A recently publicized theory that vampires may have been victims of a rare genetic disorder and drank blood to treat their illness has been disputed by doctors treating modern-day patients with the same disease.

"That's total hogwash and absolutely wrong," contends Dr. Neville Pimstone, an expert on a group of diseases known as porphyrias, associated with a malfunction in the biochemical production of heme, the red pigment in blood.

Pimstone, chief of gastroenterology at the University of California at Davis' School of Medicine, says that drinking blood would be useless, but that new research suggests that drinking a charcoal-containing solution helps victims of a rare and severely disfiguring form of porphyria.

There are only about 100 people worldwide today with the most severe form of the disease. They may become grotesquely disfigured because toxic chemicals, porphyrins, accumulate in the body, destroying skin tissue and sometimes mutilating faces and fingers.

At a recent scientific meeting, Canadian chemist David Dolphin suggested that the legendary "blood-drinking vampires were, in fact, victims of porphyria trying to alleviate the symptoms of their dreadful disease."

"That myth has to be thrown out the window," said Pimstone, who argues that blood consumed orally would be broken down in the intestinal tract and of no therapeutic value to the victims. He said his studies also found intravenous injections of blood to be of limited value in treating porphyria.

Instead, says Pimstone, research he has presented at three recent scientific meetings supports use of a charcoal-containing drink that helps rid the body of hazardous porphyrins in people with the severe form of the disease. Orally activated charcoal is already used to treat drug overdoses and accidental poisonings.

Pimstone said publicity about Dolphin's theory has "stigmatized all porphyrics." Most victims have milder forms of the disease and no symptoms, noted Pimstone, adding that he has seen hundreds of patients and that "there is no urge to drink blood."

He acknowledged that there might be some truth to suggestions linking porphyria victims of old to legends about werewolves, because werewolves could have included "abnormal-looking people with mutilations of any sort."