Tap gene associations in UK caucasoids.
The authors determined the allele frequencies of the TAP1 and TAP2 transporter genes in a healthy UK Caucasoid population by ARMS-PCR. TAP1A was the most frequent TAP1 allele by far, being present in 76% of subjects. TAP1 alleles could not be assigned in 24% of subjects, since the combinations TAP1A/1b and TAP1C/1D cannot be separated. TAP2A was the most frequent TAP2 alleles (75% of subjects) followed by TAP2B (43%), TAP2C (11%), TAP2D (8%) and TAP2E (6%). The authors also identified an individual with a previously undescribed TAP2 allele, TAP2H (isoleucine at amino acid [aa] 379, alanine at aa 565, alanine at aa 665). It was not possible to assign unequivocally TAP2 alleles in 15 individuals (9%) as TAP2A/D and TAP2C/E cannot be distinguished from each other. To address this problem a separate study of families of rheumatoid arthritis (RA) patients selected for this ambiguity were studied. In all five informative families, TAP2A/2D was confirmed as the combination present. In the population studied no evidence was found for linkage disequilibrium between TAP1 and TAP2 or between the TAP genes and HLA-DP. There was no evidence for extensive linkage disequilibrium between the TAP genes and HLA-DQR, although TAP2B was associated with DRI (delta = 0.056, corrected P < 0.01) and TAP2D with DR4 (delta = 0.018). In the RA families studied, TAP2D was found on DRB1*0401-bearing haplotypes.
Donn
R P
RP
ARC Epidemiology Research Unit, University of Manchester, UK.
Davies
E J
EJ
Thomson
W
W
Hillarby
M C
MC
Ollier
W E
WE
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000483:Alleles; D005260:Female; D005787:Gene Frequency; D006801:Humans; D015810:Linkage Disequilibrium; D008285:Major Histocompatibility Complex; D008297:Male; D010375:Pedigree; D006113:United Kingdom; D044465:White People / Q000235:genetics*
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; C073119:TAP1 protein, human; C071692:TAP2 protein, human