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Asperger's syndrome: Difference between revisions
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The complementary imprinted brain theory puts psychotic spectrum disorders (such as schizophrenia) on the opposite end of a spectrum from ASD, purportedly resulting from a conflict in the genomic imprinting between paternal and maternal genes, with extreme genomic imprinting in favor of paternal genes being associated with ASD.<ref>https://www.psychologytoday.com/intl/blog/the-imprinted-brain/201506/testing-the-extreme-female-brain-theory-psychosis</ref> This also corresponds with sex differences in empathizing vs systematizing<ref>https://www.pnas.org/content/115/48/12152?fbclid=IwAR0ngaYIo88A77EKpALefnsr54ZZpPWGbatCYNPBcC84HgcDGmsZ2c6VgB4</ref> which find females are generally higher in empathizing and males highest in systematizing. Autistic individuals of both sexes typically display a more masculinized behavioral phenotype in terms of systematizing/empathizing. These developmental theories are not necessarily mutually exclusive with the theories of ASD that attribute the etiology of the disorder to greater [[mutation|mutational load]].<ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5895441/</ref> | The complementary imprinted brain theory puts psychotic spectrum disorders (such as schizophrenia) on the opposite end of a spectrum from ASD, purportedly resulting from a conflict in the genomic imprinting between paternal and maternal genes, with extreme genomic imprinting in favor of paternal genes being associated with ASD.<ref>https://www.psychologytoday.com/intl/blog/the-imprinted-brain/201506/testing-the-extreme-female-brain-theory-psychosis</ref> This also corresponds with sex differences in empathizing vs systematizing<ref>https://www.pnas.org/content/115/48/12152?fbclid=IwAR0ngaYIo88A77EKpALefnsr54ZZpPWGbatCYNPBcC84HgcDGmsZ2c6VgB4</ref> which find females are generally higher in empathizing and males highest in systematizing. Autistic individuals of both sexes typically display a more masculinized behavioral phenotype in terms of systematizing/empathizing. These developmental theories are not necessarily mutually exclusive with the theories of ASD that attribute the etiology of the disorder to greater [[mutation|mutational load]].<ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5895441/</ref> | ||
==Advanced parental age and mutational load== | ==Advanced parental age and mutational load== | ||
There is some evidence that increasing deleterious [[ | There is some evidence that increasing deleterious [[mutational load]] in the population, mediated by advanced paternal age and also possibly by reductions in natural selection due to industrialization and modern medicine, is contributing to the increase in global autism diagnoses.<ref>https://www.who.int/news-room/fact-sheets/detail/autism-spectrum-disorders</ref> This secular increase in autism diagnoses is likely not be entirely explicable by the broadening of the diagnostic criteria of autism or increased awareness of the issue. | ||
Iossifov et al. (2015) found that 30% of cases of autism in simplex families (where only one immediate family member has the condition) arises from ''de novo" (novel) mutations, often transmitted from the mother.<ref>https://www.ncbi.nlm.nih.gov/pubmed/26401017/</ref><ref>https://www.simonsfoundation.org/2015/07/27/autism-risk-genes-success-with-the-simplex-approach/</ref> Taylor et al. found that simplex cases of autism were typically more problematic as compared to multiplex cases (multiple family members affected).<ref>https://www.sciencedirect.com/science/article/abs/pii/S1750946714002943</ref> Advanced parental age at birth also heightens the risk of ASD in offspring, with a possible mediating role of greater paternal age heightening the incidence of ''de novo" mutations leading to ASD in offspring.<ref>https://www.sciencedirect.com/science/article/abs/pii/S0890856719301261</ref> | Iossifov et al. (2015) found that 30% of cases of autism in simplex families (where only one immediate family member has the condition) arises from ''de novo" (novel) mutations, often transmitted from the mother.<ref>https://www.ncbi.nlm.nih.gov/pubmed/26401017/</ref><ref>https://www.simonsfoundation.org/2015/07/27/autism-risk-genes-success-with-the-simplex-approach/</ref> Taylor et al. found that simplex cases of autism were typically more problematic as compared to multiplex cases (multiple family members affected).<ref>https://www.sciencedirect.com/science/article/abs/pii/S1750946714002943</ref> Advanced parental age at birth also heightens the risk of ASD in offspring, with a possible mediating role of greater paternal age heightening the incidence of ''de novo" mutations leading to ASD in offspring.<ref>https://www.sciencedirect.com/science/article/abs/pii/S0890856719301261</ref> | ||