A novel loss-of-function variant in DNHD1 linked to human asthenozoospermia.

OBJECTIVE

Asthenozoospermia, characterized by diminished sperm motility, shows substantial genetic heterogeneity. Although many familial cases of asthenozoospermia have been documented, the genetic etiology for most affected males remains unknown.

METHODS

This study used clinical and molecular approaches to characterize a hereditary form of asthenozoospermia. Two patients born to consanguineous parents exhibited impaired sperm motility. Whole-genome sequencing (WGS), followed by Sanger sequencing, was performed for molecular diagnosis and was coupled with three-dimensional protein modeling to characterize the identified variant.

RESULTS

WGS revealed that both affected brothers carried a pathogenic variant (c.580C>T; p.Gln194*) in dynein heavy chain domain 1 (DNHD1). Homozygous variants in DNHD1 have previously been linked to spermatogenic failure 65 (Online Mendelian Inheritance in Man [OMIM] 619712). Three-dimensional protein modeling demonstrated significant alterations in DNHD1 secondary structure that could contribute to loss-of-function.

CONCLUSION

These findings support a role for DNHD1 in maintaining the structural and functional integrity of sperm. Accurate molecular diagnosis may facilitate genetic counseling and inform clinical management.