QTL mapping
Quantitative Trait Loci mapping
Description
The genetic heterogeneity among the ASD population is reflected in the variation in clinical expression from individual to individual.
QTL is used to increase phenotypic and genetic homogeneity of study samples. Impairments in the main deficit areas of social behevior, language, and repetitive behaviors have been observed in first- and second- degree non-affected relatives of people with Autism Spectrum Disorders, which suggests familial genetic transmission. These autism-related traits can be used to identify genes which contribute to the behavioral deficits related to autism. Using these traits to stratify affected families into groups with common characteristics for quantitative linkage analysis can be used to identify quantitative trait loci (QTL). QTL are genes of small to moderate effect that contribute to continuous variation in a phenotype and allow researchers to use behavioral traits to detect genes with small effects related to autism. In fact, the Psychiatric Genomewide Association STudies Consortium Steering Committee uses phenotypes rather than diagnoses for finding genes that present risk for complex behavioral traits. Traits that have been used to identify QTL include language related traits such as non-verbal communication or age at first word, social communication scores on the Social Responsiveness Scale (SRS). 1
Criticisms
Citations
1. Piggot, J. Neural systems approaches to the neurogenetics of autism spectrum disorders.Neuroscience. 2009 May 29 PMID 19482063
