Celiac Disease Genes Mapped in Southern Brazil

Scientists studied the genetics behind celiac disease in southern Brazil. They looked at 171 people with the condition and 195 healthy controls. The team sequenced HLA genes at high resolution and checked 16 other genetic markers linked to celiac in earlier studies. Controls had no diagnosis, no affected family members, and tested negative for anti-TTG antibodies.

Most patients carried two key HLA combinations. The first, called DQ2.5, showed up in 51.7% of cases. The second, DQ2.2, appeared in 40.2%. These are the same genetic signatures often tied to celiac disease worldwide.

One ancestral group of HLA genes, known as the 8.1 haplotype, raised the odds of getting celiac by 6.5 times. Other HLA types like DQA101:02:01 and DRB113:01:01 were more common in healthy people, suggesting they may offer some protection.

Unlike studies in mostly European groups, the DQ8 variant did not differ much between patients and controls. This hints that genetic risk can vary across populations.

Outside the main HLA region, two non-HLA genes stood out. A variant in NFIA seemed to lower risk, while a change in ATXN2 increased it. This is the first detailed HLA study of celiac disease in Brazil and reveals new genetic clues in an admixed population.