Data from: A quantitative electrophysiological biomarker of duplication 15q11.2-q13.1 syndrome

Background: Duplications of 15q11.2-q13.1 (Dup15q syndrome) are highly
penetrant for autism spectrum disorder (ASD). A distinct
electrophysiological (EEG) pattern characterized by excessive activity in
the beta band has been noted in clinical reports. We asked whether EEG
power in the beta band, as well as in other frequency bands, distinguished
children with Dup15q syndrome from those with non-syndromic ASD and then
examined the clinical correlates of this electrophysiological biomarker in
Dup15q syndrome. Methods: In the first study, we recorded spontaneous EEG
from children with Dup15q syndrome (n = 11), age-and-IQ-matched children
with ASD (n = 10) and age-matched typically developing (TD) children (n =
9) and computed relative power in 6 frequency bands for 9 regions of
interest (ROIs). Group comparisons were made using a repeated measures
analysis of variance. In the second study, we recorded spontaneous EEG
from a larger cohort of individuals with Dup15q syndrome (n = 27) across
two sites and examined age, epilepsy, and duplication type as predictors
of beta power using simple linear regressions. Results: Spontaneous beta1
(12 – 20 Hz) and beta2 (20 – 30 Hz) power were significantly higher in
Dup15q syndrome compared with both comparison groups, while delta (1 – 4
Hz) was significantly lower than both comparison groups. Effect sizes in
all three frequency bands were large (|d| > 1). In the second
study, we found that beta2 power was significantly related to epilepsy
diagnosis in Dup15q syndrome. Conclusions: Here, we have identified an
electrophysiological biomarker of Dup15q syndrome that may facilitate
clinical stratification, treatment monitoring, and measurement of target
engagement for future clinical trials. Future work will investigate the
genetic and neural underpinnings of this electrophysiological signature as
well as the functional consequences of excessive beta oscillations in
Dup15q syndrome.