PRPH and amyotrophic lateral sclerosis: PRPH acts as a cytoskeletal protein, is present in the neurons of the peripheral nervous system and helps in axonal regeneration [117]. Overexpression of wild-type PRPH in transgenic mice develops a selective, large scale late-onset motor neuron degeneration characterized by intermediate filament inclusions [118]. Two homozygous missense mutations have been identified in PRPH gene which may contribute to the ALS pathogenesis [119].