Familial aggregation and linkage analysis of autoantibody traits in pedigrees multiplex for systemic lupus erythematosus

• Published in: Genes and immunity Vol. 7; no. 5; pp. 417 - 432
• Main Authors: Ramos, P S, Kelly, J A, Gray-McGuire, C, Bruner, G R, Leiran, A N, Meyer, C M, Namjou, B, Espe, K J, Ortmann, W A, Reichlin, M, Langefeld, C D, James, J A, Gaffney, P M, Behrens, T W, Harley, J B, Moser, K L
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01-07-2006
• Subjects: African Americans; Antibodies, Antinuclear - blood; Antinuclear antibodies; Antiphospholipid antibodies; Autoantibodies; Autoantibodies - blood; Autoantibodies - classification; Autoantibodies - genetics; Autoimmune diseases; Autoimmune Diseases - genetics; Biomarkers - blood; Case-Control Studies; Chromosome 13; Chromosome 3; Chromosome 4; Chromosome Mapping; Chromosomes; Chromosomes, Human, Pair 13; Chromosomes, Human, Pair 3; Chromosomes, Human, Pair 4; Diagnosis; European Continental Ancestry Group; Female; Genetic aspects; Genetic Linkage; Genetic Predisposition to Disease; Genomes; Health aspects; Humans; Immunoglobulin M; Linkage (Genetics); Linkage analysis; Lupus; Lupus Erythematosus, Systemic - genetics; Lupus Erythematosus, Systemic - immunology; Male; Molecular modelling; Pedigree; Phospholipids; Physiological aspects; Rheumatoid factor; Ro(SSA) antigen; Systemic lupus erythematosus; United States
• ISSN: 1466-4879; 1476-5470
• DOI: 10.1038/sj.gene.6364316

Autoantibodies are clinically relevant biomarkers for numerous autoimmune disorders. The genetic basis of autoantibody production in systemic lupus erythematosus (SLE) and other autoimmune diseases is poorly understood. In this study, we characterized autoantibody profiles in 1,506 individuals from 229 multiplex SLE pedigrees. There was strong familial aggregation of antinuclear antibodies (ANAs), anti-double-stranded DNA (dsDNA), anti-La/SSB, anti-Ro/SSA, anti-Sm, anti-nRNP (nuclear ribonucleoprotein), IgM antiphospholipid (aPL) antibodies (Abs) and rheumatoid factor (RF) across these families enriched for lupus. We performed genome-wide linkage analyses in an effort to map genes that contribute to the production of the following autoantibodies: Ro/SSA, La/SSB, nRNP, Sm, dsDNA, RF, nuclear and phospholipids. Using an approach to minimize false positives and adjust for multiple comparisons, evidence for linkage was found to anti-La/SSB Abs on chromosome 3q21 (adjusted P=1.9 x 10(-6)), to anti-nRNP and/or anti-Sm Abs on chromosome 3q27 (adjusted P=3.5 x 10(-6)), to anti-Ro/SSA and/or anti-La/SSB Abs on chromosome 4q34-q35 (adjusted P=3.4 x 10(-4)) and to anti-IgM aPL Abs on chromosome 13q14 (adjusted P=2.3 x 10(-4)). These results support the hypothesis that autoantibody production is a genetically complex trait. Identification of the causative alleles will advance our understanding of critical molecular mechanisms that underlie SLE and perhaps other autoimmune diseases.