FMR1 and proximal spinal muscular atrophy: Several ribosome-associated proteins (RAPs) implicated in human disease interact directly with ribosomes, including Fragile X mental retardation protein (FMRP), which represses translation of a specific group of mRNAs [53], and survival motor neuron protein (SMN) which regulates translation of transcripts implicated in the pathogenesis of Spinal Muscular Atrophy (SMA) [54].