Abstract
INTRODUCTION: Among the disorders of sex development (DSD) with karyotype 46,XY, there is a group of diseases caused by defects of androgen synthesis. The last stage of in the synthesis of androgens is the conversion of testosterone into a more active androgen dihydrotestosterone, which occurs under the influence of the enzyme 5α-reductase type II (SRD5A2). SRD5A2 deficiency is a rare disease with autosomal recessive inheritance. AIM: To give a clinical and molecular genetic characterization of 14 new cases with confirmed molecular diagnosis of SRD5A2 deficiency, as well as 4 cases of DSD 46,XY, where monoallelic changes in the SRD5A2 gene were detected. MATERIALS AND METHODS: The study included 310 patients with DSD 46,XY. Molecular genetic analysis was performed using the NGS method using a targeted panel for multiplex amplification and subsequent sequencing of the coding regions of the following genes: AKR1C2, AKR1C4, AMH, AMHR2, AR, ARX, ATRX, CBX2, CYB5A, CYP11A1, CYP17A1, DHCR7, DHH, EMX2, ESR2, FGD1, FGF9, FGFR2, FKBP4, FOXF2, FOXL2, HOXA13, HSD17B3, HSD3B2, ICK, LHCGR, LHX1, LHX9, MAMLD1, MAP3K1, MID1, NR0B1, NR5A1, POR, PTGDS, SOX9, SRD5A2, SRY, STAR, SUPT3H, TSPYL1, WNT4, WT1, ZFPM2. RESULTS: By molecular genetic analysis 16 different variants were identified in the SRD5A2 gene (2 in several families), 4 of which had not been previously described. CONCLUSION: The study highlights the importance of molecular genetic analysis in the differential diagnosis of DSD 46,XY.