Deep Phenotyping of the Broader Autism Phenotype in Epilepsy: A Transdiagnostic Marker of Epilepsy and Autism Spectrum Disorder

Abstract

Objective

We conducted deep and minimal phenotyping of the broader autism phenotype (BAP) in people with epilepsy (PWE) and compared its expression with published rates in the general population and relatives of individuals with autism spectrum disorder (ASD-relatives). We then examined the association of clinical epilepsy variables with BAP expression to explore its underpinnings in PWE.

Methods

103 adults with seizures (M_age = 37.37, SD = 12.50; 47% males; 51 temporal lobe epilepsy, 40 genetic generalized epilepsy, 12 other) and 58 community members (M_age = 39.59, SD = 14.56; 35% males) underwent deep phenotyping using the observer-rated Autism Endophenotype Interview and minimal phenotyping with the Broader Autism Phenotype Questionnaire (BAPQ). Published rates of the BAP were ascertained from large randomly selected samples (n > 100) of the general population and ASD-relatives based on BAPQ data.

Results

There was a higher rate of BAP in PWE (15% males, 27% females) compared with the general population (5% males, 7% females) and a similar rate to ASD-relatives (9% males, 20% females). Deep phenotyping identified an additional 22 males and 10 females, with the combined measures indicating elevated rates of the BAP in PWE (44% males, 36% females). Only a shorter duration of epilepsy was weakly correlated with BAP trait expression in males (r = − 0.21, p = 0.05).

Interpretation

PWE have a high rate of BAP, largely unrelated to secondary clinical epilepsy effects. The BAP may provide a trans-diagnostic marker of shared etiological mechanisms of epilepsy and ASD and partly account for psychosocial difficulties faced by PWE with childhood or adult onset of seizures.