title: Juvenile idiopathic polyarticular arthritis and IgA deficiency in the 22q11 deletion syndrome.
abstract: Five patients with the 22q11 deletion syndrome (velocardiofacial syndrome) developed chronic inflammatory polyarticular arthritis. These new cases add to 8 previously reported and confirm the association. The arthritis in all cases was moderate to severe, but at least partially responsive to methotrexate and/or corticosteroids, and was clinically indistinguishable from juvenile idiopathic arthritis (JIA). Analysis of the total 13 patients indicates that 2 are rheumatoid factor positive, 6 are antinuclear antibody positive, 5 have subtle T cell deficiencies, and 6 have hypergammaglobulinemia. Of particular interest is the occurrence of IgA deficiency in 4 patients, including 2 from our own series. Although IgA deficiency is seen in both JIA (2-4%) and 22q11 deletion syndrome (2-4%), the prevalence of low IgA in this series (31%) is much greater than expected. This phenomenon and the true association of inflammatory arthritis and a chromosome deletion disorder provides further evidence of important genetic factors in the pathogenesis of JIA.
authors.affiliation: Department of Rheumatology, Great Ormond Street Hospital for Sick Children, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Davies
authors.forename: E R
authors.initials: ER
authors.lastname: Stiehm
authors.forename: P
authors.initials: P
authors.lastname: Woo
authors.forename: K J
authors.initials: KJ
authors.lastname: Murray
mesh_terms: D000293:Adolescent; D000328:Adult; D001171:Arthritis, Juvenile / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D002675:Child, Preschool; D002892:Chromosomes, Human, Pair 22; D004062:DiGeorge Syndrome / Q000453:epidemiology / Q000235:genetics / Q000276:immunology; D005260:Female; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D017098:IgA Deficiency / Q000453:epidemiology / Q000235:genetics*; D008297:Male; D015995:Prevalence