Adopting my baby brother...

My biological father, who’s been a functioning crack addict since the early 80’s and his present drug addict GF had my baby brother last December which resulted in my baby brother being taken by CPS and being placed in foster care. From the moment I found out, my wife and I have been trying to get custody of my baby brother. We’ve passed the local background checks, Home Study, and FBI finger printing as of this past Monday. But, my baby brothers GAL has expressed concern on the grounds of the fact that my baby brother has a medical condition and the fact that I’m in a same sex marriage. If anyone can give some sort of advice I’d really appreciate it.