title: Head circumference and height in autism: a study by the Collaborative Program of Excellence in Autism.
abstract: Data from 10 sites of the NICHD/NIDCD Collaborative Programs of Excellence in Autism were combined to study the distribution of head circumference and relationship to demographic and clinical variables. Three hundred thirty-eight probands with autism-spectrum disorder (ASD) including 208 probands with autism were studied along with 147 parents, 149 siblings, and typically developing controls. ASDs were diagnosed, and head circumference and clinical variables measured in a standardized manner across all sites. All subjects with autism met ADI-R, ADOS-G, DSM-IV, and ICD-10 criteria. The results show the distribution of standardized head circumference in autism is normal in shape, and the mean, variance, and rate of macrocephaly but not microcephaly are increased. Head circumference tends to be large relative to height in autism. No site, gender, age, SES, verbal, or non-verbal IQ effects were present in the autism sample. In addition to autism itself, standardized height and average parental head circumference were the most important factors predicting head circumference in individuals with autism. Mean standardized head circumference and rates of macrocephaly were similar in probands with autism and their parents. Increased head circumference was associated with a higher (more severe) ADI-R social algorithm score. Macrocephaly is associated with delayed onset of language. Although mean head circumference and rates of macrocephaly are increased in autism, a high degree of variability is present, underscoring the complex clinical heterogeneity of the disorder. The wide distribution of head circumference in autism has major implications for genetic, neuroimaging, and other neurobiological research.
authors.affiliation: Department of Psychiatry, The Brain Institute at the University of Utah, Salt Lake City, Utah 84108, USA. janet.lainhart@hsc.utah.edu
authors.forename: Janet E
authors.initials: JE
authors.lastname: Lainhart
authors.forename: Erin D
authors.initials: ED
authors.lastname: Bigler
authors.forename: Maureen
authors.initials: M
authors.lastname: Bocian
authors.forename: Hilary
authors.initials: H
authors.lastname: Coon
authors.forename: Elena
authors.initials: E
authors.lastname: Dinh
authors.forename: Geraldine
authors.initials: G
authors.lastname: Dawson
authors.forename: Curtis K
authors.initials: CK
authors.lastname: Deutsch
authors.forename: Michelle
authors.initials: M
authors.lastname: Dunn
authors.forename: Annette
authors.initials: A
authors.lastname: Estes
authors.forename: Helen
authors.initials: H
authors.lastname: Tager-Flusberg
authors.forename: Susan
authors.initials: S
authors.lastname: Folstein
authors.forename: Susan
authors.initials: S
authors.lastname: Hepburn
authors.forename: Susan
authors.initials: S
authors.lastname: Hyman
authors.forename: William
authors.initials: W
authors.lastname: McMahon
authors.forename: Nancy
authors.initials: N
authors.lastname: Minshew
authors.forename: Jeff
authors.initials: J
authors.lastname: Munson
authors.forename: Kathy
authors.initials: K
authors.lastname: Osann
authors.forename: Sally
authors.initials: S
authors.lastname: Ozonoff
authors.forename: Patricia
authors.initials: P
authors.lastname: Rodier
authors.forename: Sally
authors.initials: S
authors.lastname: Rogers
authors.forename: Marian
authors.initials: M
authors.lastname: Sigman
authors.forename: M Anne
authors.initials: MA
authors.lastname: Spence
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Stodgell
authors.forename: Fred
authors.initials: F
authors.lastname: Volkmar
mesh_terms: D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000175:diagnosis / Q000473:pathology* / Q000523:psychology; D001827:Body Height; D016022:Case-Control Studies; D002508:Cephalometry; D002648:Child; D002675:Child, Preschool; D003299:Cooperative Behavior; D019465:Craniofacial Abnormalities / Q000473:pathology; D005260:Female; D006257:Head / Q000473:pathology*; D006801:Humans; D007360:Intelligence; D008297:Male; D008875:Middle Aged; D009316:National Institutes of Health (U.S.); D010290:Parents; D012016:Reference Values; D035781:Siblings; D012959:Socioeconomic Factors; D014481:United States