Globozoospermia, characterized by round-headed spermatozoa without acrosomes, is a rare and severe teratozoospermia causing primary male infertility. Homozygous DPY19L2 deletions have been identified as the main cause of globozoospermia, blocking sperm head elongation and acrosome formation. Several previous studies showed a very different prevalence of DPY19L2 gene deletions among globozoospermic patients in cohorts with different sample sizes and in different ethnic background. And all the patients previously analyzed were mainly of European, North African and Middle Eastern origins. So far, only 11 different point mutations of the DPY19L2 gene have been reported. To investigate the prevalence of DPY19L2 gene mutations in Chinese patients with globozoospermia and whether we can identify new sequence variants in this study, we recruited a total of 16 globozoospermic patients. Excluding one of two brothers, molecular analysis for deletions and mutations in the DPY19L2 gene was performed on 15 genetically independent individuals. Four of the 15 genetically independent patients with globozoospermia were homozygous for the DPY19L2 deletion, 5 were homozygous for a point mutation including a nucleotide deletion c.1532delA (two patients), a multi-mutation consisting of a nucleotide deletion c.1679delT and a two-nucleotide deletion c.1681_1682delAC (c.[1679delT; 1681_1682delAC]) (one patient), a recurrent missense mutation R290H (one patient) and a missense mutation L330P (one patient). One additional patient had a heterozygous deletion in one allele but with no mutation identified in another allele. Overall, 60% of the patients (9/15) have a sequence variant of DPY19L2 in both alleles. This study confirms that the DPY19L2 mutations are the major cause of globozoospermia. Three novel point mutations and a recurrent missense mutation were found in this study, further broadening the spectrum of DPY19L2 mutations.
Keywords: DPY19L2; genetics of infertility; globozoospermia; point mutations.