Except that the purpose of marriage in the Orthodox Church-- also part of the Judeo-Christian tradition--is not procreation. Also, some gay marriages protect children already born and allow the other partner to adopt them for the first time. Surely this can be considered supporting family, not overturning it. 

It is still difficult to see how the dilemma facing a transgendered person regarding sexual reassignment (or the parent of that young person) incites marriage breakdown. The notion itself suggests an unfamiliarity with how either situation works.