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Hello: We absolutly do see blacks with PD....not as many as other ethnic groups but there out there. Chinese also get less pd then whites and tend to fit in between whites and blacks....this trend follows approx. levels of skin pigmentation. Whites have the least skin melanin and get the most pd....blacks have the most skin mel. and have the least pd, orientals fall in between. This is not a new observation. Neither is the eye color story. The best available hypothesis is that the skin pigment acts as a trap for neurotoxins known and unkown, MPTP is the best example. MPTP and manganese target the nigra by binding to the neuromelanin. Now, very few (ca. 1000) people ever got pd from mptp exposure, however, according to the model, there are believed to be other neurotoxins capable of this same sort of melanin binding. What concerns me is that if one wanted to get a grant to identify a new carcinogen in tobacco smoke that scientist would have little trouble getting funded....its a low risk project....low risk because one would probably succeed at adding to a list of many hundreds of cancer causing substances in tobacco and tobacco smoke. Try to get a grant to identify the chemicals in rural well water that may account for the epidemiological observation that there is a significant association between drinking rural well water and getting PD. It would be very tough going. Oh well....back to pigmentation. The melanin in the skin is made from the amino acid tyrosine, not dopamine as it is in the brain. Even so, it has an outstanding capacity to bing the same substances as nigral melanin, hence it may afford some protection against PD (not a new hypothesis at all). Regarding associations of pd with vitiligo....this is very interesting, however I know of no studies to substantiate a relationship. Should one be conducted? You bet. Will one be conducted? FUNDING is the limiting factor. Jeffrey M. Tosk, Ph.D. ([log in to unmask])