# Whole-Genome Sequencing Identified a Novel Mutation in the N-Terminal Domain of KIF5A in Chinese Patients with Familial Amyotrophic Lateral Sclerosis

## TL;DR

A new mutation in the KIF5A gene was found in a Chinese family with ALS, showing different symptoms compared to similar cases in Europe.

## Contribution

Identification of a novel N-terminal KIF5A mutation in Chinese familial ALS patients, highlighting clinical heterogeneity.

## Key findings

- A rare KIF5A mutation (c.86A>G) was identified in a Chinese familial ALS proband.
- The mutation is located in the N-terminal domain, differing from previously reported C-terminal mutations in European ALS cases.
- Patients with this mutation showed delayed onset and extended survival, with initial symptoms in both upper limbs.

## Abstract

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by progressive damage to both upper and lower motor neurons. Genetic factors are known to play a crucial role in ALS, as genetic studies not only advance our comprehension of disease mechanisms but also help unravel the complex phenotypes exhibited by patients. To gain further insights into the genetic landscape of ALS in the Chinese population and explore genotype–phenotype correlations among individuals, we conducted whole-genome sequencing to screen genes in 34 Chinese familial ALS (FALS) probands lacking the most common ALS-associated genes. Within this cohort, we identified a rare heterozygous missense mutation in the N-terminal domain of KIF5A (c.86A>G) in one of the probands. This finding is significant as mutations in the KIF5A gene have been implicated in ALS in European cohorts since 2018, predominantly characterized by C-terminal mutations. Analysis of the clinical phenotype within this familial lineage revealed a delayed onset of symptoms, an extended survival duration, and initial manifestations in both upper limbs. These observations underscore the clinical heterogeneity observed in ALS patients harboring KIF5A mutations. In conclusion, our study contributes to the growing body of evidence linking KIF5A to ALS and enhances our understanding of the intricate genetic landscape of this disease.