Генетика на аутизмот

Abstract

Autism is a complex, behaviorally defined, static disorder of the immature brain. Autism is not a disease but a syndrome with multiple nongenetic and genetic causes. Autism is a wide spectrum of developmental disorders characterized by impairments in 3 behavioral domains: 1) social interaction; 2) language, communication, and imaginative play; and 3) range of interests and activities. There is convincing evidence that idiopathic autism is a heritable disorder. The recurrence rate in siblings of affected children is 3% to 6%, much higher than the prevalence rate in general population but much lower than in single-gene diseases. There are 3 main approaches to identifying genetic loci, chromosomal regions likely to contain relevant genes: 1 ) whole genome screens, searching for linkage of autism to shared genetic markers in populations of multiplex families; 2) cytogenetic studies that may guide molecular studies by pointing to relevant inherited or de novo chromosomal abnormalities in affected individuals and their families; and 3) evaluation of candidate genes known to affect brain development. Data from whole-genome screens in multiplex families suggest interactions of at least 10 genes in the causation of autism. A putative speech and language region at 7q31-q33 seems most strongly linked to autism. Cytogenetic abnormalities at the 15qll- ql3 locus are fairly frequent in people with autism. Parents need to understand that they and their affected children are the only available sources for identifying and studying the genes responsible for autism. Future clinically useful insights and potential medications depend on identifying these genes and elucidating the influences of their products on brain development and physiology.