Genetic and demographic aspects of Nova Scotia Niemann-Pick disease (type D)

All known cases of Nova Scotia Niemann-Pick Disease (type D) were traced to a couple born in Nova Scotia in the late 1600s. It is speculated that this disease is the result of a single mutation in one of the ancestors of Yarmouth County French Acadians. In the district where most affected children lived, the heterozygote frequency was estimated to be between 10% and 26%.