Abstract: This paper presents the results of an examination phenotypes within two blood group polymorphisms to determine the effect, if any, of blood groups on anthropometric traits.
The examination is based on the data obtained from 404 subjects. All the subjects, belonging to Li nationality, are enrolled middle school students and the students at Guangdong College of Minorities. ABO, MN blood groups were determined and 35 features were simultaneously surveyed for all the subjects. The distributions of MN blood types in the ABO blood group system were also examined in this paper.
It is clear by statistical analyses that blood group phenotypes show some noticeable differences with regard to average values of anthropometry. Judging from 35 physical traits as a whole, there exist significant differences among the blood group phenotypes, since the X2p(2df)s are less than 0.05 by rank order analysis. We may infer, in terms of our study only, that some correlations exist between blood group phenotypes and anthropometric traits. In MN system, the most striking feature about the results is the consistency of lower total rank in the samples of MN phenotypes for both males and females. It is deduced on account of the allelic equivalence of the gene M and N that the lower anthropometric measurements of the MN phenotype are related to the MN heterozygote. In ABO system, the significance of the results is clouded by our inability to distinguish, for A and B, the hemozygotes from the heterozygotes.
We have made use of t test to compare the distributions of MN blood group phenotypes in the ABO blood group system. The results show that they are not related to ABO groups. It is concluded that no hereditary relation exists between MN system and ABO system, that is to say, MN blood group factors are hereditarily independent from ABO factors. This conclusion is identical with that established by other authors.

Key words: ABO blood groups; MN blood groups; Anth ropometry; Statistic analyses