Comparison of TAP2 frequencies in type 1 diabetes patients and healthy controls from three ethnic groups indicates an African origin for the TAP2 G allele.
In order to determine the ethnic origin of the transporter associated with antigen processing 2 (TAP2) G allele, initially discovered by us in a group of type 1 diabetes (insulin-dependent diabetes mellitus) patients living on Reunion Island, HLA TAP2 typing was performed using the polymerase chain reaction-amplification refractory mutation system (PCR-ARMS) method in type 1 diabetes patients and unrelated healthy controls of three different ethnic groups (Caucasians, Indians and black Africans from Senegal and Mauritius). The comparison of TAP2 allele frequencies in controls showed significant racial (ethnic) differences. The TAP2*0101 and TAP2 C alleles were increased, respectively, in the Caucasian (50% in Caucasians vs. 40% in other groups) and Senegalese (27% in Senegalese vs. 10% in other groups) populations. In comparison with Caucasians, the TAP2*0201 variant was significantly increased in the Indian population and decreased in the Senegalese black population. In addition, the TAP2 G allele was observed in the two African populations studied but not in the Caucasian or Indian population. This observation is consistent with the view that this allele is restricted to populations of African origin. In addition, we have determined the large extended haplotype DQA1-DQB1-DRB1 associated with TAP2 G. We found that this allele is preferentially associated with the large conserved haplotype HLA DQA1*0501-DQB1*0201-DRB1*0301.
Hoarau
J J
JJ
Universite de la Reunion, Secretariat du Laboratoire de Biochimie et Genetique Moleculaire, 15 Avenue Rene Cassin, 97715 Saint Denis Messag, Cedex 9, La Reunion, France.
Cesari
M
M
Dieye
A
A
Kotea
N
N
Surrun
S K
SK
Moine
A
A
Caillens
H
H
Cadet
F
F
Pabion
M
M
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000483:Alleles; D044383:Black People / Q000235:genetics*; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005006:Ethnicity; D005787:Gene Frequency; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007194:India; D015810:Linkage Disequilibrium; D017508:Reunion / Q000208:ethnology; D044465:White People / Q000235:genetics
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C553502:HLA-DRB1*03:01 antigen; C071692:TAP2 protein, human