Normal RNAi response in human fragile × fibroblasts

BACKGROUND: Fragile × syndrome is caused by loss of expression of the FMRP protein involved in the control of a large number of mRNA targets. The Drosophila ortholog dFXR interacts with a protein complex that includes Argonaute2, an essential component of the RNA-induced silencing complex (RISC). Furthermore dFXR associates with Dicer, another essential processing enzyme of the RNAi pathway. Both microRNA and microRNA precursors can co-immunoprecipitate with dFXR. Consequently it has been suggested that the Fragile × syndrome may be due to a defect in an RNAi-related apparatus. FINDINGS: We have investigated the RNAi response in Fragile × patient cells lacking FMRP compared with normal controls. RNAi responses were successfully detected, but no statistically significant difference between the response in normal cells compared to patients cells was found - neither one nor two days after transfection. CONCLUSION: Our data show that in human fibroblasts from Fragile × patients lacking FMRP the RNAi response is not significantly impaired.