Before this study was made, 24 patients had been reported with de novo heterozygous variants affecting the motor domain of KIF1A protein and the functional impact of these variants was demonstrated by Lee et al. The main clinical features reported were moderate to severe developmental delay, cerebellar atrophy, optic nerve atrophy, progressive spasticity affecting lower limbs, and peripheral neuropathy [19]. The gene discussed is KIF1A; the disease is peripheral neuropathy.