Fugates of Kentucky

I read from Yahoo! News articles about the Fugates of Kentucky and was greatly amazed that there really exist blue people. What I only knew and have seen in real life are those so-called "blue baby"[1], who are actually have cyanotic heart lesions, such as
  • Persistent Truncus Arteriosus
  • Transposition of the great vessels
  • Tricuspid atresia
  • Tetralogy of Fallot
  • Tetralogy of Fallot.


Its other symptoms include Methemoglobinemia[2], a disorder characterized by the presence of a higher than normal level of methemoglobin (metHb) in the blood. Other insults in neonates, such as respiratory distress syndrome, can also produce a "blue baby syndrome," although like methemoglobinemia, these are not structural lesions and are not regarded by most doctors as true "cyanotic lesions."

Image source: Wikipedia

I am not into a medical profession or to any related fields but I just want to know how and why these blue people acquired their "blue" attributes".

Fugates of Kentucky: Skin Bluer than Lake Louise (ABC News)
The origin of these people afflicted with these odd skin color was traced back to Martin Fugate, a French orphan who settled in Eastern Kentucky together with his redheaded American bride[3]  circa 1800.

Martin's great-great-great great grandson, Benjamin "Benjy" Stacy, inherited his dark blue skin that frightened maternity doctors after the boy's birth in 1975. The boy was rushed to a medical clinic in Lexington. When the transfusion was being readied, Benjy's grandmother asked the doctors if they have heard about the "blue Fugates of Troublesome Creek". Benjy's father, Alva Stacy, comes form the bloodline of Martin Fugate and that made the doctors to conclude that the boy's unusual color was inherited from generations back.


The Fugates offspring had a genetic condition called Methemoglobinemia and was passed down from one generation to the next generation and through intermarriage. Martin Fugates' wife was a carrier of the recessive methemoglobinemia (met-H) gene, as was a nearby clan with whom the Fugates intermarried. As a result, many descendants of the Fugates were born with met-H.[4]

Benjy Stacy is one of the last of the blue Fugates. With Fugate blood on both his mother's and his father's side, the boy could have received genes for the enzyme deficiency from either direction. Because the boy was intensely blue at birth but then recovered his normal skin tones, Benjy is assumed to have inherlted only one gene for the condition. Such people tend to be very blue only at birth, probably because newborns normally have smaller amounts of diaphorase. The enzyme eventually builds to normal levels in most children and to almost normal levels in those like Benjy, who carry one gene.[3]

Image source: The Blue People of Troublesome Creek

References: 
  1. Blue Baby Syndrome
  2. Methemoglobinemia
  3. The Blue People of Troublesome Creek 
  4. Methemoglobinemia Carriers