Research Highlights

Defunct sperm pinned on mutated gene

Published online 13 January 2014

Biplab Das

More than 20 million men worldwide are infertile. Several gene mutations are known to impair the motility of sperm — a critical function in the race to fertilize the egg. A team of researchers from France and Tunisia, led by Pierre F. Ray from Université Joseph Fourier, France, has identified four mutations in the gene dynein heavy chain 1 (DNAH1), which codes a motor protein in the sperm's tail, that leads to infertility

The scientists performed a whole-genome scan on 20 infertile men with impaired sperm motility living in Tunisia, Algeria and Libya, publishing their results in the American Journal of Human Genetics.

The DNAH1 gene encodes a protein that forms a complex network of dynein proteins found in sperm flagella. By using diagnostic markers for dyneins, the researchers found that the mutations in DNAH1 led to a highly disorganized axoneme, the core structure of flagella. This resulted in abnormal flagella with 0–2% sperm motility in most of the studied patients.

"We hope to develop new therapies for infertile couples by introducing a functional protein in the testes of affected men," says Ray.


  1. Khelifa, M. B. et al. Mutations in DNAH1, which encodes an inner arm heavy chain dynein, lead to male infertility from multiple morphological abnormalities of the sperm flagella. Am. J. Hum. Genet. (2014) doi:10.1016/j.ajhg.2013.11.017