Association between IgH enhancer hs1.2 and type 1 diabetes

Area of Science:

• Immunogenetics
• Autoimmune diseases

Background:

• Type 1 diabetes (T1D) is an autoimmune disease with complex genetic underpinnings.
• Genetic variations in immune regulatory regions are implicated in autoimmune susceptibility.

Purpose of the Study:

• To investigate the association between alleles of the 3' immunoglobulin heavy-chain regulatory region 1 (3'RR-1) enhancer hs1.2 and T1D.
• To explore if this association is modified by the presence of coeliac disease (CD) or autoimmune thyroid disease (AITD).

Main Methods:

• A case-control study comparing 81 T1D patients (including those with CD or AITD) and 248 healthy controls.
• Genotyping of the hs1.2 enhancer alleles using nested PCR amplification of the 3'RR-1 core region.

Main Results:

• Significant differences in hs1.2 allele distribution were observed between T1D patients and healthy controls (p < 0.01).
• Allele distribution showed even greater differences in T1D patients with concomitant CD compared to T1D patients without CD.
• The frequency of the *2 allele was notably increased by 23% in T1D patients with coexisting CD.

Conclusions:

• The multiallelic hs1.2 enhancer of the 3'RR-1 is associated with T1D.
• This association is particularly pronounced in patients with co-occurring CD, suggesting a shared genetic susceptibility.
• These findings align with previous observations linking this genetic region to other immune-mediated diseases.