To explain the relationship between fibromyalgia and genetics, we must first answer another question: what is fibromyalgia? Fibromyalgia is a chronic pathology (which means it is long-lasting) whose main characteristic is musculoskeletal pain throughout the body.
Symptoms beyond pain
Although it is the most dominant characteristic, it is not the only one. It is accompanied by constant fatigue, regardless of how much one has slept, hypersensitivity and an alteration of cognition, such as memory and mood problems.
Sleep problems are largely related to the pain itself, which wakes the patient up. It is common for other sleep disorders such as apnoea and restless legs to arise. It is a complex disease which is still being actively researched.
Why is fibromyalgia so difficult to diagnose?
From a diagnostic point of view, it is complicated. Although it causes pain in multiple areas of the body, mostly soft tissues, it leaves no clues or organic evidence to link it. Unlike other diseases, there is no inflammation or visible marks.
Telling the doctor that you have fatigue and pain does not narrow down the list of problems you may be suffering from too much, so diagnosing it usually requires a lot of time and visiting several professionals. It is discovered, not by performing a direct detection (a single test is not yet available), but by ruling out those similar diseases until only fibromyalgia remains. Therefore, there are no specific tests.
The exact causes are still being studied. It is known that the main cause is central sensitisation. The central nervous system develops an exaggerated response to pain. The person’s perception of pain is altered, causing them to feel pain from sensations that should not provoke it, or more pain than an unaffected person would feel.
This hypersensitivity already mentioned also occurs with other stimuli such as temperature, electricity and even noise in some cases.
The factors that provoke it are complex. It is considered a multifactorial disease. In most cases, the person would have a genetic predisposition to the pathology, but it would be “activated” by an environmental stimulus, such as a bacterial infection or an accident.
It is observed that people with fibromyalgia may present a higher comorbidity with some psychiatric disorder. Even the psychological problem can be the trigger, such as prolonged stress.
Genetic factors of fibromyalgia
Fibromyalgia is one of those pathologies that falls into the category of genetic vulnerability, but not direct heritability. You do not inherit the disease from your parents, but a greater risk of developing it has been proven when there have been cases in close relatives.
It has been proven to be up to eight times more frequent among members of the same family.
Discovering the genes involved in such a complex disease is a challenge, but research is advancing. It is believed that there may be more than fifty genes related to the pathology, participating in different pathways such as the glutamate pathway or serotonin production.
One of the largest studies conducted, which has analysed information from 2.5 million people, including more than 50,000 people affected by the disease, has identified 26 regions of the genome linked to fibromyalgia.
No one was surprised when they checked the obtained results and saw that the majority of the genes that seemed to participate in fibromyalgia were genes that fulfilled functions within brain activity. Many are key genes in the reception and perception of sensations, such as the CAMKV, DRD2, MDGA2 and CELF4 genes.
This would explain the main symptom of the disease, perceiving light and mild pressures as a sensation of pain.
Curiously, one of the genetic variants that increases the risk of suffering the pathology has been in the Huntingtin gene, the same gene that causes Huntington’s disease. The results, furthermore, coincide with what was assumed about the disease until now: it is not direct damage to the tissues, but errors of communication within the nervous system. This reaffirms how complicated it is to diagnose and the absence of specific or evident markers.
Curious fact: fibromyalgia affects women much more than men. In one study they obtained that 9 out of 10 cases are in women. In another with patients suffering from chronic fatigue syndrome, 29% of men had fibromyalgia compared to 58% of women.
However, from the genetic point of view, women do not have a greater risk. The affected genes do not present differences in their activity due to the sex of the individual. Therefore, other factors independent of genetics such as hormones or lifestyle must be responsible for this disparate risk.
Nowadays it is another open line of research around fibromyalgia that has not yet been answered. Due to that, even the best genetic analyses such as the tellmeGen DNA test have limitations in calculating the person’s exact predisposition to develop the pathology. It must be mentioned again that just the genetic and physiological factors of the person are not sufficient. Studies agree that an environmental trigger is needed to set it in motion.
Can fibromyalgia be cured?
As with many chronic diseases, the current goal of treatment is not a cure, but comprehensive management of symptoms. However, many treatments have achieved strong symptom control.
Treatment is multidisciplinary, involving different specialists, from nutritionists (weight loss is also recommended if the person is obese) to rheumatologists and physiotherapists.
Other non-pharmacological methods include physical exercise, electrotherapy, massage, and heat application. Therapy and perhaps psychological counselling are recommended, given the strong relationship between fibromyalgia and psychiatric disorders and stress.
Analgesics are used on an ad hoc basis among pharmacological treatments. Some antidepressants and antiepileptics have had very positive results, especially in helping patients sleep. Pain in specific areas of the body can be one of the most persistent aspects, regardless of the medication used.
It is a complex disease and pain is only its most notable facet; however, it is an area of intense scientific research in which progress is being made.
