HLA associated type 1 diabetes risk in children of Pakistani migrants to Norway

Area of Science:

• Immunogenetics
• Endocrinology
• Population Genetics

Background:

• Type 1 diabetes (T1D) arises from complex gene-environment interactions.
• Understanding genetic predisposition, particularly Human Leukocyte Antigen (HLA) associations, is crucial for T1D risk assessment.

Purpose of the Study:

• To investigate HLA-associated T1D risk in Pakistani newborns residing in Norway.
• To analyze HLA-DRB1, -DQB1, and -DQA1 alleles and haplotypes in this specific migrant population.

Main Methods:

• High-resolution HLA genotyping of DNA samples from 189 newborns with Pakistani first-generation migrant parents.
• Analysis of DRB1, DQB1, and DQA1 loci to identify specific alleles and haplotypes.

Main Results:

• Identified 28 DRB1, 13 DQB1, and 9 DQA1 alleles, forming 39 distinct haplotypes.
• The DR3-DQ2 haplotype, a known T1D susceptibility factor, was found in 18.5% of newborns, with 18.6% being homozygotes.
• A wide spectrum of HLA haplotypes was observed, with only a minority linked to T1D susceptibility.

Conclusions:

• The study identified a diverse range of HLA haplotypes in Norwegian newborns of Pakistani descent.
• The low incidence of T1D in South/East Asian immigrants in Norway, coupled with the observed HLA diversity, suggests environmental factors are more likely triggers than genetic susceptibility.
• Future increases in T1D incidence in this population may indicate the role of environmental triggers, mirroring trends observed elsewhere.