Urinary compounds in autism.
BACKGROUND: Although earlier claims to identify specific compounds in the urine of people with autism had been discredited, it was subsequently suggested that there might be biochemical characteristics that were specific to early childhood, particularly in those who also did not have a severe degree of intellectual disability This study was to establish whether autism might have a distinctive chromatographic profile on urinary analysis. METHOD: Thirty-four prepubertal boys with autism were matched with two groups of boys without autism--one on ability and chronological age and the other on chronological age alone, being within the normal range of ability. Laboratory analysis of their urine samples was carried out blind as to the clinical diagnosis. RESULTS: The analysis correctly identified 53% of the autism group as against misidentifying 33% and 18% of the other two groups. When children with a severe learning disability (both with and without autism) were excluded from the comparisons, the laboratory then identified 77% of the 13 boys left in the autism group and misidentified 8% and 18% of the other two groups. CONCLUSIONS: The results would support the idea of a biological marker in prepubertal children and that it may be absent in, or obscured by the presence of severe LD.