Sequencing of the second exon of the MHC class II DQ6 alleles in patients with type 1 diabetes

Autoimmunity. 2002 Mar;35(2):155-7. doi: 10.1080/08916930290016637.


The MHC class II molecule DQ6 is strongly associated with protection from type 1 diabetes. A small number of diabetic subjects have been typed as positive for DQ6, but it has been suggested that these individuals may possess a mutant form of the molecule, which is structurally altered in such a way as to abrogate its protective effect. In order to test this hypothesis, eight diabetic individuals positive for DQ6 were investigated. The second exons of the alleles encoding DQ6, DQA1*0102 and DQB1*0602, were sequenced using fluorescently labelled dideoxynucleotides. No mutations were found. This suggests that all the subjects possessed the "wild-type" second exons of the DQ6 alleles and, hence, that the protective effect associated with the antigen-binding domain of DQ6 is not absolute.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alleles*
  • Child
  • Diabetes Mellitus, Type 1 / genetics*
  • Exons / genetics*
  • HLA-DQ Antigens / chemistry
  • HLA-DQ Antigens / genetics*
  • Humans
  • Sequence Analysis, DNA


  • HLA-DQ Antigens
  • HLA-DQ6 antigen