FAMILY HISTORY AS A RISK FACTOR FOR RHEUMATOID-ARTHRITIS - A CASE-CONTROL STUDY

Objective, To investigate the risk of rheumatoid arthritis (RA) in fir st degree relatives and to investigate whether the sex of the parent i nfluences the pattern of inheritance. Methods. An interview based case -control study, with subjects serially matched for age and sex. We ana lyzed 126 cases (hospital cases) and 94 controls (derived from the sam e hospitals), who gave information for family history of RA. Data conc erning RA history among siblings and parents were computerized and ana lyzed univariately and multivariately, Results. The odds ratio (OR) fo r developing RA is 4.4 (p < 0.001) if a first degree relative reported having the disease and 5.4 (p < 0.01) if a female first degree relati ve reported having the disease, For females the OR is 7.0 (p < 0.01) i f the first degree relative is female. When the analysis was restricte d to parents only, it was found that mothers with RA predispose their daughters and sons to develop RA more (OR = 8.6, p < 0.01, for daughte rs and 4.8, p < 0.05, for both sexes) than fathers (OR = 1.1 and 1.9, respectively). Conclusion, This case-control study confirms the famili al clustering of RA and suggests that mothers confer susceptibility to RA on their offspring more often than fathers.