Another phenotypic distinction we are investigating is early-onset versus regressive autism
, as defined by the language and social regression questions on the ADI-R and the CDQ.
A team from the Wake Forest University School of Medicine in North Carolina are currently examining 275 children with regressive autism
and bowel disease.
Dr Richard Hyslop, GP at the Old Cole Surgery, in Bedworth, said: "Autism, including regressive autism
, was well-known long before MMR was used in this country.
Traver presented data showing that exposure to broad-spectrum antibiotics may be a trigger in the development of autism and findings that the intestinal microbiota of children with regressive autism
is disrupted with an increase in Clostridium and Ruminococcus species.
It provides no evidence to refute the Wakefield hypothesis of an association between MMR vaccine, regressive autism
following previously normal development, and a novel form of inflammatory bowel disease.
Researchers will also investigate possible treatments for autism, including the antibiotic minocycline in regressive autism
and the use of chelation therapy.
In the years since Dr Wakefield's claims not one epidemiological study has revealed a link between the vaccine and autism, even though parents of children with regressive autism
maintain they were damaged by the vaccinations.
"It makes me so angry, " she said: "My son has suffered typically regressive autism
after he had the DPT jabs in Australia, and fell seriously ill with chronic diarrhoea."
She said studies conducted on the issue had been based on large-scale populations and were 'too insensitive to pick up the rarer cases of regressive autism
with bowel disorder which some families are convinced may have been triggered by MMR'.
Tests carried out on children with regressive autism
have shown the presence of measles virus in the bowel, blood and spinal fluid, therefore in the brain.