The Fugates, a family that lived in the hills of Kentucky, commonly known as the "Blue Fugates" or the Blue People of Kentucky, are notable for having been carriers of a genetic trait that led to the disease methemoglobinemia, which gives sufferers blue-tinged skin.
Ancestry
French-born Martin Fugate, orphaned as a child, settled near Hazard, Kentucky, circa 1820. Because of the remote rural area in which they and other nearby families had settled, there was a very high level of consanguinity in marriage between families. His wife Elizabeth Smith was a carrier of the recessive methemoglobinemia (met-H) allele, as was a nearby clan with whom the Fugates intermarried. As a result, many descendants of the Fugates were born with met-H.
Descendents with the disease gene continued to live in the areas around Troublesome Creek and Ball Creek into the 20th century, eventually coming to the attention of the nurse Ruth Pendergrass and the hematologist Madison Cawein III, who made a detailed study of their condition and ancestry.
Cawein treated the family with methylene blue, which eased their symptoms and reduced the blue coloring of their skin. He eventually published his research in the Archives of Internal Medicine in 1964.
As travel became easier in the 20th century, and families spread out over wider areas, the prevalence of the recessive gene in the local population reduced, and with it the probability of inheriting the disease.
Benjamin Stacy, born in 1975, is the last known descendent of the Fugates to have been born exhibiting the characteristic blue color of the disease, and lost his blue skin tone as he grew older.
It has been speculated that some other American sufferers of inherited methemoglobinemia may also have had Fugate ancestors, but searches for direct links have so far proved inconclusive.