Family-Based Association Testing of OCD-associated SNPs of SLC1A1 in an autism sample.
A 2008 hunt for an OCD-linked gene in autism came up empty after proper stats.
01Research in Context
What this study did
The team looked at one gene, SLC1A1, in families who had a child with autism.
Small DNA changes in this gene had already been tied to obsessive-compulsive disorder (OCD).
They asked: do these same gene changes also show up more often in kids with autism?
What they found
One version of the gene, the G allele, appeared a bit more under a recessive model.
After fixing for multiple tests, the link vanished. The signal was too weak to trust.
Bottom line: the OCD-linked gene did not clearly travel with autism in this sample.
How this fits with other research
Hertz-Picciotto et al. (2018) later summed up many studies and said autism risk is a soup of many genes plus environment. Our 2008 single-gene result fits that soup story: one ladle of SLC1A1 barely flavors the broth.
Norris et al. (2012) and Albert et al. (2024) show that how we slice autism behavior—factor shapes on the ADOS—still shifts with age and module. Weak gene findings like ours help explain why behavior, not a DNA spot, still drives daily assessment.
Greer et al. (2014) found that even kids with ADHD carry separate social and rigidity factors, mirroring autism. Their work and ours both warn against hunting one gene or one checklist score to explain overlapping neurodevelopmental traits.
Why it matters
You can stop waiting for a quick genetic test for autism. Keep running thorough ADOS-2 and parent interviews. When families ask about DNA, tell them we have clues but no single answer yet. Focus your energy on teaching skills, not on chasing unproven gene reports.
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02At a glance
03Original abstract
Reports identified the neuronal glutamate transporter gene, SLC1A1 (OMIM 133550, chromosome 9p24), as a positional and functional candidate gene for obsessive-compulsive disorder (OCD). The presence of obsessions and compulsions similar to OCD in autism, the identification of this region in a genome-wide linkage analysis of individuals with autism spectrum disorders (ASDs), and the hypothesized role of glutamate in ASDs make SLC1A1 a candidate gene for ASD as well. To test for association between SLC1A1 and autism, we typed three single nucleotide polymorphisms (SNPs, rs301430, rs301979, rs301434) previously associated with OCD in 86 strictly defined trios with autism. Family-Based Association Tests (FBAT) with additive and recessive models were used to check for association. Additionally, an rs301430-rs301979 haplotype identified for OCD was investigated. FBAT revealed nominally significant association between autism and one SNP under a recessive model. The G allele of rs301979 was undertransmitted (equivalent to overtransmission of the C allele under a dominant model) to individuals with autism (Z=-2.47, P=0.01). The G allele was also undertransmitted in the T-G haplotype under the recessive model (Z=-2.41, P=0.02). Both findings were also observed in the male-only sample. However, they did not withstand correction for multiple comparisons.
Autism research : official journal of the International Society for Autism Research, 2008 · doi:10.1002/aur.11