I have come across a case in which similar presenting issues were ultimately bound up with Gender Identity Disorder (GID). The experiences the client related which could produce PTSD may also have the effect of masking the more fundimental issue for the client, and one that also has strong components of distrust, guilt, shame, fear, anxiety, etc.
I reallize you weren't being exclusive about what to assess for, but you didn't really discuss it as a potential diagnosis in your reply (though it was mentioned (implied?) in the title of the question). It seems to me that GID should not be overlooked as a posibility during assessment, though a specialist could be necessary for an accurate diagnosis. Especially because, from the reading I have done, it is often coexistant with PTSD because of the often pervasive, negative reactions of others in the child's environment.
Many people have apparently been misdiagnosed for years before meeting a therapist who recognized this as a legitimate possibility.
I look forward to your thoughts about this possibility.