I Am 62 Year Old Female. My Younger Sister Died

I am 62 year old female. My younger sister died at 52 having a muscle desease dermitomyocytis only weighing 32 pounds. My brother one year older then me died of Lou Gehrigs at 64. I am in the middle. i have been having night screams that now do not wake me up, about once a week. Could this be a symptom of the beginning of ALS.
YYYY@YYYY