A year after their grandson Christian was diagnosed with autism in 2004, Bob Wright, the chairman of NBC/Universal, and his wife, Suzanne, founded Autism Speaks, a mega-charity dedicated to curing the neurological disorder that afflicts 1 of every 150 children in America today.

The Wrights' venture was also an attempt to end the internecine warfare in the world of autism — where some are convinced the disorder is genetic and best treated with intensive therapy, and others blame preservatives in vaccinations and swear by supplements and diet to cleanse the body of heavy metals.

With its high-powered board, world-class scientific advisers and celebrity fund-raisers such as Jerry Seinfeld and Paul Simon, the charity was a powerful voice, especially in Washington. It also made strides toward its goal of unity by merging with three existing autism organizations and raising millions of dollars for research into all potential causes and treatments. The Wrights call it the "big tent" approach.

But now the fissures in the autism community have made their way into the Wright family, where father and daughter are not speaking after a public battle with themes familiar to thousands of families with autistic children.

The Wrights' daughter, Katie, the mother of Christian, says her parents have not given enough support to the people who believe, as she does, that the environment — specifically a synthetic mercury preservative in vaccines — is to blame. No major scientific studies have linked pediatric vaccines and autism, but many parents and their advocates persist, and a federal "vaccine court" is now reviewing nearly 4,000 such claims.

The Wright feud has played out in cyberspace and spilled into Autism Speaks, where those who disagree with Katie Wright's views worry that she is setting its agenda. And the family intent on healing a fractured community has instead opened its old wounds and is, itself, riven.

The rift began in April when Katie Wright put herself squarely on the side of "The Mercurys," as that faction is known, on Oprah Winfrey, where she described how her talkative toddler turned unresponsive and out-of-control after his vaccines and only improved with unconventional, and untested, remedies.

In a Web interview with David Kirby, author of a controversial book, "Evidence of Harm: Mercury in Vaccines and the Autism Epidemic," Katie Wright lashed out at the "old guard" scientists and pioneering autism families. If the old-timers are unable to let go of "failed strategies," she said, they should "step aside" and let a new generation "have a chance to do something different with this money" that her parents' charity was dispensing.

Complaints poured in from those who said Katie Wright's remarks were denigrating.