A rare cause of delayed puberty and primary amenorrhea: 17α-hydroxylase enzyme deficiency

17α-hydroxylase enzyme deficiency is a rare form of congenital adrenal hyperplasia (CAH) and is caused by mutations in the CYP17A1 gene. The main clinical findings are delayed puberty and primary amenorrhea in girls, and disorders of sex development in boys. It can also cause hypertension and hypokalemia in both genders. In this study, we aimed to present the clinical, laboratory and genetic results of 13 patients from eight different families who were diagnosed with complete 17α-hydroxylase enzyme deficiency.

The age, symptoms, anthropometric measurements, blood pressure, Tanner stages, and hormonal and chromosome analysis results at the time of admission were recorded from the medical records of the patients. Whole gene next-generation sequencing of CYP17A1 gene was performed to detect mutations. Multiplex ligation dependent probe amplification (MLPA) method were used to detect deletions in the seven patients who had no point mutation were detected in the CYP17A1 gene.

The average age of the patients at the time of admission was 14.8 (range: 12.9-16.6) years. Also at this time, all patients were in adolescence and were raised as females. The karyotypes of eight patients were 46,XY, and of five patients were 46,XX. Ten patients presented with delayed puberty and primary amenorrhea, one patient with delayed puberty and hypertension, and two patients with hypertension and/or hypokalemia. Hypertension and hypokalemia were detected in nine and seven patients, respectively.

P450c17 enzyme deficiency should be considered in patients presenting with delayed puberty or primary amenorrhea in the adolescence period and diagnosed with hypergonadotropic hypogonadism, if hypertension and hypokalemia accompany. Early diagnosis prevents the occurrence of important health problems such as hypertension, psychological problems, and gender identity disorders, which affect the majority of these patients.