH) refers to a group of autosomal recessive enzyme disorders responsible for an impaired cortical adrenal hormonal synthesis. CAH may be divided into two major forms: classic and non-classic CAH. If untreated, CAH may be fatal or may be responsible for important multi-organ long-term consequences that can be undervalued during adulthood. Adrenal myelolipomas are associated with chronic exposure to high ACTH levels and continuous androgen hyperstimulation typically found in undertreated CAH patients. Testicular adrenal rest tumours (TART) and primary infertility can be the first manifestation of the disease during adulthood.