Eskimo, Canadian

Finally, polymorphisms associated with arylamine N-acetyltransferase (NAT2) may result in slow acetylators. The slow-acetylator phenotype is present in 50-70% of the population in Western countries and is associated with several drug-induced side effects. The frequency of the slow-acetylator phenotype rises to 80% in Egyptian and certain Jewish populations however, the frequency drops to 10% or 20% among Japanese and Canadian Eskimos. 

The proportion of slow acetylators and the frequency of the slow acetylator gene has been determined in many different populations (see Table VIII). Frequencies of the slow acetylator phenotype range approximately from 5% in Canadian Eskimos (Armstrong and Peart, 1960) up to approximately 83% in Egyptians (Hashem et al., 1969). It can be seen from Table VIII that populations of Asiatic origin with few exceptions have low frequencies of the slow acetylator gene compared to populations of African and European origin and to Jewish populations which have been surveyed. 

Our blood type is determined by a gene that is present on chromosome 9, near the end of the long arm. There are four general blood types A, AB, B, and O. Some of these are intermixable while others are not. For instance, A blood from a person is compatible with A and AB B with B and AB AB with only AB and O blood is compatible with all of the blood types—a person with type O is then a universal donor. These compatibility scenarios are not race-related. For all but the native Americans who have almost totally type O, the rest of us have about 40% type O another 40% type A 15% type B and 5% type AB. (Some of the Eskimos are type AB or B and some Canadian tribes are type A.) A and B are codominant versions of the same gene and O is the recessive form of this gene. 

Ethnic Differences. Ethnic differences are basically genetic, with different proportions of "normal" and slow metabolizers observed in different populations. However, the influence of environmental factors such as nutrition and lifestyle cannot be excluded. An early example was the phenotyping of slow and fast acetylators of isoniazid. Slow acetyla-tors (primarily caused by decreased activity of the NAT2 enzyme) exhibited a pronounced ethnic difference, e.g., 60% slow acetylators in Europe, —50% in Africa, —15% in China and Japan, and 5% in Canadian Inuit (Eskimo s) (117). It is now recognized that ethnicity and polymorphism are involved in a number of phase I and phase II enzymes, including CYP, FMO, methyltransferases, sulfotransferases, glucuronyltransferases, and acetylation. 

Asiatic origin Eskimos, Canadian 216 0.05 0.22 Armstrong and Peart... 

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