Objective: To explore the clinical feature and gene variant for two cases of primary male infertility caused by severe asthenospermia and to analyze the etiology of the disease.
Methods: Genomic DNA of peripheral blood samples of patients and their parents was extracted and gene variant analysis of the patients was conducted by using whole exome sequencing. Suspected pathogenic variant was verified by Sanger sequencing and pathogenic analysis.
Results: Whole exome sequencing showed that the DNAH1 gene of patient 1 had two heterozygous variants of c.2016T>G(p.Y672X) and c.6017T>G (p.V2006G). The DNAH1 gene of patient 2 had a homozygous variant of c.2610G>A(p.W870X), which were inherited from his father and mother, respectively. According to American College of Medical Genetics and Genomics standards and guidelines, the c.2016T>G (p.Y672X) and c.2610G>A (p.W870X) varaints of DNAH1 gene were predicted to be pathogenic (PVS1+PM2+PM3+PP3).
Conclusion: The two patients of multiple morphological abnormalities of the sperm flagella may be caused by DNAH1 gene variant, which has resulted in primary male infertility.