Meet the Fulgates, a family of people with blue skin that lived in Kentucky for many generations. They gained their blue skin through a combination of inbreeding and a rare genetic condition known as methemoglobinemia.
Methemoglobinemia is a blood disorder in which an abnormal amount of methemoglobin (a form of hemoglobin) is produced
The genetic defect can occur when a person has a deficiency in the enzyme called cytochrome-b5 methemoglobin reductase, which is responsible for recessive congenital methemoglobinemia. They also lacked the enzyme diaphorase in their red blood cells, normally diaphorase converts methemoglobin back to hemoglobin.
Methemoglobin can develop blue skin without any negative symptoms. Most of the blue Fugate family members never suffered any health effects and lived into their 80s and 90s. It was discovered that there was inbreeding within the family that contributed to the high number of blue offspring.