Clinical, hormonal and molecular genetic characteristics of 18 cases of disorders of sex development (DSD) 46,XY associated with variants in the SRD5A2 gene

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.

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