Catecholaminergic metabolism and autism

The authors determined levels of dopamine (DA) and its derivatives homovanillic acid (HVA), 3-4 dihydroxyphenylacetic acid (DOPAC), 3 methoxytyramine and norepinephrine + epinephrine (NE + E) in the urine, and DA, E and NE in the whole blood of 50 autistic children aged between 1 year 11 months and 16 years. An association was tested for between markers coding for the enzymes and D3 dopaminergic receptor genes implicated in the monoaminergic pathway and autism, using restriction fragment-length polymorphism. There were significant modifications of catecholamine metabolites, but no difference for allele frequencies of the genes coding for tyrosine hydroxylase, dopamine beta hydroxylase and DRD3 in this population compared with a healthy school population matched for chronological age. However, some of the data encourage a more complete study of chromosome 11.