5-α reductase deficiency is one of 46,XY disorders of sexual differentiation characterized by androgen metabolism disorder. In the literature, there are few cases with 5-α reductase deficiency reared as girl.
A 12-year and 8-month-old female patient presented with primary amenorrhea, absent breast development, axillary and pubic hair. Physical examination revealed a weight of 53.9 kg [75-90p, 0.87 standard deviation score (SDS)], a height of 167 cm (95p, 1.72 SDS), and normal vital signs. Genital examination disclosed female external genitalia with no cliteromegaly, hirsutism, or acne. The target height was 160.2 cm, and bone age revealed 12 years.
Follicle-stimulating hormone, luteinizing hormone, estradiol, and total testosterone levels were 3.68 mIU/mL, 3.04 mIU/mL, <10 pg/mL, and 202.76 ng/mL. Adrenocorticotropic hormone and serum cortisol levels were normal in terms of adrenal insufficiency. Ultrasound imaging revealed no uterus and ovary. Karyotype analysis revealed 46,XY and SRY + was detected by quantitative fluorescent polymerase chain reaction. 5-α reductase deficiency was diagnosed with homozygous IVS3+1G>T (c.547+1G>T) mutation. Prophylactic bilateral gonadectomy was planned.
We emphasize the importance of karyotype analysis in patients with delayed puberty and primary amenorrhea. Prophylactic bilateral gonadectomy should be kept in mind for 5-α reductase deficiency in patients reared as girl to prevent the development of gonadal malignancy.