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 vaccination 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 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 the controversial book, “Evidence of Harm: Mercury in Vaccines and the Autism Epidemic,” Ms. 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 Ms. Wright’s remarks were denigrating.

So, in early June, Bob and Suzanne Wright repudiated their daughter on the charity’s Web site. “Katie Wright is not a spokesperson” for the organization, the Wrights said in a brusque statement. Her “personal views differ from ours.” The Wrights also apologized to “valued volunteers” who had been disparaged. Told by friends how cold the rebuke sounded, Mrs. Wright belatedly added a line saying, “Katie is our daughter, and we love her very much.”