Autism and Genetics, is Autism genetic?
Autism is a disorder that is most commonly found in children. It is characterized by an emotional separation from relationships, a hindrance in communication and an inordinate amount of rigidity. Initially, this disorder was believed to have neuropathological origin but latest research brings about the idea that autism could be genetic.
Is Autism Genetic?
Autism usually involves genetic mutation. Such mutations may be in different genes for different autistic individuals. An estimated 40,000 to 100,000 genes can play a major role in this issue. While there may be many other reasons, nearly 20% cases of autism are genetic, according to scientists. A method of identifying whether this problem is genetic is by twin studies.
In 1979, a report showed that a pair of identical twins had autism. Till the age of 4 both twins developed in an identical manner, and then one improved suddenly. The other twin remained autistic, hence proving that genes were not entirely important for development. Studies made later all proved that genetic autism was more common in monozygotic twins. Dizygotic twins and normal siblings had different results with an average concordance level of less than 10% due to dissimilar environments.
The results of a research that came out in 2013 stated that autism is caused by a deletion syndrome 22q11.2 tested in a mouse model. A reduction in generation of interneurons (nerve cells that link sensory and motor nerves) or their inability to move into the cortex to control cortical circuit activity is a suggested cause for autism. The reason behind this is that the mechanisms that produce these cells have been disturbed due to mutation.
A recent article in Forbes magazine stated that an alteration in genome sequence is analogous to removal or addition of a link in a chain. The consequence of such a considerable change is that the numbers of copies made of that sequence are also altered. This variability is known as CNV (copy number variation). CNV is also described as the changing of genetic material during meiosis (division of a cell) resulting in a deletion or duplication of the material. People in a general population all carry such variants but in a negligible amount, hence when a considerable amount of variants unite, the new individual becomes a subject to autism.
Autism was first studied by a child psychiatrist by the name of Leo Kanner who distinguished it from retardation on this basis of the isolation factor of the children. A year later it was entitled by the name of ‘autistic psycopathy’. Both scientists gave the logic that this disorder was neurolopathological but in the 1950s another reason came about as to why autism may be genetic and not neurological. It was because the children who were autistic were bright, even though not very communicative and held no history of trauma at birth.
Recent research proves that genetic factors are the most significant etiology for autism since there are many reposts of abnormalities due to complex inheritance patterns.