Polymorphism and distribution of HLA-DR2 alleles and haplotypes in a Greek population.
HLA-DR2 serological subtyping has indicated that the DR16 serotype appears at a higher frequency relative to the DR15 serotype in the Greek population, differing from the distribution observed in most other Caucasian groups. In this study, we have analyzed by the PCR-SSP technique a DR2-positive group of unrelated Greek individuals selected from our normal control panel for the different DRB1, DRB5, DQB1 and DQA1 DR2-associated alleles present. Six of the 50 individuals analyzed were homozygous for DR2, contributing a total of 56 haplotypes for DR2. The observed frequencies of the DR2-related DRB1 alleles were as follows: 58.9% for the DRB1*1601, 7.1% for the DRB1*1602, 25.0% for the DRB1*1501 and 7.1 % for the DRB1*1502 allele. The rare allele DRB1*1605 was detected in one heterozygous sample and its presence was definitively established by DNA sequencing. The alleles *1503, *1504, *1505, *1603 and *1604 were not detected. Three DRB5 alleles were identified: DRB5*0202 (67.8%), DRB5*0101 (25.0%) and DRB5*0102 (7.1%). Ten different DRB1/DQB1/ DQA1 DR2-associated haplotypes were defined. The most frequently observed haplotype was DRB1*1601-DQB1*0502-DQA1*0102 (relative frequency=57%) followed by DRB1*1501-DQB1*0602-DQA1*0102 (relative frequency=14.3%). In conclusion, the refined analysis of the DR2-associated DRB1 alleles in the Greek population revealed the prevalence of the DRB1*1601 allele. The rare allele DRB1*1605 was demonstrated once. A considerable variety of different DR2-related DR/DQ haplotypes was detected and the overall haplotypic frequencies in the Greek population are distributed differently compared to those reported for most other Caucasian populations.
Constantinidou
N
N
Aghia Sophia Children's Hospital, Department of Immunology-Histocompatibility, Athens, Greece.
Chaidaroglou
A
A
Van den Berg-Loonen
E M
EM
Koniavitou
K
K
D000483:Alleles; D006115:Greece; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D015802:HLA-DR2 Antigen / Q000235:genetics*; D059811:HLA-DRB1 Chains; D059847:HLA-DRB5 Chains; D006239:Haplotypes; D006801:Humans; D011110:Polymorphism, Genetic
D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; C069050:HLA-DQA1 antigen; D006684:HLA-DR Antigens; D015802:HLA-DR2 Antigen; D059811:HLA-DRB1 Chains; D059847:HLA-DRB5 Chains