Genetic syndromes with germline mutations associated with MBs [41,42,43] included Gorlin syndrome (heterozygous germline pathogenic variant in PTCH1 or SUFU) [44,45], CMMR-D syndrome (biallelic deleterious germline mutations in MMR genes (MLH2, MSH2, MSH6, and PMS2)) [46], Li-Fraumeni syndrome (germline mutation of TP53) [47,48], familial adenomatous polyposis syndrome (germline APC muttaion) [4,49], and Cowden syndrome (germline mutation of PTEN) [41,50]. The gene discussed is PMS1; the disease is Constitutional mismatch repair deficiency syndrome.