A KIF5A Motor Domain Pathogenic Variant Associated with Spastic Paraplegia Type 10 and Demyelination

Spastic paraplegia type 10 is an autosomal dominant disease caused by KIF5A gene pathogenic variants. It commonly presents as pure spastic paraplegia but occasionally appears associated with polyneuropathy, cognitive impairment, parkinsonism, cerebellar ataxia, retinitis pigmentosa or deafness. The gene KIF5A codifies the kinesin-1 heavy chain, a protein with three main parts (globular motor domain, alfa-helical stalk and C-terminal tail). Its complete genotype-phenotype is still unclear however, some degree of correlation has been seen between motor domain variations and SPG10 and Charcot-Marie-Toth type 2. The other domains are mainly associated with amyotrophic lateral sclerosis and neonatal intractable myoclonus. We present a case of a KIF5A gene motor domain disease-causing variant with white matter lesions and SPG10. Unlike the other parts of the protein, pathogenic variants of the motor domain have not been associated with white matter lesions. We believe this case contributes to further uncover the phenotypical spectrum of KIF5A related disorders.