The first authors identified a case of osteogenic sarcoma in a member of a family affected by LS underlying MSH2 pathogenic variant (exon 4 splice site mutation TAG3 GAG, respectively), while the second group found a case of lower-leg osteosarcoma in a 15-year-old female carrying a MLH1 (c.1276C>T) pathogenic variant [72,73]. This evidence concerns the gene MLH1 and osteosarcoma.