Heterogeneity of the human H blood group alpha(1,2)fucosyltransferase gene among para-Bombay individuals.
OBJECTIVE
The para-Bombay phenotype has a relatively high frequency of about 1 in 8,000 Taiwanese. Studies were carried out on eight healthy and unrelated Taiwanese with the para-Bombay phenotype to cast light on its immunogenetic basis.


METHODS
Blood and saliva samples were tested with standard hemagglutination techniques. Salivary ABH substances were determined by hemagglutination inhibition. PCR techniques were used to amplify the coding region of the H genes.


RESULTS
Five different h alleles, designated as h1, h2, h3, h4 and h5, were identified in the Taiwanese with the para-Bombay phenotype. The h1 allele loses one of the three AG repeats located at the nucleotides 547-552 of the H gene, whereas two of the three T repeats located at the nucleotides 880-882 are deleted in the h2 allele. The h3 allele contains a C658 to T missense mutation, whereas two missense mutations, C35 to T and A980 to C were identified in the h4 allele. A T460 to C missense is present in the h5 allele. The h5 allele was identified in an individual whose red blood cells contain blood group A antigen but not H antigen, and thus may be considered a weak variant of the H gene.


CONCLUSIONS
So far no biologic relevance of the H antigen has been discovered, and its deficiency does not seem to produce any deleterious effects. There may be better understanding of the evolutionary basis for the polymorphisms at these loci after systematic study of different ethnic populations.
Yu
L C
LC
Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan, ROC.
Yang
Y H
YH
Broadberry
R E
RE
Chen
Y H
YH
Lin
M
M
D000017:ABO Blood-Group System / Q000235:genetics*; D000483:Alleles; D005647:Fucosyltransferases / Q000235:genetics*; D006801:Humans; D009154:Mutation; D011110:Polymorphism, Genetic; D000097631:Galactoside 2-alpha-L-fucosyltransferase
D000017:ABO Blood-Group System; D005647:Fucosyltransferases; D000097631:Galactoside 2-alpha-L-fucosyltransferase