Catalina Betancur, Etiological heterogeneity in autism spectrum disorders: More than 100 genetic and genomic disorders and still counting, Brain Research 1380 (2011) 42-77
There is increasing evidence that autism spectrum disorders(ASDs) can arise from rare highly penetrant mutations and genomic imbalances.
The data provide strong support for high-resolution DNA microarrays as well as whole-exome and whole-genome sequencing as critical approaches for identifying the genetic causes of ASDs.
Over 70% of individuals with autism have intellectual disability (ID), while epilepsy occurs in ~25%.
The findings indicate that, in contrast to a persisting claim that we know very little about the etiology of autism, there are more than 100, already identified, recurrent genetic defects than can cause ASD. All the genes and chromosomal rearrangements identified are well-known cause of ID, either syndromic or non-syndromic. Several have been involved in epilepsy, with or without ID, suggesting that this is another neurodevelopment disorder that shares genetic risk factors with ASD.
There is every reason to believe that with whole-exome and whole-genome sequencing approaches mutations in these genes will be identified in additional cases, and many more ASD loci will be discovered.
The data presented in this review makes in abundantly clear that autism represents the final common pathway for numerous genetic brain disorders.