Though it is challenging to estimate to frequency in the population, there are likely over 1,000 multigenerational families worldwide with LFS. To date, inquiries on the LFS Association website have arrived from 172 countries.
There is no evidence of ethnic or geographic disparity in the occurrence of LFS, but a uniquely high prevalence of LFS has been reported in southern and southeastern Brazil. The population with LFS in this area has been associated with a highly specific variant of the TP53 referred to as R337H. Having this particular alteration in the region led researchers to suspect one point of origin, and family lineages were traced to a common ancestor who migrated long ago from Portugal. Interestingly, though, as opposed to the 90% lifetime risk of developing cancer in most people with LFS, the population in Brazil with this “founder mutation” has roughly a 60% lifetime risk of cancers, which have relatively favorable survival rates.