Clinical Features of Unrecognized Congenital Adrenal Hyperplasia Due to 17α-hydroxylase Deficiency Since Adolescence: A Case Report

The majority of patients with congenital adrenal hyperplasia (CAH) present with a deficiency of 21-hydroxylase or 11-beta-hydroxylase, which account for 90% and 7% of cases, respectively. However, CAH due to 17α-hydroxylase deficiency (17OHD) is an extremely rare form of CAH (<1% of all CAH cases) that leads to a deficiency of cortisol and sex steroids, along with features of aldosterone excess. This is a case of a 51-year-old single female who was referred to us for the evaluation of new-onset hypertension and hypokalaemia of one-year duration. She was born out of a second-degree consanguineous marriage and reared as a female. She was diagnosed to have testicular feminization syndrome when she presented with a history of primary amenorrhea, absence of secondary sexual characteristics, and bilateral labial swellings at pubertal age. Subsequently, she underwent gonadectomy at the age of 16. Due to the presence of hypertension, metabolic alkalosis and bilaterally enlarged adrenals on CT scan, 46, XY disorders of sexual development (DSD) was considered. A karyotype confirmed the presence of 46, XY chromosomal sex, and genetic analysis revealed a mutation in the CYP17A1 gene, thus confirming the diagnosis of 17α-hydroxylase deficiency.