A new compound heterozygous mutation in a female with 17α-hydroxylase/17,20-lyase deficiency, slipped capital femoral epiphysis, and adrenal myelolipoma.

17α-Hydroxylase/17,20-lyase deficiency (17-OHD) is a rare disease caused by mutations of the CYP17A1 gene. Slipped capital femoral epiphysis (SCFE) rarely occurs in adults. There are occasional reports of adrenal myelolipoma (AML) in 17-OHD. A 27-year-old Chinese female (46, XX) visited the hospital for SCFE and presented with continuous hypokalemia, absent spontaneous puberty, and hypertension. Hypergonadotropic hypogonadism was detected. The laboratory tests were consistent with 17-OHD. AML was considered based on the imaging examinations. A mutation analysis of the CYP17A1 gene identified the following compound heterozygous mutation: a frame-shift mutation, i.e. c.985_987delTACinsAA (p.Tyr329fs), that had been reported to be a common mutation in the Chinese population was found in exon 6. Another new nonsense mutation, i.e. c.1270C > T (p.Gln424*), that causes a premature termination codon was found in exon 8. Treatment with prednisone had poor efficacy. The administration of 0.75 mg dexamethasone and estradiol/dydrogesterone cyclic treatment significantly improved the patient's symptoms. For the first time, we report a 17-OHD case accompanied by SCFE, AML, and a novel mutation site in the CYP17A1 gene. We provide insight into the clinical manifestations, genetic analysis, and treatment options of 17-OHD.