Since you are here that mean one of your family member got this disorder..
It is bad, i know...!
But, still it could be worth, comparing with all other disorders this one is not that much bad, it can be controlled and managed by small pill (biotin) everyday and you will be fine.
Usually, you will go through a denial period at the beginning where we refuse to believe that this happen to us and then we go through some depression till we accept that this is reality and we have to live with it.
anyway, try to be strong and understand that if you really take it seriously it can be managed and the patient can live normal life with God Blessing
Wish you all the best