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 result 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 (chi 2, P < 0.001) from that in non-Sino-Japanese, where the uniformly mPAS-positive phenotype was much less frequently found than the uniformly mPAS-negative phenotype. In neither of the groups did the frequency of the three phenotypes differ significantly from that predicted for a single gene polymorphism by the Hardy-Weinberg law. The variation in staining patterns between populations is consistent with variation in frequency of a single polymorphic autosomal gene (oat) controlling O-acetylation of sialic acid, probably by an O-acetyl transferase enzyme. Loss of function mutation in the high acetylator gene (oata) in a colonic crypt stem cell in heterozygous individuals would account for the scattered discordant crypts. Gene frequencies for a variety of enzymes differ between the Sino-Japanese and non-Sino-Japanese races.(ABSTRACT TRUNCATED AT 250 WORDS)
Campbell
F
F
Department of Pathology, University of Wales College of Medicine, Cardiff, U.K.
Appleton
M A
MA
Fuller
C E
CE
Greeff
M P
MP
Hallgrimsson
J
J
Katoh
R
R
Ng
O L
OL
Satir
A
A
Williams
G T
GT
Williams
E D
ED
D000107:Acetylation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000378:metabolism*; D005260:Female; D005787:Gene Frequency; D006579:Heterozygote; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010503:Periodic Acid-Schiff Reaction; D010641:Phenotype; D011110:Polymorphism, Genetic; D044469:Racial Groups; D012795:Sialoglycoproteins / Q000235:genetics / Q000378:metabolism*
D012795:Sialoglycoproteins