The hereditary predisposition to cancer dates historically to interest piqued by physicians as well as family
members wherein striking phenotypic features were shown to cluster in families, inclusive of the rather grotesque
cutaneous findings in von Recklinghausen’s neurofibromatosis, which date back to the sixteenth century. The
search for the role of primary genetic factors was heralded by studies at the infrahuman level, particularly on
laboratory mouse strains with strong susceptibility to carcinogen-induced cancer, and conversely, with resistance
to the same carcinogens. These studies, developed in the 19th and 20th centuries, continue today. This article
traces the historical aspects of hereditary cancer dealing with identification and ultimate molecular genetic
confirmation of commonly occurring cancers, particularly of the colon in the case of familial adenomatous
polyposis and its attenuated form, both due to the APC germline mutation; the Lynch syndrome due to mutations
in mismatch repair genes, the most common of which were found to be MSH2, MLH1, and MSH6 germline
mutations; the hereditary breast-ovarian cancer syndrome with BRCA1 and BRCA2 germline mutations; the
Li-Fraumeni (SBLA) syndrome due to the p53 mutation; and the familial atypical multiple mole melanoma in
association with pancreatic cancer due to the CDKN2A (p16) germline mutation. These and other hereditary
cancer syndromes have been discussed in some detail relevant to their characterization, which, for many
conditions, took place in the late 18th century and, in the more modern molecular genetic era, during the past two
decades. Emphasis has been placed upon the manner in which improved cancer control will emanate from these
discoveries.