Obsessive-compulsive disorder – HTR2A and SLC6A4 genes


Obsessive-compulsive disorder (OCD), also known as anancastic neurosis, is an alteration of mental health characterized by obsessive and compulsive thoughts.

More specifically, obsessive thoughts more often include fear of disease or contamination, a desire for symmetry or doing things "right", or intrusive thoughts that involve religion, sex or aggression. On the other hand, compulsions consist of the repetitive execution of certain actions, such as checking, washing, counting, organizing, carrying out specific routines or seeking safety. These behaviors are performed to relieve anxiety, instead of seeking pleasure as in other compulsive behaviors such as play, food or sex.

People with OCD generally suffer from anxiety and other anxieties around their need to adapt to their obsessions or compulsions. Approximately half the time, OCD becomes evident in childhood or adolescence, and most other cases appear in early adulthood. Some people with OCD, have additional mental health disorders, such as generalized anxiety, depression, phobias, panic disorders or schizophrenia. OCD can also occur in people with other neurological conditions such as Tourette syndrome and other similar processes, traumatic brain injury, stroke or dementia.

The cause of the obsessive-compulsive disorder (OCD) is unknown; however, it is believed that this process could involve changes in certain neurotransmitters such as serotonin or dopamine. It is also believed that problems with the regulation of activity and the interaction between various parts of the brain contribute to the development of this process.

Some variations in certain genes that code for proteins that carry serotonin have been associated with an increased risk of OCD. These genes include the HTR2A (5-hydroxytryptamine receptor 2A) gene, located on the long arm of chromosome 13 (13q14.2) and the SLC6A4 (solute carrier family 6 member 4) gene, located on the long arm of chromosome 17 (17q11.2). Variations in other genes involved in communication in the brain may also be associated with the disease. In addition to genetic factors, it is believed that certain environmental factors may contribute to OCD, including complications during pregnancy or childbirth and stressful events in life. 

The inheritance pattern of the obsessive-compulsive disorder (OCD) is not clear. In general, the risk of developing this process is greater for first-degree relatives of affected people compared to the general population.

Tests performed in IVAMI: in IVAMI we perform the detection of mutations associated with the obsessive-compulsive disorder, by means of the complete PCR amplification of the exons of the HTR2A and SLC6A4 genes, and their subsequent sequencing.

Recommended samples: blood extracted with EDTA for separation of blood leukocytes, or card impregnated with dried blood sample (IVAMI can mail the card to deposit the blood sample).