Loss of feeling in the skin

I am a little worried because my mother died of Motor neurone disease 3 years ago now and I have recently acquired one of her early symptoms.

I have a numb spot on the lower part of my index finger which you could stick pins in and I can't feel the pain only a bit of pressure.  There is a terrible itch under the skin but if you try and itch it where you think it is it is like I am itching someone else. I can move my finger with no trouble and the end of the finger has its complete sensations.
There is also a spot on my hand that if I rub it causes pins and needles in this area of my finger.  

Do you think that this is just a trapped nerve and I am paranoid or can MND be inherited?


Thanks

Shirley