The story

When her son Justin was a newborn, Shannon Kinninger looked up from the kitchen where she was washing dishes, and saw a large, heavy toy fall on his head. Justin didn't cry.

Kinninger thought that was odd, and it wasn't the only thing that seemed strange about Justin. At her weekly playgroup, she watched the other babies hit their developmental milestones more or less on schedule. Justin lagged far behind.

"When he was supposed to be sitting up, he wasn't sitting up. When he was supposed to be holding his head up, he wasn't holding his head up. When he was supposed to be rolling over, he wasn't rolling over," says Kinninger, a nurse who lives in Fayetteville, Georgia.

Kinninger brought up her concerns to her pediatrician, but he told her not to worry. "The doctor kept saying that boys develop more slowly than girls," she says. "He kept reassuring me he'd be OK."

Even though she felt frustrated, Kinninger accepted this explanation for years. Finally, when Justin was 4, she decided enough was enough. Justin wasn't potty trained, and he had unusual repetitive behaviors, such as switching lights on and off for extended periods of time, or washing his hands over and over. Plus, he wouldn't look at people -- he looked "through" them. Read full article »

Elizabeth Cohen is a correspondent with CNN Medical News. Senior producer Jennifer Pifer and intern Jennifer Kabak contributed to this report.

Don't Miss

Health Library