Supplementary Material for: ATM Variant as a Cause of Hereditary Cutaneous Melanoma in a Spanish Family: Case Report

<b><i>Introduction:</i></b> Ataxia-Telangiectasia Mutated (ATM) is a cancer predisposition gene; carriers of germline pathogenic variants have an increased risk of developing malignancies, including breast, prostate, pancreatic, and ovarian cancer. Most ATM variants are of uncertain significance. Findings from genome-wide association studies (GWAS) suggest that ATM may be a low-risk melanoma susceptibility locus. <b><i>Case Report:</i></b> We report the case of a Hispanic family whose members who have presented cutaneous melanoma have been found to be carriers for the ATM pathogenic variant c.3747-1G&gt;C (rs730881364), one of whom was diagnosed at 24 years old. <b><i>Discussion:</i></b> We describe for the first time the possible clinical association between ATM (c.3747-1G&gt;C) and familial melanoma. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site, assuming a variant that entails loss of functionality that is probably pathogenic and related to oncogenesis. However, we cannot exclude that cutaneous melanoma in both members and at an early age is the result of chance, environmental interaction, other uncontrolled external factors, or the interaction of other genetic alterations other than the ATM variant described in this study.