Research in the field of genetics has made great strides in recent times.

While our knowledge of genetics and how it works can still be greatly improved, the knowledge it provides has enabled great advances to be made. Science has allowed progress in the treatment of different diseases and disorders by locating the elements of DNA that cause or facilitate them and allowing the creation of medicines and treatments more suitable to cure or alleviate their effects, or to avoid transmitting them to offspring.

Examples include the treatment of various genetic disorders and the prevention of diseases with a high probability of occurrence (such as some cases of breast cancer). However, genetics does not allow an exact prediction of the occurrence of the phenomena, affecting the expression of genes by the life history of individuals. In the case of some disorders such as mental disorders, the exploration of the genome still has a long way to go, there is still no exact knowledge of which genes predispose to suffer from them, but it is known that in some cases there is a predisposition due to genetic influence. This is the case of anxiety disorders.

What is anxiety?

The concept of anxiety refers to a diffuse emotional state similar to fear, in which the advent of a future threat is expected. This fear is disproportionate, irrational and induces avoidance or desire to avoid feared or fear-like situations.

The category of anxiety disorders includes various disorders, such as generalized anxiety disorder, phobias, and anxiety disorder with or without agoraphobia. In the past, obsessive-compulsive disorder was also considered as part of this category due to the fact that subjects with this disorder present a very high level of anxiety and their symptoms are derived from a particular management of anxiety, although its differential characteristics make it have been separated from this group in the latest version of the American classification of mental disorders par excellence (DSM-V).

Anxiety disorders are the most common type of mental disorder in both clinical and non-clinical populations. The presence of vital trauma in early childhood is a risk factor for their condition. Likewise, a certain genetic predisposition has been found in some subjects to suffer from it , a predisposition that has contributed to promoting research into genes that may explain this relationship.

Seven genes recently linked to anxiety

Recent research has attempted to find a link between some genes and the existence of anxiety disorders or anxiety related symptoms.

In this sense, it must be taken into account that even if we are talking about specific genes, the presence or absence of genetic predisposition does not depend on a single gene, but it is considered to be polygenic. In other words, a gene does not mark a characteristic by itself, but this characteristic depends on the joint action of various genes and how they are configured in the set of chromosomes.

1. Gen Mmp9 (Matrix metallopeptidase 9)

In this gene, four haplotypes or mutations and different combinations of specific alleles have been analysed and found to be linked to anxiety. According to previous studies this gene is involved in coronary disorders and cancer, which correlates positively to both anxiety as a predisposing element and to suffering anxiety as a result of knowledge of the disease.

2. Bdnf (Brain-derived neurotrophic factor) gene

Only one haplotype of this gene, AGAT, presents a good and high association with the predisposition to anxiety disorders . This gene contributes to cell maintenance, allowing the modification of the synaptic space between neurons through the secretion of neurotrophins. It has also been associated with brain plasticity. It has been related to the neurotransmitter serotonin, which also affects the proliferation of neurons.

3. Ntf4 (Neurotrophin 4) gene

This gene is involved in the modulation of synaptic space. It is essential for the survival and maintenance of neurons, especially those in the striatum. More research is needed regarding its involvement in anxiety disorders, but studies seem to indicate that it is involved in vulnerability to these disorders , especially if it occurs in conjunction with the previous one

4. Genes Egr2 and Egr4 (Early-Growtg Response 2 & 4)

These genes are involved in synaptic plasticity, especially in learning and memory . They are also involved in bone formation in the skull and myelinization of the peripheral nervous system.

5. Grm2 gene (Glutamate receptor 2)

This gene participates, as you can imagine from its name, in the reception and metabolism of glutamate , the major exciter of the central nervous system. This link with glutamate makes this gene a very important element in anxiety disorders and even schizophrenia. In addition to anxiety disorders, it is linked to learning.

6. Gen Arc (Activity-regulated cytoeskeleton-associated protein)

This gene is known and studied for its link with neuronal plasticity and the genesis of proteins that allow it . It participates and acts on NMDA receptors.

Look out! Caution with biological determinism

The discovery of these genes and their relationship to anxiety related mental disorders is a major milestone in contributing to the study and treatment of anxiety disorders. However, it must be taken into account that the presence of certain genetic configurations only implies an innate predisposition to express the phenotypes to characteristics to which they predispose.

Considering that possessing these genes means suffering from an anxiety disorder would result in a fallacy , since it can make us forget the modelling influence of the environment and education, elements that can awaken or ignore biological predisposition. Anxiety disorders, like all other psychological disorders, have a plural and biopsychosocial etiology.

Care must be taken not to fall into reductionism and to consider the effect of all the variables that may have an implication on the disorders, both anxiety and other types.

Bibliographic references:

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