Massachusetts General Hospital researchers, in collaboration with colleagues at the University of California-Irvine, determined defects in a gene called PROK2 in human siblings with two different forms of infertility. The University of California-Irvine team previously found mice lacking PROK2 had abnormal olfactory structures and disrupted circadian rhythm.

"We have demonstrated that PROK2 signaling is a novel pathway that is critical to the development of neurons that control the reproductive system -- findings that should enable better understanding of human reproduction," said lead study author Dr. Nelly Pitteloud.

The report is available in the early online edition of the Proceedings of the National Academy of Sciences.