Racial variation in the O-acetylation phenotype of human colonic mucosa

O‐acetylated and non‐O‐acetylated sialoglycoproteins can be distinguished by the mPAS (mild periodic acid‐Schiff) histochemical technique. Individual adults show one of three different patterns of staining of large intestinal mucosa: uniformly mPAS‐positive, uniformly mPAS‐negative, or mPAS‐negative with scattered mPAS‐positive crypts. To test our hypothesis that these variations are the results of a single autosomal gene (oat) polymorphism, we have studied the frequency of the three patterns of staining in a total of 435 adult colon specimens from six geographically separate populations: British, South African blacks, Icelanders, Japanese, Hong Kong Chinese, and Bahrainis. The distribution of the three types of staining fell into two groups. In Japanese and Chinese, uniformly mPAS‐positive cases were much more frequent than uniformly mPAS‐negative cases; this distribution differed significantly (X2, P