And if you’re at higher risk of developing vitiligo, the results of the study, by the University of Colorado School of Medicine, indicate you might also be more vulnerable to developing other autoimmune diseases such as rheumatoid arthritis. The study focused mainly on vitiligo but its findings are also important for research into the skin cancer melanoma.
The Colorado study, published in the journal Nature Genetics, involved nearly 3,000 Americans, all of non-Hispanic European ancestry, who had vitiligo and noted their eye colour. Around 52% of Americans of the same ancestry will have blue or grey eyes, 27% brown and 22% hazel or green.
However, the results from the vitiligo patients showed a marked variance in eye colour from the norm, namely that only 27% had blue or grey eyes, 30% had green or hazel but 43% had brown eyes. The findings demonstrate that those with blue eyes are less likely to have vitiligo while those with brown eyes may face a lowered risk of developing melanoma.
The immune system turns on the body when a person develops vitiligo, attacking the pigment cells in the skin. Scientists believe the condition is actually a hyper version of the normal way the immune system would destroy the cells that cause melanoma.
And because the immune system is already deficient, those with vitiligo have an increased risk of going on to develop other autoimmune diseases such as rheumatoid arthritis, lupus, thyroid disease and type 1 diabetes.
Further research into what causes vitiligo could have benefits for scientists trying to discover what triggers other autoimmune diseases.