The frequency of "rare" protein variants in Marshall islanders and other Micronesians.

Blood specimens from a sample of 373 Marshall Islanders were studied with reference to variants of 23 serum proteins and erythrocyte enzymes. Six of the traits studied exhibited genetic polymorphisms (adenosine deaminase, phosphoglucomutase1, acid phosphatase, 6-phosphogluconate dehydrogenase, haptoglobin, and group specific component). There were in addition four "rare" variants (albumin, transferrin, lactate dehydrogenase, and galactose-1-phosphate uridylyltransferase) involving nine persons, among 8,503 determinations. The frequency of rare variants in Micronesians was compared with the frequencies in West European Caucasians and Amerindians. There are many difficulties in such comparisons, and although the observed values for the three ethnic groups differ by a factor of three (the Micronesians exhibiting the lowest frequency), it is felt that no firm conclusions concerning differences between ethnic groups can be drawn at this time.