Could be wrong, but I don't think that is possible. Symptoms for all the ASDs, including Asperger's, need to be present in the early development period (before age 3) to my knowledge. They may have been missed at the time, but they'd still be there.
Adulthood onset occurs for disorders on the schizophrenia spectrum however. Schizotypal especially has a lot of overlap of symptoms but differs in that its onset is after 18 rather than before 3.
Are you absolutely sure there were no childhood symptoms? I think he's right bringing in a specialist, update us on what they find once you see them.