scientists discover genetic defect to Leigh syndrome

A team of Australian and U.S. scientists on Wednesday said they discovered a genetic defect, which can lead to Leigh syndrome, a rare disorder which affects the central nervous syndrome. The scientists tested more than 1000 genes by encoding proteins active in two individuals who suffer from the illness. They used a new technique known as next-generation DNA sequencing to examine the genes. The gene they discovered encodes an enzyme which is found in the mitochondria which are subsets of cells. Without this enzyme the mitochondria do not translate proteins efficiently, and this then causes Leigh syndrome. According to David Thorburn, from the Murdoch Children's Research Institute in Melbourne, the discovery shows the enormous potential of the new technology. "These findings demonstrate the ability of sequencing technologies to improve diagnosis," Professor Thorburn said in a statement released on Wednesday. "Although it isn't clear in the case of Leigh syndrome whether the precise molecular diagnosis will necessarily lead to therapies, the current findings represent a meaningful service." He added that diagnosis of the disease along with its specific genetic cause can also be informative about the risk a couple has of having another affected child. The diagnostic information can help in decisions about whether and how to pursue alternative means of having children, for instance through the use of donor sperm or eggs. The research team consisted of scientists from Australia's Murdoch Institute as well as the Broad Institute in the U.S. In Leigh syndrome, infants are born apparently healthy only to develop movement and breathing disorders that worsen over time, often leading to death by the age of three. The problem is that the mitochondria responsible for powering their cells cannot keep up with the demand for energy in their developing brains.