PRX (periaxin) is a scaffolding protein essential for peripheral nerve function and myelin maintenance. It operates as part of the dystroglycan complex in Schwann cells and coordinates with EZR and AHNAK-containing complexes in lens fiber cells. PRX is required for normal myelin sheath organization, including formation of Cajal bands and Schmidt-Lanterman incisures, and facilitates transport of myelin basic protein mRNA to paranodal regions. These functions are critical for saltatory conduction and normal sensory transmission. PRX mutations cause a spectrum of demyelinating neuropathies, including Charcot-Marie-Tooth disease types 1, 3, 4, and 4F, as well as autosomal dominant cerebellar ataxia and slowed nerve conduction velocity 1. At the population level, gnomAD v4.1 classifies this gene as LoF-tolerant (LOEUF=1.32); however, this is distinct from clinical pathogenicity—ClinVar documents 89 pathogenic or likely pathogenic variants. PRX also plays a role in remyelination after nerve injury and supports normal lens fiber cell morphology. Currently, no disease-modifying treatments specifically targeting PRX dysfunction have been approved; management remains symptomatic.