Abstract
Persons with autism spectrum disorders (ASDs) often display low levels of melatonin, and it has been suggested that this decrease may be due to low activity of the acetylserotonin O-methyltransferase (ASMT), the last enzyme in the melatonin synthesis pathway. Moreover, genetic variants in ASMT have been associated with autism, as well as with low ASMT activity and melatonin levels, suggesting that the low ASMT activity observed in autism may partly be due to variation within the ASMT gene.
In this study, we present a symptom-based approach to investigate possible associations between ASMT and autistic-like traits (ALTs) in the general population. To this end, continuous measures of ALTs were assessed in a nationally representative twin cohort (n=1771) from Sweden and six Single Nucleotide Polymorphisms (SNP) and a duplication of exon 2 to 8 in ASMT were genotyped. Our results show a nominally significant association, in girls, between one SNP (rs5949028) in the last intron of ASMT and social interaction impairments. No significant association, however, was observed with traits related to language impairment or restricted and repetitive behavior.
In conclusion, our results support the possible involvement of the ASMT gene in ASDs and our finding that only one of three traits shows association suggests that genetic research may benefit from taking a symptom-specific approach to identify genes involved in autism psychopathology.
