A Case Report of 17α-Hydroxylase Deficiency in Two Saudi Siblings With Different Karyotyping.

Congenital adrenal hyperplasia (CAH) consists of variable disorders of sex determination and differentiation. 17α-hydroxylase deficiency (17OHD) is an uncommon form of those disorders, which is typically characterized by hypertension, hypokalemia, failure of puberty, and ambiguous genitalia. The 17α-hydroxylase enzyme is encoded by the CYP17A1 gene and it is required for the synthesis of cortisol and sex steroids. The affected females with 17OHD usually present with primary amenorrhea and delayed puberty, which are associated with hypertension and hypokalemia while male patients might show female external genitalia, pseudohermaphroditism, or variable degrees of ambiguous genitalia with intra-abdominal testes in addition to hypertension and hypokalemia as well. We present two Saudi siblings (19 and 16 years old) who were diagnosed with the rare CAH subtype of 17OHD after presenting with long-standing hypertension, refractory hypokalemia, and failure of puberty. It is interesting that both siblings had biochemical primary adrenal insufficiency; however, both patients did not clinically present with an acute adrenal crisis, which is likely due to the effect of increased levels of deoxycorticosterone. Additionally, although both patients have similar phenotypes and clinical presentations, they have different karyotypes. This again highlights the variability of the manifestations that can result from 17OHD even with an identical mutation in the same family. Both patients were treated successfully with dexamethasone, which has led to the normalization of hypertension, resolution of hypokalemia, and discontinuation of anti-hypertensive medications and potassium supplements after several years of treatment. However, the entire management is quite challenging and requires a multidisciplinary approach regarding difficult issues such as gender identity and assignment and fertility issues in addition to a life-long follow-up.