Identification of a novel candidate HSD3B2 gene variant for familial hypospadias by whole-exome sequencing

Understanding of pathogenic manifestation and inheritance of confounding genetic variants in hypospadias is a matter of great concern, especially in familial cases.

An abnormal fetal steroidogenic pathway due to genetic influences may affect the development of the male genital tract, including the urethral tract closure and morphogenesis of male genitalia. Furthermore, the pathogenicity of the observed variant in this study, confirmed by multiple in silico tools, characterizes the influence HSD3B2 gene variants may have in the etiology of hypospadias. Conclusion: Understanding of pathogenic manifestation and inheritance of confounding genetic variants in hypospadias is a matter of great concern, especially in familial cases.

Surgical hypospadias repair was performed on two hypospadias-affected siblings from a consanguineous family. Whole-exome sequencing (WES) was performed to identify the potential pathogenic variant for hypospadias, which was later confirmed by Sanger sequencing. The identified variant was further analyzed for its pathogenicity by using in silico tools such as SIFT, PolyPhen-2, MutationAssessor, MutationTaster, FATHMM, and ConSurf.

Surgical hypospadias repair was performed on two hypospadias-affected siblings from a consanguineous family. Whole-exome sequencing (WES) was performed to identify the potential pathogenic variant for hypospadias, which was later confirmed by Sanger sequencing. The identified variant was further analyzed for its pathogenicity by using in silico tools such as SIFT, PolyPhen-2, MutationAssessor, MutationTaster, FATHMM, and ConSurf.

We identified a novel missense mutation (Chr1:119964631T>A, c.507T>A, p. N169K) in 3β-hydroxysteroid 2-dehydrogenase (HSD3B2) gene by WES. Sanger sequencing confirmed that the variant segregated the disease in the family between the affected and non-affected individuals. Both patients are homozygous, while parents and two unaffected siblings are heterozygous carriers, indicating an autosomal recessive pattern of inheritance. The in silico analysis by all six in silico tools (SIFT, PolyPhen-2, MutationAssessor, MutationTaster, FATHMM, and ConSurf) predicted the variant to be pathogenic/deleterious.