A TRAPPC6B splicing variant associates to restless legs syndrome

Introduction RLS is a common movement disorders with a strong genetic component in its pathophysiology, but, up to now, no causative mutation has been reported. Methods We re-evaluated the previously described RLS2 family by exome sequencing. Results We identified fifteen variations in the 14q critical region. The c.485G > A transition of the TRAPPC6B gene segregates with the RLS2 haplotype, is absent in 200 local controls and is extremely rare in 12988 exomes from the Exome Variant Server (EVS). This variant alters a splicing site and hampers the normal transcript processing by promoting exon 3-skipping as demonstrated by minigene transfection and by patient transcripts. Conclusions We identified a TRAPPC6B gene mutation associated to the RLS locus on chromosome 14.