Congenital adrenal hyperplasia, CYP21A2 gene, premature pubarche, virilization, 21-hydroxylase deficiency

Introduction: 46,XY complete gonadal dysgenesis (Swyer syndrome) is a rare cause of sex differentiation disorders. This syndrome is caused by defects during embryogenesis’ sex determination and presents with 46,XY sex-reversed female phenotype, uterine hypoplasia, bilateral streak gonads, and hypergonadotropic hypogonadism.
Case: A 16-year-5-month-old female patient presented with primary amenorrhea and absent breast development, axillary and pubic hair. Physical examination revealed a weight of 42.5 kg [<3rd p, -2.02 standard deviation score (SDS)], a height of 152 cm (3rd-10th p, - 1.68 SDS), and normal vital signs. Genital examination disclosed female external genitalia with no cliteromegaly, hirsutism, or acne. The target height was 148 cm, and bone age revealed 12 years. Follicle-stimulating hormone, luteinizing hormone, estradiol, and total testosterone levels were respectively 115.7 mIU/mL, 29.78 mIU/mL, <5 pg/mL, and 0.029 ng/mL. Ultrasound imaging revealed uterine hypoplasia, bilateral streak gonads, and horseshoe kidneys. As karyotype analysis revealed 46,XY and SRY + was detected by quantitative fluorescent polymerase chain reaction, Swyer syndrome (complete gonadal dysgenesis) was diagnosed. Prophylactic bilateral gonadectomy was performed to prevent development of gonadoblastoma. No evidence of neoplasia (gonadoblastoma) was observed in the gonadectomy material; gonad karyotype analysis revealed 46,XY.
Conclusion: We emphasize the importance of karyotype analysis in patients with delayed puberty and primary amenorrhea. Prophylactic bilateral gonadectomy should be kept in mind for complete gonadal dysgenesis to prevent the development of gonadal malignancy.