A gene mutation that causes formation of abnormally shaped sperm results in male infertility, according to a report in the advance online publication of Nature Genetics.

The mutation, which is located in the aurora kinase C gene (AURKC), is associated with large-headed sperm with too many sets of chromosomes and multiple flagella, or tails, which allow the cells to move. Previous research identified only deletions of the Y chromosome as a cause of altered sperm formation, the authors explain.

Dr. Pierre F. Ray from Centre Hospitalier Universitaire de Grenoble, France and associates performed a gene scan on 14 infertile men of North African descent. The subjects all had a deletion of two copies of the amino acid cytosine in AURKC, whereas there were no mutations detected in 100 chromosomes from European men and only 1 in 100 chromosomes from fertile North African men

Despite having this gene-related infertility, men with this deletion showed no obvious physiological or anatomical defects, the report indicates. Moreover, men with only one copy of the gene mutation were not infertile.

Ray and his colleagues “intend to carry out a larger epidemiological study of both fertile and infertile North Africans to estimate the prevalence of (the AURKC mutation) and evaluate the impact it may have on the reproductive fitness of this population.”

SOURCE: Nature Genetics, April 15, 2007.