Proposed Models
Twin and family studies show that autism is a highly heritable condition, but they have left many questions for researchers, most notably
- Why is fraternal twin concordance so low considering that identical twin concordance is high?
- Why are parents of autistic children typically non-autistic?
- Which factors could be involved in the failure to find a 100% concordance in identical twins?
- Is profound mental retardation a characteristic of the genotype or something totally independent?
Some researchers have speculated that what we currently refer to as "autism" may be a catch-all description for many yet unknown conditions with different genetic and/or environmental etiologies. This would appear to make the effort to find a genotype model a lot more difficult, and perhaps even pointless. Nevertheless, a number of genetic models have been proposed to try to explain the results of twin and sibling studies.
Read more about this topic: Heritability Of Autism
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