The "autism genes" have been found to have useful properties
Autism genes make you smarter
Alexandra Bruter, <url>Mutations that cause autism increase the cognitive abilities of their non-autistic carriers.
This is the conclusion reached by Scottish scientists. The results of their study are published in the journal Molecular Psychiatry, published by Nature Publishing Group (Clarke et al., Common polygenic risk for autism spectrum disorder (ASD) is associated with cognitive ability in the general population).
About some congenital diseases, it has long been known in detail how they are inherited. The simpler the inheritance mechanism, the easier it is to establish the genetic nature of the disease. This is especially easy in cases with monogenic diseases caused by mutations with 100% penetrance. The words of Latin origin from the previous sentence actually mean that mutations in a single gene are enough for the development of the disease, and that the mutation, if there is one, will inevitably cause the disease. For many hereditary diseases, this is indeed the case. For example, for hemophilia, cystic fibrosis, phenylketonuria, etc.
There are much more, however, diseases for which this is not true. As a rule, these are cases of so-called "hereditary predisposition". These include, for example, a predisposition to cancer. Depending on the specific mutation in the BRCA genes, the probability of an individual carrier getting breast cancer can range from the average in the population to close to one. In this case, if the mother did not get sick, but passed the mutation to her daughter, the daughter will have exactly the same increased probability of getting sick. Oncological diseases, as a rule, develop in people in adulthood, and their probability is determined not only by heredity, but also by lifestyle.
An even more confusing picture is observed in cognitive disorders and mental illnesses. Many of them manifest themselves in early childhood and have no apparent cause.
Autism is especially "lucky" in this sense. The assumption about the connection between vaccination and the development of autism, which was not confirmed later, but was loudly and actively discussed, caused noticeable damage to the vaccination institute, and caused several epidemics of measles and mumps (mumps) in the UK and the USA. This is largely due to the fact that a child who developed normally without much stress and surprises suddenly begins to show symptoms of autism at the age of 2-3 years. During this period, there are quite a lot of vaccinations, and parents are trying to find at least some understandable reason.
But the causes of autism and other mental illnesses are of interest not only to parents, but also to scientists, and government agencies that give money for research, and private sponsors of scientific research. In recent years, quite a lot has been done in the direction of searching for the hereditary component of autism. A lot of candidate genes and their various mutations have been discovered, but the whole picture does not add up yet.
In such cases, "twin studies" are sometimes resorted to. By themselves, they cannot point to the right gene, but they can confirm or refute the assumption about the genetic causes of the disease. The essence of such studies is that by studying genetically identical homozygous (identical) twins, scientists find out whether both twins have a feature of interest or only one. If it turns out that both twins have a trait, the idea of the genetic background of this trait is indirectly confirmed. Such comparisons are especially reliable if the twins were not brought up together, but this is rare. Of all mental disorders, autism has the highest correlation between the presence of the disorder and homozygosity. But only 17% of sick twins managed to find the mutation responsible for what is happening.
Earlier we wrote that if the mutation was exceptionally harmful, due to sexual reproduction, it would most likely have been excluded from the gene pool of the species long ago ("Dual-use mutations"). And, if the mutation exists and, moreover, is spreading more widely (and it seems that with all the overdiagnosis, the incidence of autism is growing), it's time to ask the question: "Si prodest"? To whom and how does it make life easier?
Scottish scientists have found the answer to this question (the press release of Autism genes and intelligence link found is published on the website of the University of Edinburgh – VM). It turned out that non-autistic carriers of already known mutations associated with the development of autism have more outstanding cognitive abilities, especially in non-verbal areas. It has already been noticed before that children with autism sometimes have good abilities in some, mostly abstract, areas, for example, in mathematics (for example, like the hero of Mark Haddon's novel "The Mysterious Night Murder of a Dog"), but in general, the intelligence of such children is still reduced. In people with a less severe autism spectrum disorder – Asperger's syndrome – this effect is even more noticeable. Their intelligence, as a rule, is not reduced, and with noticeable difficulties in the field of social, they can achieve significant intellectual success.
If the concept of Scottish scientists is correct, it explains the increase in the incidence of autism. Sexual selection in developed countries has increasingly favored the "smart" rather than the "sociable" as before. IT, for example, is one of the most highly paid and least stressful areas of wage labor, and even does not require communication skills from most employees. At the same time, the social status of IT workers is quite high and continues to grow. Most often they have a very prosperous financial situation. A high social status, a stable income and a normalized working day greatly help a modern person to pass on their genes to offspring. And if the same mutation improves cognitive abilities in some, and causes autism in others, it will spread in modern society.
Portal "Eternal youth" http://vechnayamolodost.ru11.03.2015