X-linked distal spinal muscular atrophy type 3 is a rare distal hereditary motor neuropathy characterized by slowly progressive atrophy and weakness of distal muscles of hands and feet with normal deep tendon reflexes or absent ankle reflexes and minimal or no sensory loss, sometimes mild proximal weakness in the legs and feet and hand deformities in males. The disease is Monarch Disease Ontology id MONDO_0010338 (X-linked distal spinal muscular atrophy type 3). Also known as: ATP7A spinal muscular atrophy, ATP7A-related distal motor neuropathy, DSMAX, SMAX3, X-linked dHMN type 3, X-linked dHMN3, X-linked dSMA type 3, X-linked dSMA3.