PITTSBURGH — The parents of a 5-year-old autistic boy who died after receiving a chemical treatment sued the doctor who administered it for wrongful death.

Mawra and Rufai Nadama, who live in Great Britain, accused Dr. Roy Kerry of causing their son, Tariq, to die of cardiac arrest at Kerry's office in Portersville immediately after the boy received chelation therapy on Aug. 23, 2005.

Chelation removes heavy metals from the body and is approved by the Food and Drug Administration only for acute heavy-metal poisoning that has been confirmed by blood tests. Some people who believe autism is caused by a mercury-containing preservative once used in vaccines say chelation may also help autistic children.

Kerry of Greenville, Mercer County, did not immediately return a message left at his office Monday.

The Nadamas are also suing ApotheCure Inc., of Dallas, which they contend supplied the chelation solution but allegedly did not provide appropriate warnings and instructions about its use.

The company did not immediately return a call for comment.