Scientists have identified a single mutated gene that causes Hajdu-Cheney syndrome (HCS), a disorder of the bones causing progressive bone loss and osteoporosis. The study, published online in Nature Genetics on March 6, 2011, gives vital insight into possible causes of osteoporosis and highlights the identified gene (NOTCH2) as a potential target for treating the condition. There are only 50 reported cases of HCS, of which severe osteoporosis is a main feature. Osteoporosis is a condition leading to reduction in bone strength and susceptibility to fractures. It is the most common bone disease, with one in two women and one in five men over 50 in the UK fracturing a bone because of the condition. This represents a major public health problem yet, until this study, possible genetic causes of osteoporosis have been poorly understood. The team of researchers, led by the National Institute for Health Research (NIHR) comprehensive Biomedical Research Centre (BRC) at King's College London and Guy's and St Thomas', set out to investigate the genetic cause of HCS in order to detect clues to the role genes might play in triggering osteoporosis. Using a cutting edge technique for identifying disease-causing genes, known as exome sequencing, the team was able to identify NOTCH2 as the causative gene using DNA from just three unrelated HCS patients. The team then confirmed their findings in an additional 12 affected families, 11 of whom had an alteration in the identical portion of the same gene. Senior author Professor Richard Trembath, Head of King's College London's Division of Genetics and Molecular Medicine and Medicine Director of the NIHR BRC, said: "Up until now, we knew very little about the genetic mechanisms of severe bone disease.Login Or Register To Read Full Story