Carbonic anhydrase-I polymorphism in a Philippine aboriginal population.

Polymorphism of carbonic anhydrase-I (CA1) was found by electrophoresis in an aboriginal group of Mindanao, Philippines, with a remarkably high frequency of variant types. The frequency of the variant allele was estimated at .256. The variant isozyme designated CA1 3Negrito (CA1 3N) is electrophoretically indistinguishable from the "Guam" variant and may be regarded as a potential anthropological marker in the Western Pacific.