Analysis Of Variants Of Unknown Significance In Atm

One of the deadliest cancers in the United States is ovarian cancer. Twenty percent of the women diagnosed with ovarian cancer will be found to have a germ line mutation in a cancer predisposition gene. As such the current standard of care of ovarian cancer is to be advised to seek genetic counseling and testing. Although genetic testing can increase the rate at which early stage ovarian cancer can be detected; however, often the results that come back are inconclusive. This is because many alleles that are found are classified as variants of unknown significance, in which their effect on the function of a gene is still unknown. Forty-eight women were studied by whole exome sequencing and six variants in the ATM gene were found and classified as variants of unknown significance. These variants were S49C, S333F, F1463C, N1853V, L2307F and V2540I. Also, two variants with truncating mutations were found in the same cohort. This implies that ATM is a major gene for predisposition to ovarian cancer. In order to determine the effects of SNP variants of unknown significance in ATM on its downstream signals, we will study the phosphorylation of ATM targets that occurs downstream of these variants and compare them to those that occur using both positive and negative controls. We will be looking at several different downstream targets including CHEK2, TP53, and H2AX as well as others. Furthermore, in order to determine the mechanism of signaling by ATM variants on the CHEK2 protein kinase, we will be using both CHEK2 knockdown and knockout cell lines to determine whether some of the downstream targets activated are dependent on CHEK2. This will provide more accurate genetic counseling and guidance for treatment of ovarian cancer patients as well as the hope of preventing it from occurring