# A Japanese patient with hereditary spastic paraplegia with a rare KIF5A nonsense variant

## TL;DR

A Japanese family with hereditary spastic paraplegia is linked to a rare mutation in the KIF5A gene, which causes reduced gene activity and the disease.

## Contribution

Identification of a rare KIF5A nonsense variant as causative in a Japanese family with hereditary spastic paraplegia.

## Key findings

- A KIF5A nonsense variant (c.2590C>T) was found in a patient and family members with spastic paraplegia.
- The variant led to significantly decreased KIF5A mRNA expression compared to healthy controls.
- The variant was classified as pathogenic and causative of the disease in the family.

## Abstract

Spastic paraplegia (SPG)10 is an autosomal dominant SPG caused by kinesin family member 5A (KIF5A) gene variants. We describe a Japanese patient with SPG whose deceased mother and maternal uncle also exhibited SPG. Exome analysis identified a rare KIF5A nonsense variant (NM_004984.4:c.2590C>T (p.Arg864Ter)) in the patient, regarded as pathogenic. As KIF5A mRNA expression was significantly decreased compared with that of a healthy control, the variant was deemed causative of SPG.