Learn about the genetic abnormality that led to blue skin in one Kentucky family.
The "Blue People" were descendants of Martin Fugate, a French immigrant to Kentucky. He had a recessive gene that limited or stopped the body's production of the enzyme diaphorase.
Diaphorase breaks down methemoglobin into hemoglobin in red blood cells. When the enzyme is not present, a disproportionate amount of methemoglobin remains in the blood, giving the cells a bluish tint, rather than the normal pink associated with Caucasians. The condition is strictly one of pigment and does not deprive the person of oxygen.
Despite bluish color, there are no known health risks associated with the deficiency. Fugate's family suffered from the condition because of excessive inbreeding. When both spouses had the recessive gene, their children would be blue. As the family became mobile following World War II and moved out of their Kentucky valley, the inbreeding ceased. As of 1982 there were only two to three members of the family with the condition.