Over the course of human evolution, various diseases and illnesses have been successfully combated. Yet, even today, with all technological advancements, some diseases are new to our knowledge. These are categorised as rare diseases.
"According to the World Health Organization’s (WHO)" a rare disease is a lifelong disease that occurs to a person or less for every 1000 persons. Most of the developed countries have their definitions of rare diseases. India is yet to define what is a rare disease.
But irrespective of all different definitions, a rare disease has very low prevalence and has no proven diagnosis or treatment.
Globally, around 6000 – 8000 diseases are categorised as rare diseases. Many more diseases are being added to this bucket regularly. However, a small bunch of around 350 rare diseases is responsible for its occurrence in 80% of people.
What causes rare diseases?
The exact reasons are still unknown for the occurrence of rare diseases. However, most genetic disorders result in rare diseases. But not all rare diseases are caused by genetic disorders.
Many rare diseases are caused by rare infections, rare autoimmune disorders, etc. Even rare forms of cancer are prevalent.
One of the common causes of rare diseases can be linked to the mutation of genes. Since genetic information tends to pass through the generations, some of the rare diseases caused by genetic mutations can be hereditary.
Some other causes of rare diseases include environmental factors, exposure to harmful chemicals, smoking, diet pattern, etc. With an increase in pollution and degradation of our surrounding environment, the risk of rare diseases may go up.
What are the characteristics of rare diseases?
- More than half of the rare diseases occur in children
- Many rare diseases are life-threatening ones
- The diagnosis and treatment are very rare for such diseases
- The bulk of rare diseases are fatal, especially among children
- Most of the cases, there will not be any trained specialists for rare diseases
- Most of them will prevail lifelong
What are some rare diseases that have a high prevalence?
A rare disease has a low prevalence in people. Paradoxically, the following rare diseases are highly common among people. It means, among all rare diseases, these are the common ones.
- Multiple Sclerosis
Multiple Sclerosis is an autoimmune disease affecting the central nervous system by inhibiting the normal functioning of the brain and spinal cord. It causes numbness in one or both limbs and eventually develops to a complex stage. Over time, it permanently damages the nervous system.
The same factors causing the disease are still unknown, but it is believed that genetic mutations and environmental factors are responsible for this disease. It is observed that low exposure to sunlight can trigger this disease in some people.
Presently, there is no proven cure for this disease.
- Narcolepsy
It is a rare condition that has a prevalence of about 50 / 1,00,000 people. It is a sleeping disorder that affects your ability to stay awake even during the daytime. It causes excessive sleepiness, sleep paralysis, muscle control, and hallucinations.
There is no success in figuring out the exact cause of this disease. Neither it has any proven treatments. But neurologists would suggest you adopt specific lifestyle changes, avoiding tobacco and alcohol, etc., to manage this disorder.
- Fabry disease
This rare condition is caused by genetic mutations and is often hereditary. It inhibits your body’s ability to produce a type of enzyme called alpha-galactosidase A, which is responsible for breaking down fatty acids. But this function gets inhibited, thus causing build-up in blood vessels and affecting various parts of your body, including the kidney, heart and brain.
It doesn’t have only one set of symptoms, but they vary based on the severity of the disease and the area where it affects. The symptoms may include hearing loss, cloudy vision, painful rashes in the skin, etc.
Some of the most common treatments available are
- Enzyme replacement therapy (ERT)
- By intaking a drug called Migalastat
The prevalence of this disease is about 30 / 1,00,000 in the population.
- Primary biliary cholangitis
It is also an autoimmune disease that affects the liver. It gradually destroys the bile ducts. Bile ducts are responsible for regulating cholesterol levels and filtering out the toxins in the body. It aids the digestion process.
When it gets destroyed, it causes severe repercussions, especially to your liver. The exact cause of this disease is highly unknown. Usually, people with this disease tend to develop symptoms only after some long years. No proven cure for this disease is studied.
Is there any governmental support?
In India, the government initiated a national policy for rare diseases. The main objective is to build awareness and necessary infrastructure concerning rare diseases.
Under the National Policy for Rare Diseases 2021, you can become eligible to receive monetary benefits from the government if you develop any pre-listed rare diseases. Do check out this policy for information like your eligibility and so on.
A word of concern
A rare disease is a lifelong phenomenon. Living with a rare disease or taking care of your loved ones affected by a rare disease requires a lot of effort.
Although there is no solid cure for most rare diseases, you try to prevent their occurrence by choosing a healthy lifestyle and avoiding being in a polluted environment.
However, you should visit your doctor as soon as possible in case of any symptoms. Because most of the time, early treatment can become an effective treatment.
