Not too long ago, we posted an article that presented everything there was to know about the lack of correlation between vaccination and autism. The story began 20 years ago and never seemed to end, but instead, it eventually found its epilogue. Meanwhile, researchers have not stopped and have since, investigated other causes.
One of Science4life’s collaborators, Dr. Patrizia Zavattari, has been active for years in the field of research into the genetic causes of autism (or rather, Autism Spectrum Disorder or ASD); she will tell us about it in this article.
Dr. Zavattari, when did you become interested in the genetic causes of autism?
I’ve been working with it for several years, and the results that I’ve recently published are derived from a study that started in 2010 — and that were presented for the first time at the European Congress of Human Genetics in 2015. In February of this year, developments in my research group’s studies culminated in the publication in a major international scientific journal: the Journal of Clinical Medicine.
What have you discovered?
First of all, it must be said that a great number of genes have been identified; more than 800 genes and loci, which form the predisposition to Autism Spectrum Disorder. However, the contribution of each gene to the risk of developing ASD is very low, and it is therefore very difficult to say which of these genetic alterations is definitively responsible for the pathology. However, an important element is that many of these genes are involved in synaptic function.
Please explain to us what “synaptic function” is.
It’s a function that allows for the transmission of information between neurons and between neurons and other cells, such as muscle, sensory and other cells. It’s therefore a very important function for neurological development, and it’s not surprising that genes that are involved in synaptic function — especially those that allow transmission between neurons — if they’re altered, predispose the person to ASD.
How is it possible to identify the gene (or genes) most responsible for ASD among so many study subjects?
It’s very difficult, but the study of specific populations can help us. For example, the study of the Sardinian population has often made great contributions because the populations living on an island tend to be more similar to each other in their genetic make-up, and therefore recurrent genetic traits can be found more easily. Of course, now for work or study reasons, it’s very easy for Sardinians to emigrate and marry people from other regions; but there are still many people, especially in rural areas, who have lived in the same place for many generations and have often married people from neighboring countries. Therefore, by studying some Sardinian families in which unfortunately there was more than one child affected with ASD, we were able to identify a mutation including the CAPG (Macrophage-Capping Protein Gene). This gene is involved in the synaptic function we mentioned previously, and therefore is among those 800 genes that contribute toward the risk of ASD manifestation.
Can you therefore say that you’ve found the fundamental gene?
Not exactly, unfortunately. But CAPG has been shown by our studies to be one of the protagonists of the ASD story, because both when it presents the mutation and in other forms not mutated, but in which the level of CAPG is low, autism is found.
What are the advantages of knowing that CAPG is associated with autism?
The greatest advantage is to be able to make an early diagnosis of ASD in patients with CAPG deficiency and to give these families the opportunity to support the treatment path for the benefit of the child — and as early as possible. There’s still a long way to go, and that’s why we intend to carry out large-scale screening, in order to have more robust statistical data and to be able to identify the causes of CAPG alterations not resulting from gene mutation.
I’d like to conclude by saying that Italian research, despite the general economic difficulties in which it finds itself, produces excellent results and, as in this case, helps to shed light on a pathology that has proven very difficult to study.
This post is also available in: Italiano