Familial lupus in Tunisia: a series of 14 families.

The relatively high prevalence of systemic lupus erythematosus (SLE) in familial cases supports genetic susceptibility to this disease. Although many advances have been made in the identification of new genes implicated in lupus pathogenesis, to date, there has been no large study of familial SLE. We report what we believe to be the first study of familial SLE in the North African population. The objectives of this study were to determine the main clinical and laboratory features of familial lupus and to compare them to sporadic lupus in a population of Tunisian patients. Fourteen families in which the diagnosis of lupus could be verified in at least two relatives were included in the study. All patients fulfilled four or more criteria defined by the American College of Rheumatology. Twenty-seven patients (23 females and 4 males) with familial SLE among a cohort of 253 SLE patients were found, resulting in a frequency of 10.67%. No significant differences were found between familial SLE cases and their controls in terms of sex ratio, mean age at onset and clinical and serological manifestations, which is consistent with the results of other series reported in the literature. Our results support the importance of carrying out more genetic studies within families of SLE in order to have a better understanding of the genetic and molecular mechanisms of the disease.