Although genetic mutations are commonly associated with cancer and other harmful diseases, not all mutations are harmful. In fact, most of them are harmless. Even in rare genetic disorders, the mutations that actually stimulate the disease are just one or two out of the possible tens of thousands. However, distinguishing between these harmful and harmless mutations in this pool of thousands has long been a challenge for scientists.

A new tool developed by Rockefeller University scientists aims to make this process easier by predicting the chances that any given human gene is likely to contain a disease-causing mutation. The team of researchers hopes that this tool will eventually be utilized by researchers in order to sift through genetic data easier and filter out irrelevant genes.

"To find a needle in the haystack, it helps to get rid of some of the hay," Yuval Itan, the study's senior author, said in a press release. "Filtering out the noise, the genes that pollute the data, is crucial."

The researchers used genome analysis and discovered that approximately 58 percent of rare genetic variants can be found in just 2 percent of human genes. This observation stimulated the development of their tool, the Gene Damage Index, due to their reasoning that genes that are typically mutated in the average person are not likely to cause rare diseases because their variations are likely to be found in healthy people.

The Gene Damage Index metric takes into account the extent of mutation to each gene in the general population, as well as how important the given gene is to a specific disease group, such as autism, cancer and Mendelian disorders.

"With this method, up to 60 percent of the irrelevant variants can be removed," Itan said. "The Gene Damage Index will help scientists more easily sort through the large amounts of data produced by next-generation sequencing."

The findings were published in the Sep. 22 issue of the Proceedings of the National Academy of Sciences.