ناسیاه‌گرایی

right|thumb|Often called "Albinism|albino", this amelanistic [[Burmese python owes its yellow color to unaffected carotenoid pigments.]] Amelanism (also known as amelanosis) is a pigmentation abnormality characterized by the lack of pigments called melanins, commonly associated with a genetic loss of tyrosinase function. Amelanism can affect fish, amphibians, reptiles ,(including birds) and mammals including humans. The appearance of an amelanistic animal depends on the remaining non-melanin pigments. The opposite of amelanism is melanism, a higher percentage of melanin.