Suppose in a very respectable and reputable family, there is a narcotic addicted young boy who is not acceptable by his family. Family are embarrassed to appear in public and social areas (like ceremonies and so on) just because of having such a child. They have attempted to make him quit, but all their efforts have been futile. Once the family daughter who's been driven mad at her brothers behaviors and is asked about her brother (e.g. by a close friend), wants to say "He is the black sheep of my family."
We all know the meaning, but I would be really thankful if one could tell me if I can replace black sheep with the word disgrace in this particular sense in the manner that I could convey exactly the same message?