“Many genes are essential for sperm production but, surprisingly , very few isolated genetic changes that show a failure of sperm production in humans , “says Ken McElreavey , researcher at the Pasteur Institute in France and author of the study .

McElreavey group sequenced the gene NR5A1 in 315 healthy men who were seeking treatment for infertility, and who had an unexplained inability to produce sperm. The research, published today in the American Journal of Human Genetics, Identified seven men with severe sperm production problems that had changes in this gene.

In the men studied , mutations were associated with altered levels of sex hormones , and in one case , with mild abnormalities in the cellular structure of the testes. There were no similar genetic alterations in more than 2,000 control samples.

These results suggest that changes in NR5A1 are not only associated with severe and obvious defects of player development . ” About 4 % of men with inability to produce sperm, which can not be explained otherwise, have mutations in the NR5A1 gene , “says Anu Bashamboo , another author who also works at the Pasteur Institute .

The data also suggest that some forms of male infertility can be an indicator of a slight anomaly in testicular development . Experts emphasize the need for careful clinical investigation of men with symptoms of infertility and abnormal levels of sex hormones.

The gene NR5A1

The NR5A1 gene encodes a key protein called steroidogenic factor 1 regulates sexual development during fetal , prepubertal and adult. Some previous work had shown that NR5A1 mutations are associated with severe defects in the development of the testes or ovaries , as well as significant abnormalities of the male external genitalia .

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References:
McElreavey et al. : “Human Male Infertility Associated with Mutations in NR5A1 Encoding steroidogenic factor 1. ” American Journal of Human Genetics, October 8, 2010 .

Source: SINC