A systematic study of HLA class II-beta DNA restriction fragments in insulin-dependent diabetes mellitus.
DNA restriction fragments of the genes encoding HLA class II-beta antigens were compared in 34 patients with insulin-dependent diabetes mellitus and 34 HLA-DR-matched healthy individuals. Ninety-three fragments, determined by six restriction enzymes (EcoRI, EcoRV, HindIII, BamHI, Pvu II, and Taq I), were analyzed: (i) A DR Taq I 12.7-kilobase-pair fragment might be a marker for the extended haplotype HLA-B8, DR3. (ii) In controls, DR4 haplotypes are associated with two distinct clusters of DQ restriction fragments (DQR4 and DQR5). Almost all (94%) DR4 patients belong to the DQR4 and not to the DQR5 cluster. This suggests that, among HLA-DR4 haplotypes, only DQR4 haplotypes are involved in susceptibility to insulin-dependent diabetes mellitus. (iii) A DR Taq I 14.5-kilobase-pair fragment was found to be strongly associated with DQR4, mainly in DR3/DR4 heterozygous patients (P = 5 X 10(-4). However, these results must be interpreted with caution, taking into account the high number of statistical tests performed.
Cohen-Haguenauer
O
O
Robbins
E
E
Massart
C
C
Busson
M
M
Deschamps
I
I
Hors
J
J
Lalouel
J M
JM
Dausset
J
J
Cohen
D
D
D004262:DNA Restriction Enzymes; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000276:immunology; D005796:Genes; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D011110:Polymorphism, Genetic; D013223:Statistics as Topic
D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D004262:DNA Restriction Enzymes