Objective: TNFRSF1A mutations cause TRAPS (MIM#142680). A recent study suggested that the R92Q mutation was associated with polyarthritis. We aimed at searching for this and other TNFRSF1A mutations in RA, to be tested for linkage.
Material and methods: the 386 DNA of 100 trio families and 86 index cases of RA affected sib-pair (ASP) families from the French Caucasian population were investigated by dHPLC (denatured high-performance liquid chromatography) for TNFRSF1A mutations in exons 2 to 4. The test for association compared cases and controls (derived from un-transmitted parental chromosomes). The test for linkage relied on the transmission disequilibrium test (TDT) in trio families and cosegregation in ASP families.
Results: Only the R92Q mutation was detected, in 2 of the 100 index cases of trio families and 5 (5.8%) of the index cases of ASP families, but also 5% of the controls, showing no association with the disease. No RA linkage evidence was found in TDT and ASP RA families.
Conclusion: This TNFRSF1A investigation in RA from the French Caucasian population showed only the R92Q mutation, with a frequency of 4.5%, but no evidence for RA association nor linkage to the disease. The R92Q mutation could be considered as a low-penetrance variant.
- rheumatoid arthritis