WHEN DOES AUTISM START?

And thinking early. Today many kids aren't getting treatment until well after their 3rd birthdays. Diagnosing an infant with autism at 6 months or a year--maybe even one day in the delivery room--could mean the difference between baby steps and giant leaps. At the Kennedy Krieger Institute in Baltimore, a handful of 2-year-olds toddle at the next frontier in autism treatment. The children are part of an NIH-funded study run by Rebecca Landa to see if early intervention, before the age of 3, can improve the trajectory of cognitive and social development. As Landa looks on, David Townsend fusses and stamps his feet. Then, he notices his twin sister, Isabel, turning the pages of "Ten Little Ladybugs." David looks at Isabel, watches her hands, then flips a page himself, accomplishing what autism experts call "joint engagement." "That was beautiful," says Landa. A fleeting moment, a developmental milestone--and, if all goes well, a new world of possibilities for a sweet little boy with dimples.

Autism on NBC

If you want to learn more, tune in to these programs from Feb. 21 to Feb. 25. "Today": Five days of coverage at 7 a.m., ET: adults with autism, sibling stress, legal hurdles and more.

"NBC Nightly News": Three reports from Robert Bazell, including leading-edge research, at 6:30 p.m., ET.

MSNBC: Live interviews with autism experts and parents of autistic children, daily at 10:30 a.m., ET