Taiwan researchers locate gene causing neuromuscular disorder

 2013/04/08 22:32:24 Taipei, April 8 (CNA) A team of researchers from two medical centers in Taipei has discovered a gene, identified as GNB4, that triggers hereditary motor sensory neuropathy (HMSN) if its DNA chain is incomplete.The group discovered the gene after spending years studying a family whose members suffered from HMSN, a heterogeneous group of various inherited neuromuscular disorders.Lee Yi-chung, an attending physician at Taipei Veterans General Hospital's Neurological Institute, said Monday that a man surnamed Lin was diagnosed at the hospital several years ago with HMSN, also known as Charcot-Marie-Tooth Disease or Progressive Peroneal Muscular Atrophy.Lee said that according to the patient, his leg muscles began showing signs of atrophy at the age of 13, and the atrophying process lasted until he was 46 years old, when he could no longer walk.Several members of Lin's family also showed symptoms of the muscular disorders, including deformation of their arms and legs and weakness in their leg muscles, Lee said, noting that many HMSN patients end up using wheelchairs as the disorders progress.Before checking into Taipei Veterans General Hospital, Lin had visited many doctors and specialists around Taiwan after he was no longer able to walk, but they all failed to find the cause of his illness, Lee said.With the participation of Lin and his family, the research team, composed of National Yang Ming University's Brain Research Center and Taipei Veterans General Hospital's Neurological Institute, found the gene in the patients that induced the disorders after years of research.HMSN is an inherited, progressive disease of the nerves with weakness and numbness more pronounced in the legs than the arms. The nerves stop sending messages to different areas of the body, such as the hands and feet, because the nerve cells deteriorate.

The muscles in the hands and feet get weak because they no longer receive messages from the nerves and are therefore not used, according to the American Association of Neuromuscular and Electrodiagnostic Medicine.According to Lee, HMSN often appears when patients are in their childhood or when they reach puberty. One out of every 2,500 people suffer from the ailment, and at least 9,000 people in Taiwan have it, he said.Because few physicians in Taiwan know about the illness, many patients have not been properly diagnosed, Lee said.The finding of the Taiwanese team was published in the American Journal of Human Genetics on March 7.(By Lung Rui-yun and Elizabeth Hsu)