Lisa Domican www.graceapp.com There was no single thunderbolt moment when I understood my son, Liam, was not like other children. No “I knew where I was when John Lennon was shot, or Man landed on the Moon.” Instead it came over a number of weeks in one difficult summer, when little things started to add up and my husband managed to convince me that it was time to look for help. Liam was a bright, happy and alert little boy and everyone loved him. He was obviously clever; leaning out of his stroller at 18 months to look at road signs. But sometime between his second and third birthdays, my husband started asking questions. Liam wasn’t talking, he wasn’t looking at anyone, he wasn’t answering to his name — he was leading us to the cupboard to get a drink, but not asking for it. I resisted at first. Liam…