[Show abstract][Hide abstract] ABSTRACT: Klinefelter syndrome and Y-chromosomal microdeletion analyses were once the only two genetic tests offered to infertile men. Analyses of aurora kinase C (AURKC) and DPY19L2 are now recommended for patients presenting macrozoospermia and globozoospermia, respectively, two rare forms of teratozoospermia particularly frequent among North African men. We carried out genetic analyses on Algerian patients, to evaluate the prevalence of these syndromes in this population and to compare it with the expected frequency of Klinefelter syndrome and Y-microdeletions. We carried out a retrospective study on 599 consecutive patients consulting for couple infertility at the assisted reproduction unit of the Ibn Rochd Clinique, Constantine, Algeria. Abnormal sperm parameters were observed in 404 men. Fourteen and seven men had typical macrozoospermia and globozoospermia profiles, respectively. Molecular diagnosis was carried out for these patients, for the AURKC and DPY19L2 genes. Eleven men with macrozoospermia had a homozygous AURKC mutation (79%), corresponding to 2.7% of all patients with abnormal spermograms. All the men with globozoospermia studied (n = 5), corresponding to 1.2% of all infertile men, presented a homozygous DPY19L2 deletion. By comparison, we would expect 1.6% of the patients in this cohort to have Klinefelter syndrome and 0.23% to have Y-microdeletion. Our findings thus indicate that AURKC mutations are more frequent than Klinefelter syndrome and constitute the leading genetic cause of infertility in North African men. Furthermore, we estimate that AURKC and DPY19L2 molecular defects are 10 and 5 times more frequent, respectively, than Y-microdeletions.
Full-text · Article · Aug 2014 · Asian Journal of Andrology
[Show abstract][Hide abstract] ABSTRACT: Infertility concerns a minimum of 70 million couples worldwide. An important proportion of cases is believed to have a genetic component, yet few causal genes have been identified so far. In a previous study, we demonstrated that a homozygous mutation (c.144delC) in the Aurora Kinase C (AURKC) gene led to the production of large-headed polyploid multi-flagellar spermatozoa, a primary infertility phenotype mainly observed in North Africans. We now want to estimate the prevalence of the defect, to improve our understanding of AURKC physiopathology in spermatogenesis and assess its implication in oogenesis. A carrier frequency of 1/50 was established from individuals from the Maghrebian general population, comparable to that of Y-microdeletions, thus far the only known recurrent genetic event altering spermatogenesis. A total of 62 patients were genotyped, all who had a typical phenotype with close to 100% large-headed spermatozoa were homozygously mutated (n = 32), whereas no AURKC mutations were detected in the others. Two homozygous females were identified; both were fertile indicating that AURKC is not indispensible in oogenesis. Previous FISH results had showed a great chromosomal heterogeneity in these patient's spermatozoa. We demonstrate here by flow cytometry that all spermatozoa have in fact a homogeneous 4C DNA content and are thus all blocked before the first meiotic division. Our data thus indicate that a functional AURKC protein is necessary for male meiotic cytokinesis while its absence does not impair oogenesis.
Full-text · Article · Feb 2009 · Human Molecular Genetics