Activating Signal Cointegrator 1 complex (ASC-1 complex) is a ribonucleoprotein tetramer participating in transcriptional coactivation and RNA processing, consisting of four subunits: ASCC1-ASCC3 and ASC-1. Pathogenic variants in the TRIP4 and ASCC1 genes, encoding the ASC-1 and ASCC1 subunits, were recently described in congenital myopathic conditions without signs of motor neuron involvement, and Spinal Muscular Atrophy-like (SMA-like) phenotype with prenatal bone fractures. We present a novel pathogenic TRIP4 variant in two siblings with severe phenotype and mixed sensory-motor polyneuropathy. The reviewed phenotypic spectrum is broad, but sensory-motor polyneuropathy is so-far unreported. We thus expand ASC-1 related myopathy phenotype.
Keywords: ASC-1; TRIP4; hypotonia; myopathy; neuropathy.