Carriers of the TCF7L2 gene variant have a milder immunological and metabolic phenotype at type 1 diabetes diagnosis, which appears to be caused in part by type 2 diabetes-like pathogenic mechanisms, researchers concluded after conducting a study involving 810 individuals. Participants—who ranged in age between 3 and 59 years and were a median age of 14—had newly diagnosed autoimmune type 1 diabetes and TCF7L2 rs4506565 and rs7901695 single-nucleotide polymorphism (SNP) data available. Investigators looked at how the variant impacted the number of islet autoantibodies and C-peptide and glucose measures at diagnosis. Among the results:

• Those with the rs4506565 variant were 66% more likely to express a single autoantibody, rather than multiple autoantibodies, at diagnosis.
• This link was significant only in those aged ≥12 years.
• The rs4506565 variant was independently linked with higher C-peptide area under the curve (AUC) and lower average glucose AUC.
• The same was true for the rs7901695 variant.