EVALUATION OF THE BCL-2 GENE LOCUS AS A SUSCEPTIBILITY LOCUS LINKED TO THE CLINICAL EXPRESSION OF SYSTEMIC LUPUS-ERYTHEMATOSUS (SLE)

Systemic lupus erythematosus (SLE) is an autoimmune disease characteri sed by the production of a large number of autoantibodies. It has been postulated that this may be the result of prolonged longevity of auto -reactive B cells due to defective regulation of programmed cell death (apoptosis). The proto-oncogene bcl-2 is involved in the control of a poptosis in immunocompetent cells, and its over-expression is noted in T and B cells from SLE patients. This study examined the genetic link age between the bcl-2 gene locus and SLE susceptibility using the affe cted sib-pair method in SLE families. Seventeen caucasian multiplex fa milies were evaluated. A polymorphic microsatellite marker closely lin ked to the bcl-2 gene on 18q21.3 was used to determine the bcl-2 genot ype. We demonstrated that haplotype sharing among the affected sibling pairs was not statistically different from random (P>0.5). This sugge sts that the bcl-2 gene locus does not confer agenetic susceptibility to SLE expression.