In our study, we focused on 17 established cancer predisposition genes including ATM (MIM 607585), BARD1 (MIM 601593), BRCA1 (MIM 113705), BRCA2 (MIM 600185), BRIP1 (MIM 605882), CDH1 (MIM 192090), CHEK2 (MIM 604373), MLH1 (MIM 120436), MSH2 (MIM 609309), MSH6 (MIM 600678), PALB2 (MIM 610355), PMS2 (MIM 600259), PTEN (MIM 601628), RAD51C (MIM 602774), RAD51D (MIM 602954), STK11 (MIM 602216), and TP53 (MIM 191170), for which MLPA assays were available for the verification of in silico predicted CNVs. The gene discussed is CHEK2; the disease is cancer.