(HealthDay News) — Specific ataxia telangiectasia mutated (ATM) gene mutations that increase the hereditary risk of familial pancreatic ductal adenocarcinoma have been identified, according to a study published online Dec. 29 in Cancer Discovery.
Noting that the ATM protein is a serine/threonine kinase known to be involved in the repair of double-strand DNA breaks, Nicholas J. Roberts, M.D., of the Johns Hopkins Kimmel Cancer Center in Baltimore, and colleagues sought to identify the causative genes to explain a familial cluster of pancreatic cancer. Whole-genome sequences from 16 individuals from six families and whole-exome sequences from an additional 22 individuals from 10 families with familial pancreatic cancer were used to identify those with deleterious mutations. Each family included at least three members with pancreatic ductal adenocarcinoma. Known predisposition genes were eliminated, as no mutations in these genes were observed. The coding region of the ATM gene was then sequenced for an additional 166 familial pancreatic cancer probands and 190 spouse controls.
The researchers found that, overall, four of 166 familial pancreatic cancer probands (2.4 percent) carried deleterious ATM mutations. Taking into account only those families with three or more cases, four of 87 probands (4.6 percent) carried a deleterious, functional mutation in the ATM gene. Under natural conditions, these mutations are associated with a recessive disease phenotype.
“The identification of deleterious ATM mutations in probands has substantial implications for risk assessment and surveillance in other family members. Moreover, because ATM is a key participant in DNA repair, it is possible that new therapeutics based on synthetic lethal interactions can be developed to treat these patients with pancreatic ductal adenocarcinoma, as has been accomplished for patients with BRCA gene mutations,” the authors write.