Broader autism phenotype: evidence from a family history study of multiple-incidence autism families

Abstract

1997; 154:185-190)

Early Head Growth in Infants at Risk of Autism: A Baby Siblings Research Consortium Study

“…16, 41 Indeed, a recent analysis of HC from the California Autism Twin Study indicates that rates of macrocephaly are 20-27%, with no differences among probands with ASD, concordant and discordant co-twins. 53 Studies reporting HC in relatives have generally not included data regarding other relevant phenotypes (e.g., subthreshold symptoms), so it is difficult to know whether increased rates of macrocephaly are due to non-specific familial correlations in HC 42 or represent co-segregation of macrocephaly and behavioral symptoms of the ‘broader autism phenotype,’ 43, 44 presumably due to the expression of genes involved in susceptibility to ASD.…”

Predicting Social Impairment and ASD Diagnosis in Younger Siblings of Children with Autism Spectrum Disorder

“…The genetic risk to family members extends not only to diagnosed autism spectrum disorders (ASD), but also to milder expressions of the disorder that are below threshold for a clinical diagnosis (Bailey et al 1998; Szatmari et al 2000). Behaviors and traits that are conceptually similar to the core autism symptom domains but are not associated with disability or diagnosis (e.g., mild social or communication impairments) have been referred to as the “broader autism phenotype” (Piven et al 1997; Wassink et al 2004), and the prevalence of the broader autism phenotype in siblings of children with ASD (Sibs-ASD) has been reported to be as high as 40% (Losh et al 2008). …”

Broad Autism Phenotypic Traits and the Relationship to Sexual Orientation and Sexual Behavior

“…Higher levels of the BAP were first studied in family members of ASD individuals and were found to be highly heritable (Bailey et al 1998;Hoekstra et al 2007;Piven et al 1997a). Social and communication difficulties (e.g., having no friends, being awkward or aloof, having inadequate verbal expression, or otherwise odd verbal interactions) have been found in both parents and siblings of those with ASD (Bailey et al 1998).…”

“…Family members of those with ASD have also been found to have decreased expressive and receptive language (Piven and Palmer 1997), as well as increased difficulty using words to describe their feelings (Szatmari et al 2008). Piven et al (1997a) found that, when compared to parents of multiple children with Down's syndrome, parents of multiple children with autism were more likely to have aloof personalities and pragmatic conversation difficulties (corresponding to the diagnostic criteria related to deficits in social and communication), as well as rigidity in behavior (corresponding to the restricted, repetitive interests and behaviors diagnostic criteria; Piven et al 1997b). Bailey et al (1998) proposed that these sub-threshold characteristics in family members of those with ASD were phenotypically similar to the characteristics of ASD and labeled these traits as the BAP (Bailey et al 1998).…”