The role of major histocompatibility complex alleles in the susceptibility of Brazilian patients to develop the myogenic type of Graves' orbitopathy

Thyroid. 2008 Apr;18(4):443-7. doi: 10.1089/thy.2007.0194.


Objective: To assess the frequency of the genetic markers HLA-DRB1 and DQB1 in patients with Graves' orbitopathy (GO) with and without extraocular muscle involvement.

Design: The frequencies of class II HLA-DRB1 and DQB1 allele groups were determined for 81 Brazilian patients with GO and 161 normal subjects. The patients were divided into myogenic and nonmyogenic groups based on the clinical characteristics of the orbitopathy and quantitative computed tomography analysis of the extraocular muscle (EOM) dimensions.

Main outcome: Compared to the frequency obtained for samples of normal subjects of the Brazilian population, HLA-DRB1 16 ( pc=0.008) was overrepresented in myogenic and HLA-DRB1 03 ( pc=0.02) in nonmyogenic patients.

Conclusions: The association between the HLA-DRB1 16 and the myogenic subtype of GO suggests that EOM involvement in GO may be genetically predisposed.

MeSH terms

  • Adult
  • Alleles*
  • Brazil
  • Case-Control Studies
  • Female
  • Gene Frequency
  • Genetic Predisposition to Disease*
  • Graves Disease / diagnosis*
  • Graves Disease / genetics*
  • Graves Disease / immunology
  • HLA-DQ Antigens / genetics*
  • HLA-DQ beta-Chains
  • HLA-DR Antigens / genetics*
  • HLA-DRB1 Chains
  • Humans
  • Major Histocompatibility Complex / genetics*
  • Male
  • Middle Aged
  • Muscular Diseases / complications
  • Muscular Diseases / genetics


  • HLA-DQ Antigens
  • HLA-DQ beta-Chains
  • HLA-DQB1 antigen
  • HLA-DR Antigens
  • HLA-DRB1 Chains