HLA DQA1 and DQB1 study in Algerian type 1 diabetes families.
The distribution of HLA class II alleles associated with insulin-dependent diabetes mellitus (Type 1) in the Algerian population is poorly known. We have typed 36 Algerian Type 1 diabetic probands and their families using DQA1 and DQB1 oligonucleotide probes. Fifty-nine parental haplotypes non transmitted to diabetic offspring served as controls. The frequencies of DQA1 and DQB1 alleles and haplotypes and their associations with Type 1 diabetes were, except minor differences, similar to those reported in French. Susceptibility DQA1 (Arg52+) and DQB1 (Asp57-) alleles were significantly increased among patients versus controls (90% vs 53%, RR = 8.4, p < 10(-6), and 94% vs 64%, RR = 9.4, p < 10(-5), respectively). 85% of Type 1 diabetics versus 34% of control haplotypes were either DR3DQw2 or DR4DQw8 susceptibility haplotypes (DQA1 Arg52+, DQB1 Asp57-) (RR = 10.8, p < 10(-7). 75% of the probands vs 14% of the controls (RR = 18, p < 10(-5)) and 73% of affected siblings versus 24% of unaffected siblings (RR = 8.4, p < 0.02) possessed a genotype composed of these two susceptibility haplotypes in the homozygous or heterozygous state. 42% of the probands were DR3DQw2/DR4DQw8, corresponding to Hardy-Weinberg expectations. The lack of excess of heterozygotes could be due to the consanguine families in this sample, as among the patients with consanguine parents the frequency of DR3, 4 heterozygotes was lower (27% vs 48% in non-consanguine patients, NS) and that of DR3 homozygotes increased (45% vs 12%, respectively, p < 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)
Beressi
J P
JP
INSERM U30, Hôpital Necker, Paris, France.
Djoulah
S
S
Khalil
I
I
Benhamamouch
S
S
Bessaoud
K
K
Touhami
M
M
Hors
J
J
Deschamps
I
I
D000462:Algeria; D003241:Consanguinity; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000276:immunology*; D005260:Female; D005602:France; D005838:Genotype; D006683:HLA-DQ Antigens / Q000032:analysis* / Q000097:blood / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006239:Haplotypes; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D015345:Oligonucleotide Probes
D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D015345:Oligonucleotide Probes