A Locus on Chromosome 9p Predisposes to a Specific Disease Manifestation, Acute Anterior Uveitis, in Ankylosing Spondylitis, a Genetically Complex, Multisystem, Inflammatory Disease

Arthritis Rheum. 2005 Jan;52(1):269-74. doi: 10.1002/art.20777.

Abstract

Objective: Uveitis or intraocular inflammation is a major cause of visual loss. Acute anterior uveitis (AAU) affects approximately 40% of patients with ankylosing spondylitis (AS) but also affects patients with no evidence of spondylarthritis. We sought to determine whether a unique genetic region could be implicated in a specific manifestation-AAU-of a multisystem, inflammatory, genetically complex disease, AS.

Methods: Individuals from families multiplex for AAU were genotyped at 400 markers representing the ABI PRISM linkage map MD-10, and at the HLA-B, DRB1, DQA1, DQB1, and DPB1 alleles. Among the family members with AAU, 76 affected sibpairs were analyzed (6 without concomitant AS, 12 discordant for AS, and 58 concordant for AS). Two-point and multipoint nonparametric linkage analyses were performed, and 1-parameter allele-sharing model logarithm of odds (LOD) scores were determined.

Results: As previously reported for AS, linkage at the major histocompatibility complex region (chromosome 6p21) was evident, exhibiting the highest multipoint LOD score (4.96 at marker HLA-B). Strong linkage was seen at a region on chromosome 9p21-9p24, with a LOD score of 3.72 at marker D9S157. When compared with a companion cohort of AS families, the linkage at this region was found in association with AAU but not with AS. A third region on chromosome 1q23-1q31 was observed to have suggestive linkage (LOD 2.05 at marker D1S238), which overlaps with a region associated with AS.

Conclusion: This is the first study in which a genetic region for AAU has been identified by genome-wide scan. Even though AS was highly prevalent in this cohort of families, a locus at chromosome 9p21-9p24 was identified that uniquely associates with AAU. Identifying the genetic perturbation at this region may advance our understanding of the mechanisms involved in tissue-specific pathology of complex inflammatory diseases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acute Disease
  • Chromosome Mapping*
  • Chromosomes, Human, Pair 1
  • Chromosomes, Human, Pair 6
  • Chromosomes, Human, Pair 9*
  • Genetic Linkage
  • Genetic Predisposition to Disease*
  • HLA-B Antigens / genetics
  • Humans
  • Lod Score
  • Major Histocompatibility Complex / genetics
  • Spondylitis, Ankylosing / genetics*
  • Uveitis, Anterior / genetics*

Substances

  • HLA-B Antigens