O.3 Satellite cell loss is the pathomechanism leading to muscle atrophy in selenoprotein N deficiency

Abstract

zygous for the RT insertion mutation, five of whom carried a novel intronic mutation that activates a pseudoexon between exons 5 and 6 (c.647 + 2084G > T). Compared with individuals that were homozygous for the RT insertion mutation, the seven heterozygotes for the RT insertion mutation, including five patients with the novel pseudoexon mutation, exhibited a more severe clinical phenotype in terms of motor abilities and more extensive brain MRI abnormalities (i.e., a wider distribution of cortical malformation, pons and cerebellar hypoplasia, and more frequent diffuse white matter changes and ventricular dilatation). Conclusions FKTN mutations are the most common genetic cause of CMD with defective a-DG glycosylation in Korea. Compound heterozygosity of the RT insertion and the novel pseudoexon mutation is the most prevalent genotype in Korea and is associated with a more severe clinical phenotype and a wider extent of brain MRI abnormalities compared with homozygosity for the RT insertion mutation.