Toni Braxton discovered her youngest son DIEZEL was autistic when officials at the four-year-old's school in Las Vegas alerted the soul singer to the extent of his learning difficulties. The UNBREAK MY HEART singer felt sure something was wrong when Diezel failed to progress like his older brother, DENIM, but doctors simply assured her the tot was a slow learner with a possible hearing problem. Braxton put her son in speech therapy classes, but had no idea he was autistic until the dean of his private school asked to speak to her late last year (06), shortly after she had begun her residency at Vegas' Flamingo hotel and casino complex. She recalls, "The dean called and said, 'You need to come pick him up, he's not ready for this school.' "I didn't know what to think... They gave us a card and said, 'Call (disability organisation) Child Find in Vegas,' and we called them and they are the one that diagnosed him being autistic."