A mutation in a gene called AURKC (Aurora Kinase C) has been identified in 14 infertile men of North African descent, reports a paper online this week in Nature Genetics. While deletions of some portion of the Y chromosome have been found in infertile men, this is a rare example in which a mutation in a single gene causes male infertility.
Estimates suggest that at least 80 million individuals worldwide are infertile. Pierre Ray and colleagues studied 14 men whose infertility seemed to have a similar origin. Their sperm were characterized by large heads, increased DNA content, and a variable number of flagella-- the whip-like tails that propel the sperm. A genome-wide scan identified a mutation in AURKC that severely truncates the protein. AURKC encodes an enzyme that phosphorylates other proteins, and the authors show that the mutation abolishes this activity. An analysis of the genomic region around AURKC shows that these individuals have other markers in common, suggesting that this mutation appeared in a North African common ancestor approximately 1,500 years ago. The authors note that a larger study of the prevalence of this mutation in North Africans is now warranted.
Pierre Ray (University Hospital of Grenoble, France)
Abstract available online.
(C) Nature Genetics press release.
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