DYNC1H1-related disorders are primarily characterized by an axonal neuropathy with a wide phenotypic spectrum ranging from a neuromuscular-only phenotype (DYNC1H1-related neuromuscular disorder, or DYNC1H1-NMD) to phenotypes involving both the central nervous system and peripheral nervous system referred to collectively as DYNC1H1-related neurodevelopmental disorder (DYNC1H1-NDD). DYNC1H1-NMD manifestations are limited to the peripheral nervous system and characterized predominantly by motor neuropathy initially most pronounced in the lower limbs; muscle weakness and atrophy variably associated with foot deformities, contractures, and other skeletal involvement; and/or delayed motor milestones. DYNC1H1-NDD manifestations include motor axonal neuropathy and often global developmental delay / intellectual disability, epilepsy, neurobehavioral/psychiatric manifestations, and movement disorders with or without malformations of cortical development and/or microcephaly. In an individual with more significant central nervous system involvement, the motor axonal neuropathy may not be evident clinically and, thus, is only detected on further evaluation such as electrophysiologic testing. [from GeneReviews]