Diabetes Care, Vol 17, Issue 2 132-137, Copyright © 1994 by American Diabetes Association
Ethnic differences in human leukocyte antigen markers of susceptibility to IDDM
KJ Cruickshanks, LF Jobim, J Lawler-Heavner, TG Neville, EC Gay, HP Chase, G Klingensmith, JA Todd and RF Hamman
Department of Preventive Medicine and Biometrics, University of Colorado School of Medicine, Denver.
OBJECTIVE--To determine whether genetic differences explain the lower risk
of developing insulin-dependent diabetes mellitus (IDDM) for Hispanic
versus non-Hispanic white children in Colorado. RESEARCH DESIGN AND
METHODS--Hispanic (n = 62) and non-Hispanic white (n = 82) subjects with
IDDM identified from the Colorado IDDM Registry and healthy, nondiabetic
control subjects were recruited. Human leukocyte antigen (HLA) serologic
typing and sequence-specific oligonucleotide typing of DQA1 and DQB1
alleles were performed. RESULTS--HLA and allele associations with IDDM were
similar in both ethnic groups. HLA-DR3 and HLA-DR4 were more common in IDDM
subjects in both ethnic groups. Subjects with DQBl alleles encoding
aspartic acid (Asp) in position 57 were less likely to have IDDM,
irrespective of ethnic background. HLA-DR3 was less common among Hispanic
subjects than non-Hispanic white control subjects (4.4 vs. 17.5%, Hispanics
vs. non-Hispanic whites, P = 0.04). CONCLUSIONS--These data suggest that
the lower prevalence of HLA-DR3 in the Hispanic population, a pattern
consistent with the presence of Amerindian admixture, may explain the lower
rate of IDDM in the Hispanic population.