KIF1A and Spasticity: A region such as that including p11, p24-p21, q33, and q37 is collated with HSP linkage by altering the receptor expression-enhancing protein-1 (SPG31/REEP1), spastin (SPG4/SPAST), Heat Shock Protein Family D (Hsp60) member 1 (SPG13/HSPD1), Kinesin Family Member 1A (SPG30/KIF1A) with frameshift [18], missense [20,21], and others including R11Q or S69L [22] in the heterozygous state to induce hyperreflexia plus spasticity and neuropathy.