Recent research by a team of scientists at the University of Toronto has uncovered new information about the genetic causes of Amyotrophic Lateral Sclerosis (ALS), more commonly known as Lou Gehrig’s disease, which could possibly lead to earlier detection of genetic predisposition to ALS.
The study, which was headed up by Professor Ekaterina Rogaeva and Professor Lorne Zinman, was based around three generations of the same family. Although both the grandparents and the parents were healthy and showed no signs of the disease, four of the five adult children exhibited the genetic mutation commonly associated with ALS.
Only 10% of sufferers have genetically acquired ALS
In as many as 90% of patients the cause of Lou Gehrig’s is unknown, with the remaining 10% being attributed to genetic factors which have been passed down by the parent. Until recently, scientists have believed that those suffering from genetically acquired ALS have a parent with the disease. However, this new study turns that theory on its head, as none of the parents or grandparents had ALS.
The study was able to identify the number of unstable repeated DNA sequences
While it is known that an unstable repeated DNA sequence is commonly associated with ALS, the number of repeats which would need to be present to cause the disease is not known. In the study, the father exhibited 70 repeats, which is not sufficient to cause ALS, while the mutation had expanded to over 1000 repeats in the affected children.
This brings new hope for the development of a genetic test to identify predisposition to ALS
Professor Zinman hopes that the information gleaned from their research, which was published in the June 4th edition of the American Journal of Human Genetics, will offer a way to develop a genetic test to identify whether a parent is likely to pass on the mutation that could cause ALS to their children.
The team from the University of Toronto plan to expand their research to include other multi-generational families, together with a sample of unaffected parents, to further enhance their understanding of how these repeated sequences can predict a genetic predisposition to ALS.