Spinal Muscular Atrophy with Lower Extremity Predominant 1, also known as spinal muscular atrophy with lower extremity predominance 1, is related to spinal muscular atrophy with lower extremity predominant and spinal muscular atrophy, lower extremity-predominant, 1, autosomal dominant. An important gene associated with Spinal Muscular Atrophy with Lower Extremity Predominant 1 is DYNC1H1 (Dynein Cytoplasmic 1 Heavy Chain 1). Related phenotypes are nervous system and growth/size/body region