Cystic fibrosis, an inherited disease that causes respiratory and digestive problems, may also lead to infertility among women, according to breakthrough findings by Chinese University. The research was carried out by Chan Hsiao-chang, director of the university's epithelial cell biology research centre, and her team and it is published in the latest Nature Cell Biology international journal. It has already been established that most men with cystic fibrosis, which affects about one in 2,000 westerners, are infertile. The condition causes coughing and wheezing and in severe cases can be fatal. But it is 'very rare' among the Chinese population and there is no established medical finding about its prevalence, according to Professor Chan. She said the condition was mainly caused by mutation in a protein called the transmembrance conductance regulator. This mutation lowers the sperm's and the egg's fertilising abilities inside the uterus. 'A number of critical reproductive events, such as sperm capacitation, are known to occur in the female reproductive tract,' Professor Chan said. 'The mutation impairs the sperm's fertilising ability. 'The present finding not only provides better understanding of the cause for reduced female fertility in cystic fibrosis but also enables better management of assist-reproductive technologies for CF women as well as other CF-related infertility.' She said the findings were significant in identifying one of the causes of infertility. Though in vitro fertilisation was a solution, she added that more medical research had to be done to explore cheaper and more convenient alternatives.