anne:
your daughter must be at least 20 years of age if she is having children of her own. if she has never shown any symptoms by now, its a sure bet that she does not have thomsens. you are born with this, and it can not skip a generations, therefore your grandchildren have no fear of getting it either. there are some simple tests that you can do at home. first: clench your hand in a fist for about a minute and then release. the fingers will want to re-curl and this can be painfull for a second. another good test, is to close your eyes very tight and squeeze them shut, open them and sqeeze tight again. if after doing this several times your eyes can hardly open, then you have myatonia. i think your daughter has nothing to fear.
hope i was of some help. rhonda