 Most coeliacs inherit only one copy of this DQ2.5 haplotype, while some inherit it from "both" parents; the latter are especially at risk for coeliac disease as well as being more susceptible to severe complications.Some individuals inherit DQ2.5 from one parent and an additional portion of the haplotype (either DQB1*02 or DQA1*05) from the other parent, increasing risk.Less commonly, some individuals inherit the DQA1*05 allele from one parent and the DQB1*02 from the other parent (DQ2.5trans) (called a trans-haplotype association), and these individuals are at similar risk for coeliac disease as those with a single DQ2.5-bearing chromosome 6, but in this instance disease tends not to be familial.