Clinical research
The 2013 cohort that mapped the spectrum
What happened
Before the trial, the same research group studied 93 children with autism and measured how common folate receptor autoantibodies were across the spectrum.
What it looked like
A clinic population of autistic children, most of whom had never had their folate transport questioned.
What the labs found
75.3% of the children tested positive for FRAAs. In the 16 children who had spinal fluid sampled, every single one had a CSF folate level below the normative mean — brain folate running low even where blood folate had not raised alarms.
What changed
This open-label work (outcomes were parent-rated, and the later meta-analysis sometimes cited as independent was co-authored by the same researcher — this entry does not count it as independent) built the case for the controlled trial in entry 13. It is included because it shows the spectrum clearly: this is common enough to test for, and variable enough to need trials, not testimonials.
The test that told the story
FRAA testing (with CSF 5-MTHF in a subset).
Sources: Frye et al. 2013 cohort study.