Protecting DNA: Shortened Telomere Length Is Associated with Autism Spectrum Disorder

Background: Autism Spectrum Disorder (ASD) is a common neurodevelopmental disorder, but the etiology of symptoms in most cases is not well understood. Recently, two papers introduced preliminary evidence associating shortened telomere length with ASD. Telomeres are repetitive non-coding DNA nucleotides that protect genes by capping chromosome ends. They progressively shorten with each cell division, providing a biological measure of aging. Shortened telomeres have been associated with many adverse health and age-related outcomes such as cancer and Alzheimer’s disease. How telomere length may underlie symptoms associated with ASD is not well understood.

Objectives: We aimed to replicate the association of shortened telomere length with ASD in a large, well-characterized sample of children. We hypothesized children with ASD would have shorter RTL than age-matched typically developing (TD) controls.

Methods: Using blood leukocytes, we investigated the association between relative telomere length (RTL) and childhood ASD in males (ASD: n = 186; TD: n = 107). We used an established quantitative polymerase chain reaction method, and designed telomere and single-copy reference gene primers from an established protocol. We assessed RTL between groups using independent samples t-test (p < 0.05; one-tailed).

Results: With a subset of the entire sample (ASD: n = 31; TD: n = 28), who were well matched in age (ASD: 5.79±2.12 years; TD: 5.93±2.71 years), preliminary findings demonstrate that the ASD group had shorter RTL length compared to the controls [t(57) = 1.69, p = 0.04]. Continued analysis of the entire sample and correlational analyses with behavioral measures are in progress.

Conclusions: Findings replicated other recent studies, providing additional evidence that ASD is associated with shortened telomere length. Further investigations aimed at understanding the relationship between telomere length and symptoms associated with ASD are planned and warranted. Telomere length may be an important biological mechanism in understanding the etiology of ASD, and providing a novel treatment target for future interventions.