kif5a genetic mutation

What a misleading phrasing. This phrasing does not mean "eh, it might be pathogenic, it might not be. We're not sure."

This phrasing actually means "This gene is significant, we just don't know how significant yet."

The plain language version of what my geneticist has explained:

• The KIF5A gene is found in plants, mammals, fish, etc. That means it's probably part of the DNA code that allows us to be living beings.
• The KIF5A gene has extremely low tolerance. This means that in all those billions of organisms, the KIF5A gene always looks the same. When it doesn't, that DNA doesn't continue in the gene pool. This could mean it affects fertility, or it could mean it's a lethal gene, or something in between. There's a lot of possible implications, but overall it means that KIF5A has a pretty important function.
• KIF5A is associated with Spastic Paraplegia, Charcot Marie Tooth, and ALS. Those three diseases have similar mechanisms and effects, if at different severities. Neurological dysfunction is correlated here somehow, but is it causal?
• No one seems to be able to tell me if they've found any asymptomatic individuals with KIF5A mutations.