This study investigates changes in the KIF5A gene, which plays a key role in moving materials within nerve cells. Mutations in this gene can lead to neurological diseases like hereditary spastic paraplegia (HSP), Charcot-Marie-Tooth disease (CMT2), and amyotrophic lateral sclerosis (ALS). By analyzing 390 Italian patients, the researchers found five individuals with harmful KIF5A mutations. Their symptoms and family histories helped clarify how different mutations affect the nervous system. This research improves understanding of how genetic differences in KIF5A lead to varied disease outcomes, which may help improve future diagnoses and guide treatment strategies. (By Dr. Rosangelka Ferese, https://jmg.bmj.com/content/early/2025/06/25/jmg-2025-110801 )