Introduction: Steroidogenic factor-1 (SF1/NR5A1) is a nuclear receptor, which regulates genes that have functions in the development of adrenal glands and gonads, reproduction, and other metabolic functions.
Case presentation: A 20-day-old infant was admitted due to ambiguous genitalia. Physical examination revealed a 2×1 cm phallus, bifid scrotum, and hypospadias. Both gonads were palpable in the inguinal canal. Serum levels of adrenal androgens (17-OH progesterone, DHEAS, androstenedione) and gonadotropins were within normal limits. Uterus could not be visualized on pelvic ultrasonography. In peripheral blood chromosome analysis 46, XY karyotype was detected. Initially, partial androgen insensitivity and 5α-reductase deficiency were suspected. The patient was reared as male according to the decision of Gender Assignment Council. After decision, he underwent orchiopexy and surgical repair for hypospadias. At the age of 11 years, his pubertal development was normal with pubic hair Tanner stage III and both testes palpable as 6 ml. Hormonal evaluation revealed: LH: 7.1 IU/l, FSH: 23.1 IU/l, total testosterone: 164 ng/dl, and testosterone/dihydrotestosterone ratio was 22. After hCG stimulation test (3 000 IU/day, 3 days), total testosterone level was measured as 368 ng/dl (Δtestosteron=204 ng/dl). Next generation sequencing of SF1 gene revealed a novel heterozygote mutation at T272P (c.814A>C). Analyses of the parents detected 17% mosaicism in the fathers leukocyte DNA. Buccal smear sample to confirm mosaicism status of the father also detected the same level of mosaicism. Adrenal insufficiency was excluded with a standard dose ACTH stimulation test, which revealed a peak cortisol level of 27.8 μg/dl.
Conclusion: We report a novel mutation in SF1 gene in a patient with 46, XY DSD without adrenal insufficiency. Additionally, we detected a low-level paternal mosaicism with next generation sequencing.
01 - 03 Oct 2015
European Society for Paediatric Endocrinology