Is there sexual dimorphism of hyperserotonemia in autism spectrum disorder?
High blood serotonin clusters in pre-pubertal boys with autism, hinting at sex-specific biology you should note during early assessment.
01Research in Context
What this study did
The team asked a simple question: do boys and girls with autism differ in blood serotonin levels?
They tested pre-pubertal and post-pubertal youth with autism. They noted who had high serotonin, a state called hyperserotonemia.
What they found
Before puberty, boys with autism were more likely than girls to have high serotonin. After puberty, the sex gap vanished.
In numbers, 42 percent of the young group showed high serotonin, and most were boys.
How this fits with other research
Hranilovic et al. (2007) first showed that autistic adults often have high serotonin. The new study moves the lens to kids and adds sex as a key detail.
Panahi et al. (2023) found another boy-linked marker—short telomeres—in the same age range. Both papers point to male-biased biology in early autism.
Cohen et al. (1990) showed that high serotonin runs in families. Taken together, the picture is: serotonin is heritable, rises higher in young autistic boys, and may flag a distinct developmental path.
Why it matters
If you assess young children with autism, know that high serotonin is more common in boys. This may guide medical work-ups or parent explanations. Track sex when you review lab results, and pair findings with developmental history rather than treating serotonin as a stand-alone sign.
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02At a glance
03Original abstract
Approximately 30% of individuals with autism spectrum disorder (ASD) have elevated whole blood serotonin (5-HT) levels. Genetic linkage and association studies of ASD and of whole blood 5-HT levels as a quantitative trait have revealed sexual dimorphism. Few studies have examined the presence of a sex difference on hyperserotonemia within ASD. To assess whether the rate of hyperserotonemia is different in males than in females with ASD, we measured whole blood 5-HT levels in 292 children and adolescents with ASD, the largest sample in which this biomarker has been assessed. Based upon previous work suggesting that hyperserotonemia is more common prior to puberty, we focused our analysis on the 182 pre-pubertal children with ASD. 42% of pre-pubertal participants were within the hyperserotonemia range. In this population, we found that males were significantly more likely to manifest hyperserotonemia than females (P = 0.03). As expected, no significant difference was found in the post-pubertal population. Additional work will be needed to replicate this intriguing finding and to understand whether it could potentially explain differences in patterns of ASD risk between males and females. Autism Res 2017, 10: 1417-1423. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
Autism research : official journal of the International Society for Autism Research, 2017 · doi:10.1002/aur.1791