Urinary compounds in autism.

The team collected morning urine from prepubertal boys with autism. They ran each sample through a lab machine that separates chemicals by size. The goal was to see if the pattern of peaks could flag autism without using IQ tests or checklists.

The urine print caught 77 out of every 100 boys who had autism. It wrongly labeled only 8 to 18 out of every 100 typical boys. The pattern was clearest when boys with severe learning disability were left out.

Catania et al. (1982) saw a similar but weaker signal years earlier. Their test found only 54% of cases, so Burack et al. (2004) sharpened the tool by ruling out severe ID and using better lab gear.

Shandley et al. (2014) looks like a flat contradiction. They found no rise in urinary porphyrins and called the marker useless. The clash fades when you see they tested a different chemical family and used tighter age matching. Different analyte, different answer.

Rojahn et al. (2012) and Li et al. (2022) keep the urine hunt alive. J et al. swapped peptides for porphyrins and still saw a subgroup signal. Peiying et al. moved to pollutant metabolites and linked higher levels to worse autism scores. The matrix stays the same; the target keeps moving.

You can’t run a urine screen and stamp “autism” on a chart yet. Still, the 77% hit rate tells you biology leaves footprints before behavior fully shows. When parents ask about lab tests, you can say some urinary patterns line up with autism, but none are ready to replace ADOS. Keep an eye on future reviews like Baker et al. (2025) that will tell us when a marker is solid enough for clinic use.