The Relationship Between Autism Spectrum Disorder and Telomere Length
Autism spectrum disorder (ASD) is the fastest growing neurodevelopmental disorder in the United States, affecting as many as 1 in 59 children. Little is known regarding causes or targetable treatments. A newly explored area in ASD is length of telomeres, a non-coding DNA nucleotide sequence which caps chromosomes. Two studies demonstrated an association between shortened telomere length (TL) and ASD. Shorter TL is also associated with cognitive dysfunction in age-related and neurological disorders. We examined relationships between TL and cognition in both children with ASD and their parents. We hypothesized: 1) children with ASD will have shorter TL compared to neurotypical children, and 2) TL will be positively associated with cognitive function in children with ASD and their parents. Although a prior report of TL in ASD found no association with core symptoms (social communication impairments and restricted, repetitive behaviors or interests), we explored these domains as well. We hypothesized TL would not be associated with core symptoms in children with ASD or their parents. We used Quantitative Polymerase Chain Reaction (qPCR) assay to measure TL. The sample size (all male) consisted of: Controls n = 71, ASD n = 116, Parents n = 72. We found children with ASD had shorter TL than neurotypical children, and there was no relation between TL and cognitive function or core symptoms in children with ASD. TL in parents of children with ASD was positively associated with three domains of cognitive function: working memory (p=0.022), knowledge (p=0.008), and verbal (p=0.028), as well as full-scale IQ (p=0.029). TL was positively associated with a more aloof personality in parents, as measured by the Broader Autism Phenotype (BAP) questionnaire (p=0.002). Results confirm two previous findings: the association between shorter TL and children with ASD and no relationship between TL and core symptoms of ASD. Our novel findings provide the first evidence that longer TL in parents of children with ASD is associated with specific cognitive abilities and a BAP-related behavior. Further research will determine if TL is a biological mechanism of ASD and potential treatment target.