EPCAM and Leigh syndrome: LS is a hereditary, cancer-prone syndrome caused by germline pathogenic variants (PVs) or likely pathogenic variants (LPVs) in the DNA-mismatch repair (MMR) pathway genes (MLH1, MSH2, MSH6 and PMS2) or the epithelial cell adhesion molecule (EPCAM) gene [4,5,6,7,8].