Can you tell me more about this? I think I'm facing this situation - it increasingly feels some kind of half-ASD, half-NPD that makes my domestic life less than ideal.
I'm no expert but suspect the empathy deficits present differently. Seems more willful on the part of the NPD, perhaps. With ASDs, it's often a case of not being self-aware enough to know how you come across, but once pointed out, it can be helpful to know. The narcissist may not even care? The subject of this article, to his credit, may not be the norm. And there are other differentiating factors. Along with autism comes certain sensory issues.
The best explanation I can provide is one that won't provide you much immediate info or relief. You and your partner would want to see a psychologist or PsyD, preferably with both a clinical and diagnostic background for counseling. At some point if your partner is NPD you're going to be made aware of it. Everything until that point will have been the easy part.