ALS2-related disorders are considered a consequence of retrograde degeneration of upper motor neurons (UMN) of pyramidal tracts displaying a clinical continuum with infantile to juvenile onset and a recessive inheritance pattern, ranging from IAHSP (infantile ascending hereditary spastic paraplegia) and JPLS (juvenile primary lateral sclerosis), both primarily assigned to UMN, to JALS (juvenile amyotrophic lateral sclerosis), with additional lower motor neuron (LMN) involvement [1, 2]. The gene discussed is ALS2; the disease is juvenile primary lateral sclerosis.