The day that Marcus was diagnosed, ?all I wanted to do, as I was sitting there crying, was to just bury my head in my son’s chest and hug him, which I tried to do and he kind of broke free away from me and went to go play with the cars,? Erin said. ..Since Brendan was young, he lined these cars up on the side of the bathtub very precisely. It made Erin and Colm nervous, because that is something Marcus did around the time he was diagnosed with autism. That repetitive, obsessive behavior is a classic sign of autism, but as it turned out Brendan was merely imitating his brother, Marcus.