 Some humans have very little or no melanin synthesis in their bodies, a condition known as albinism.Because melanin is an aggregate of smaller component molecules, there are many different types of melanin with different proportions and bonding patterns of these component molecules.Both pheomelanin and eumelanin are found in human skin and hair, but eumelanin is the most abundant melanin in humans, as well as the form most likely to be deficient in albinism.