Whole exome sequencing applied to 42 Han Chinese patients with posterior hypospadias

Abstract

Hypospadias, a malformation of male external genitalia, is characterized by an aberrant opening of the urethra on the ventral side of the penis. It is considered a complex disorder with both environmental and genetic factors involved in its pathogenesis. To identify the genetic abnormality involved in the pathogenesis of hypospadias, we performed whole exome sequencing (WES) analysis in 42 hypospadias patients with karyotype 46, XY in the Nanhai Meternity&Child Health Hospital of Foshan. All the likely pathogenic variants were confirmed by Sanger sequencing and assessed by Sorting Intolerant from Tolerant (SIFT), PROVEAN, PolyPhen2, ClinPred, LRT, Mutation Assessor, FATHMM, and GERP software. We discovered 27 gene mutations in 20 patients, including eight cases of the SRD5A2 gene, 4 cases of the AR gene, 3 cases of the CYP17A1 gene, 1 case of the WT1 gene, 1 case of the ANOS1 gene, 1 case of the NR5A1 gene, 1 case of the FGFR1 gene, and one case of the DHX37 gene. Our study is the first to describe six novel missense mutations, AR(c.302G > A, c.2593G > T, and c.1705G > T), CYP17A1(c.1298 T > C), FGFR1 (c.995C > T) and DHX37(c.923G > A). In summary, genetic defect detection was useful for early diagnosis of severe hypospadias in the Han Chinese population. Nevertheless, most cases remain unexplained, and the exact pathogenesis of hypospadias still needs further study.

Keywords: Genetics; Hypospadias; Mutation; Whole exome sequencing.