Genetic Influences and Autism

Brief Report: Autism in Individuals with Down Syndrome

“…Claims have been made in the past, particularly with respect to the fragile X anomaly, that either the chromosomal mutation caused a specific liability to autism or that its location meant that it had effects on a susceptibility gene for autism that was located very close to it (Gillberg & Wa¨hlstrom, 1985). With the probable exception of a chromosome 15 mutation (Folstein, & Rosen-Sheidley, 2001), such effects seem unlikely (see Rutter, 2005). There are case reports of autism in individuals with mutations on almost all chromosomes (Gillberg, 1998), but the associations with autism are almost certainly very weak in most cases.…”

Progress in Understanding Autism: 2007–2010

“…Twin and family studies undertaken over a period of several decades have been consistent in showing that ASDs have an overall heritability of about 90% (Rutter 2005b). The falloff rate from MZ to DZ twins, together with that from first degree to second degree relatives, was used by Pickles et al (1995) to estimate the number of genes that were likely to be involved (Pickles et al 2000).…”

Screening for Autistic Spectrum Disorder in Children Aged 14–15 Months. II: Population Screening with the Early Screening of Autistic Traits Questionnaire (ESAT). Design and General Findings

“…Secondly, parents might want to know the diagnosis because of the genetic risks when considering having another child. It is of note that the siblings of a child with autism have themselves an increased risk of about 3-7% of developing ASD (Rutter, Bailey, Simonoff, & Pickles, 1997). Thirdly, some evidence exists for the benefits of early intervention in terms of IQ gains, language gains, improved social behavior, and reduction in symptom severity (Howlin, 1997;Rogers, 1996).…”