TY - JOUR
T1 - Neuroanatomic alterations and social and communication deficits in monozygotic twins discordant for autism disorder
AU - Mitchell, Shanti R.
AU - Reiss, Allan L.
AU - Tatusko, Danielle H.
AU - Ikuta, Ichiro
AU - Kazmerski, Dana B.
AU - Botti, Jo Anna C.
AU - Burnette, Courtney P.
AU - Kates, Wendy R.
PY - 2009
Y1 - 2009
N2 - Objective: Investigating neuroanatomic differences in monozygotic twins who are discordant for autism can help unravel the relative contributions of genetics and environment to this pervasive developmental disorder. The authors used magnetic resonance imaging (MRI) to investigate several brain regions of interest in monozygotic twins who varied in degree of phenotypic discordance for narrowly defined autism. Method: The subjects were 14 pairs of monozygotic twins between the ages of 5 and 14 years old and 14 singleton ageand gender-matched typically developing comparison subjects. The monozygotic twin group was a cohort of children with narrowly defined autistic deficits and their co-twins who presented with varying levels of autistic deficits. High-resolution MRIs were acquired and volumetric/area measurements obtained for the frontal lobe, amygdala, and hippocampus and subregions of the prefrontal cortex, corpus callosum, and cerebellar vermis. Results: No neurovolumetric/area differences were found between twin pairs. Relative to typically developing comparison subjects, dorsolateral prefrontal cortex volumes and anterior areas of the corpus callosum were significantly altered in autistic twins, and volumes of the posterior vermis were altered in both autistic twins and co-twins. Intraclass correlation analysis of brain volumes between children with autism and their co-twins indicated that the degree of within-pair neuroanatomic concordance varied with brain region. In the group of subjects with narrowly defined autism only, dorsolateral prefrontal cortex, amygdala, and posterior vermis volumes were significantly associated with the severity of autism based on scores from the Autism Diagnostic Observation Schedule - Generic. Conclusions: These findings support previous research demonstrating alterations in the prefrontal cortex, corpus callosum, and posterior vermis in children with autism and further suggest that alterations are associated with the severity of the autism phenotype. Continued research involving twins who are concordant and discordant for autism is essential to disentangle the genetic and environmental contributions to autism.
AB - Objective: Investigating neuroanatomic differences in monozygotic twins who are discordant for autism can help unravel the relative contributions of genetics and environment to this pervasive developmental disorder. The authors used magnetic resonance imaging (MRI) to investigate several brain regions of interest in monozygotic twins who varied in degree of phenotypic discordance for narrowly defined autism. Method: The subjects were 14 pairs of monozygotic twins between the ages of 5 and 14 years old and 14 singleton ageand gender-matched typically developing comparison subjects. The monozygotic twin group was a cohort of children with narrowly defined autistic deficits and their co-twins who presented with varying levels of autistic deficits. High-resolution MRIs were acquired and volumetric/area measurements obtained for the frontal lobe, amygdala, and hippocampus and subregions of the prefrontal cortex, corpus callosum, and cerebellar vermis. Results: No neurovolumetric/area differences were found between twin pairs. Relative to typically developing comparison subjects, dorsolateral prefrontal cortex volumes and anterior areas of the corpus callosum were significantly altered in autistic twins, and volumes of the posterior vermis were altered in both autistic twins and co-twins. Intraclass correlation analysis of brain volumes between children with autism and their co-twins indicated that the degree of within-pair neuroanatomic concordance varied with brain region. In the group of subjects with narrowly defined autism only, dorsolateral prefrontal cortex, amygdala, and posterior vermis volumes were significantly associated with the severity of autism based on scores from the Autism Diagnostic Observation Schedule - Generic. Conclusions: These findings support previous research demonstrating alterations in the prefrontal cortex, corpus callosum, and posterior vermis in children with autism and further suggest that alterations are associated with the severity of the autism phenotype. Continued research involving twins who are concordant and discordant for autism is essential to disentangle the genetic and environmental contributions to autism.
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U2 - 10.1176/appi.ajp.2009.08101538
DO - 10.1176/appi.ajp.2009.08101538
M3 - Article
C2 - 19605538
AN - SCOPUS:68149091908
SN - 0002-953X
VL - 166
SP - 917
EP - 925
JO - American Journal of Psychiatry
JF - American Journal of Psychiatry
IS - 8
ER -