Gene therapy breakthrough for male infertility

Scientists from the Salk Institute in California have used gene therapy to correct a form of infertility in male mice. The study is reported in the Proceedings of the National Academy of Sciences. The mice in the study had mutations in a gene called KL2 in the Sertoli cells - cells that are found in the testes and aid the production and development of sperm cells.

Mice with the gene mutation failed to produce sperm. Inder Verma, professor of genetics at the Salk Institute, who led the research team said that in humans, 'the overwhelming majority of male infertility cases arise from inability to make sperm cells. Most of those cases are not due to defects in sperm cells themselves, but in other cells that support sperm production'. It is estimated male infertility accounts for about a third of all cases of infertility in humans. The researchers believe that about 70 to 80 per cent of these cases may be able to be effectively treated using gene therapy.

A virus was used to introduce working versions of the KL2 gene to the infertile mice. This restored sperm production in all of the animals which underwent the therapy. Sperm cells from the treated mice were tested for viability and embryos created using ICSI (intracytoplasmic sperm injection) appeared to develop normally, some resulting in the birth of healthy pups.