HANGZHOU - An international research team led by Chinese scientists have found a new gene that can cause congenital blindness.

Congenital blindness is a kind of autosomal recessive inherited retinal degenerative disease. About 70 percent of the cases are caused by the mutation of one of the 17 disease-causing genes which have already been discovered, while the causes of the rest 30 percent have not been found yet.

After studying cases where the cause of disease was still unknown, the researchers, led by Qi Ming, a professor with Zhejiang University, concluded that a gene called "NMNAT1" is a disease-causing gene for the congenital eye disease.

The research team is made up of scientists from countries including China, the United States, Brazil, Canada and Australia.

The NMNAT1 gene can protect the light receptor cells in the retina and is also of great importance for the nerve cells and the heart, kidney and liver tissue in human body.

The mutation of the gene can cause a kind of congenital blindness called the Leber congenital amaurosis (LCA), Qi said, adding that the mutation of NMNAT1 also harms the patients' nerves and some organs.

Gu Yangshun, an expert with the First Affiliated Hospital of Zhejiang University, said that there are over 600 kinds of hereditary eye diseases which are hard to diagnose, and genetic testing is a key measure to diagnose the diseases.

Besides Qi Ming's team, three other teams led by Chen Rui from Baylor College of Medicine in Houston, Josseline Kaplan and Jean-Michel Rozet from France and Eric Pierce from Massachusetts Eye and Ear Infirmary in Boston have also found that particular disease-causing gene, and their essays were published together in the Nature Genetics on July 29.

Experts said identifying of the gene had provided a way to treat the disease, since the rapid development of molecular biology has made it possible to prevent and treat the hereditary diseases from the core via the technology of genetic diagnose and genetic treatment.

Qi said that in the US and Europe, some scientists have mastered the technology to identify the location of the disease-causing gene in the patients' eyes and inject good genes there to promote the healthy development of the organs.

Within three years, China will be able to use this kind of treatment as well to treat the congenital eye diseases and the identifying of the ? NMNAT1 gene will be of great significance for the kind of treatment, Qi said.