Parkinson’s disease is characterised as a neurodegenerative disease that consists mainly of the progressive loss of dopamine-containing neurons located in the substantia nigra pars compacta.
This loss results in a lack of coordinated activity, manifested by tremor, rigidity, bradykinesia (slow-motion movements) and postural instability. It also has non-motor symptoms, which can emerge up to a decade earlier. One of the problems is that by the time symptoms emerge, 60-70% of the neurons in the substantia nigra pars compacta have already gone to the graveyard.
As the disease progresses, other regions of the central and peripheral nervous system are affected with neuronal death. The enteric nervous system, which we might call “the brain of the digestive tract“, is one of the structures that are affected first, showing symptoms before muscle symptoms emerge. Some models of the disease argue that it arises in this region, and from there reaches the brain.
Parkinson’s is, after Alzheimer’s disease, the most common neurodegenerative disease and it is estimated that, as a result of high life expectancy in developed countries, its prevalence will double in the next 25 years. It is currently present in 1% of the world’s population over the age of 65. It is a disorder that is characterised by being chronic and progressive, i.e. the symptoms continue over time and worsen.
What causes Parkinson’s disease?
The causes of Parkinson’s disease are still unknown. However, some risk factors have been identified that may increase the chances of developing Parkinson’s disease.
Age and gender
Age is the main risk factor, with only 10% of patients under the age of 45. And men have been found to be much more at risk than women for developing the disease. There is evidence of a protective effect of female hormones, as well as sex-related differences in gene expression and greater male exposure to environmental risk factors.
Genetic susceptibility is another important factor. A large number of genes have been identified as possible triggers for Parkinson’s, and mutations in up to 20 Parkinson’s-related genes have so far been described.
Environmental factors also influence the development of Parkinson’s, these include:
- Environmental toxins: chemical, physical or biological substances present in the environment have a negative impact on the health of living beings.
- Pesticide exposure: misuse of pesticides, consumption of treated food and inhalation of contaminated air pose a high risk to health and the environment.
- Repeated brain trauma: repeated blows, impacts or head shaking can cause traumatic brain injury.
Presence of vascular risk factors: high blood pressure, diabetes, obesity, smoking and sedentary lifestyle are among the characteristics to be taken into account when talking about the health of the cardiovascular system.
- Exposure to certain drugs: there is scientific evidence that certain drugs induce disease. For example, contraceptives, antidepressants, smoking cessation, sedatives, antipsychotics, immunosuppressants, antihypertensives, among many others.
- The exercise of certain trades or professions: social scientists, carpenters, librarians, farmers and horticulturists, welders, gas station workers, machine drivers and carpenters are occupations associated with a higher incidence of Parkinson’s disease. Meanwhile, people working in administration and management, healthcare, repairers and electricians have a lower risk of Parkinson’s disease.
Therapies for Parkinson’s disease
There is no cure for Parkinson’s disease yet, but there are several therapies that help to greatly improve the symptoms, so it is very important to start treating it as soon as possible. Knowing the genetic predisposition to develop Parkinson’s disease we can be more attentive to the possible symptoms that develop, as well as control those environmental factors that favour it.
The most commonly used treatment is the administration of levodopa. It is a metabolic precursor of dopamine, and its purpose is precisely to compensate for the loss of dopamine caused by the death of dopaminergic neurons. Why not use dopamine directly then? Because dopamine cannot cross the blood-brain barrier, a special barrier that separates the brain from the blood, but levodopa can. All thought out. It is usually given together with carbidopa.
Parkinson’s and genetics
If Parkinson’s disease were hereditary, we would say that it is a monogenic disease, but this is not the case, as it is a complex multifactorial disease involving several genes combined with environmental factors. As genes are involved in the development of the disease, we could say that Parkinson’s is a genetically based disease. Approximately 5-10% of Parkinson’s cases have a genetic basis, with the disease appearing at an earlier age compared to non-genetic cases. In addition, as mentioned above, there are many genetic factors that increase the risk of Parkinson’s disease.
Knowing your genetic predisposition to Parkinson’s disease through a DNA test is very important, as it allows the multidisciplinary medical team to understand the disease and establish the most specific treatment possible for each patient.
With tellmeGen’s Advanced DNA kit you can find out your genetic susceptibility to develop Parkinson’s disease. This allows for possible prevention, personalised care and genetic counselling for the patient and their relatives.