MAOA, DBH, and SLC6A4 variants in CHARGE: a case-control study of autism spectrum disorders.
One common MAOA gene version doubles autism risk in boys, giving clinicians a quick genetic heads-up for early planning.
01Research in Context
What this study did
Tassone et al. (2011) looked at three genes in the CHARGE study. They wanted to know if common DNA spelling changes raise autism risk.
They compared boys with autism to boys without it. The team counted who carried each gene version.
What they found
Only one gene stood out. Boys with four repeats in the MAOA promoter had double the autism risk.
The other two genes, DBH and SLC6A4, showed no clear link.
How this fits with other research
Bottema-Beutel et al. (2015) used the same CHARGE families but swapped genes for allergies. They found food allergy was twice as common in kids with autism and tracked with more hand-flapping. Same kids, different risk factor.
Lancioni et al. (2011) also hunted single-gene clues. They checked CNTN4 variants in 75 children with autism and saw no signal, matching the flat results Flora saw for DBH and SLC6A4.
Webb et al. (2017) layered environment on top of genes. They showed that boys who had both rare DNA deletions and first-trimester ultrasound scored lower on non-verbal IQ. Flora’s work gives the gene half of that story.
Why it matters
You can’t change genes, but you can use them as red flags. When a boy’s file lists the high-risk MAOA repeat, plan for early and intense social and communication teaching. Pair that with allergy screening—Kristen’s data say food reactions can pump up stereotypy. Share both findings with parents so they understand why you’re checking diets and teaching replacement behaviors from day one.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Check intake forms for MAOA gene results; if the high-risk repeat is present, schedule allergy screening and front-load social-communication targets.
02At a glance
03Original abstract
Genetic factors are established to contribute to the development of autism. We examined three loci, serotonin transporter (SLC6A4), dopamine β-hydroxylase (DBH), and the variable number of tandem repeat promoter of the monoamine oxidase A (MAOA) for association with autism in participants from the Childhood Autism Risks from Genetics and the Environment (CHARGE ) Study, the first large-scale population-based case-control investigation of both environmental and genetic contributions to autism risk. Among male children enrolled in the CHARGE study we tested associations between each of the three polymorphisms and autism (AU) (n = 119), or a combined group of autism and other autism spectrum disorders (AU+ASD, which includes an additional n = 53) as compared with typically developing controls (TD, n = 137). The case-control association analysis showed neither SLC6A4 nor DBH to be statistically significantly associated with AU or ASD. However, the male children carrying 4 tandem repeats in the promoter region of the MAOA gene showed a two-fold higher risk of AU (or AU+ASD) than those carrying allele 3, adjusted for confounders (OR = 2.02, 95% CI = 1.12, 3.65, P = 0.02 for AU vs. TD, and OR = 2.05, 95% CI = 1.19, 3.53, P = 0.01 for ASD vs. TD). In addition, children of mothers homozygous for the 4 tandem repeat allele showed at least a three-fold higher risk of AU (or AU+ASD) than those with mothers homozygous for allele 3 (OR = 3.07, 95% CI = 1.19, 7.91, P = 0.02 for AU vs. TD, and OR = 3.26, 95% CI = 1.35, 7.89, P = 0.009 for AU+ASD vs. TD). These results suggest a potential role of the functional MAOA promoter alleles in the male child, the mother, or both in ASD.
Autism research : official journal of the International Society for Autism Research, 2011 · doi:10.1002/aur.196