please accept my deepest sympathy for your brother-in-law,, i too have a smilair story,, last year my gp and a neuro dr.. thought i had A.L.S.,, it floored me and my family,, it turns out that i had C.M.T. also a disk problem,,, maybe this will help you,,, i don't believe that A.L.S. is hereditory,,, please enjoy your new baby,,, and don't worry,,, relax.. life is too short,,, live well congrat's on your new addition,,,
.....twitching outside of ur fears could be as simple as having ur vitamin and mineral levels.....low magnessium and/ or potassium can cause the twitching. Have ur PC send u for labs.....and let him inform u of which suppliments u need and quanity.
stress can also do so many different things to our bodies, and with a new child, it could also be a source if ur issues.....try and relax...if u blink, the next time u look, ur child will be moving out!!...it goes so fast.....enjoy! : )
Good luck
Godspeed
"selma"