Rare diseases are conditions that affect a small number of people compared to the population as a whole. A disease is considered to be rare when it affects 1 out of 2000 persons. It is also deemed to be scarce in one region but is common in another. There are thousands of rare diseases in the world. Six to seven thousand diseases are considered rare and new diseases are regularly described in medical literature. Diseases that are rare are serious, often chronic and progressive. Signs may be observed at birth or in childhood. However, over 50% of these diseases appear during adulthood.

While we have all heard of these rare diseases in the world, seen someone with a disease, and personally had a disease, it is very uncommon that we have encountered a rare disease. People use and interchange conditions to mean infection, sickness, or illness. In the medical world, a disease is an abnormal condition that impairs the function of the body and is associated with certain signs and symptoms. These kinds of diseases are also called Orphan diseases because it is very uncommon and have such low prevalence.

Here is the list of 10 rare diseases that rarely affect people.

10. Smallpox

rare diseases

Credit: diseasespictures

Smallpox is a contagious, deadly disease that has affected humans for thousands of years. It is characterized by high fever, fatigue, and a rash with flat red sores that can cover the entire body. It is believed that smallpox is one of the deadliest diseases, killing millions in the last century.

Smallpox was eradicated worldwide last 1980 because of the unprecedented global immunisation campaign. Because of this, smallpox is said to be extremely rare. Nowadays, the threat of smallpox still exists in the form of bioterrorism. Samples of smallpox have been kept for research purposes. There is no cure or treatment for this disease.

9. Polio

polio disease

Credit: diseases-blog.blogspot

Polio was first known and recognised in 1840. Polio is a disease that spreads from people to people through contaminated food or water. It’s a contagious viral illness that causes paralysis, difficulty breathing, and sometimes death. Most cases of polio show no symptoms unless the disease is introduced into the blood stream.

Despite a concerted global campaign, poliovirus continues to affect children and adults in Pakistan, Afghanistan, and other African countries. If a person was previously vaccinated and is planning to travel to an area where polio is occurring, he should have a booster dose of inactivated polio vaccine. The immunity after this booster dose lasts a lifetime.

8. Hutchinson-Gilford Progeria

rare diseases in the world

Credit: emaze

Usually known as Progeria, this disease is an extremely rare, progressive genetic disorder that causes children to age rapidly starting from their first two years of life. This condition only affects one in about 8 million children born. Children with Progeria appear normal at birth. During their first year, signs and symptoms such as slow growth and hair loss begins. Most born with the condition usually live until the age of 13 while some can live in their early twenties.

Heart problems or strokes are the eventual cause of death in children with Progeria. In most cases, the disease is not inherited though there has been a case where the parents carry the protein genetically and pass it on to their children. There is no cure for Progeria, but research shows some promise for treatment. Doctors have tried growth hormone therapy and anticancer drugs.

7. Fields Disease

uncommon diseases


Fields disease is the rarest disease in the world and is named after Catherine and Kirstie Fields, twins from Wales. The twin was born with a previously undiagnosed neuromuscular disease that affects the nerves that cause voluntary muscle movement.

The twin’s movement was limited because the muscles within the body are slowly deteriorating. The said disease has been studied by doctors all over the world. The disease is so rare and unknown, and doctors are not sure what will happen next, but the twins could pass the condition to their future offspring.

6. Fibrodysplasia ossificans progressiva (FOP)

deadly diseases

Credit: fitnessfrenzie

It is a severely disabling disorder of connective tissue that has the possibility to be passed to future generations by congenital malformations of bones. The disease is very rare and could only affect one in every 2 million people around the world. FOP is classified when the body causes fibrous tissue to become ossified, or to change into bone when damaged. Bones can grow within the muscles and tendons all over the body.

It is the only known disease that causes one type of organ system to turn into a different one. Children who have FOP appear normal at birth, but it can be noticed that there is a congenital malformation on the great toes. There is no known treatment such as surgery to get rid of the bone because it will cause the body to produce even more bones.

5. Kuru

dangerous diseases

Credit: norkinvirology.wordpress.com

Kuru is rare and fatal. It is caused by an infectious bacteria that can be found in contaminated human brain tissues. Kuru can be found in New Guinea, specifically the Fore tribe, that practised cannibalism in which they ate the brains of dead people as part of the funeral ritual. Those affected with the disease becomes unable to eat or stand and later die in a comatose state. Because of government’s effort to intervene to end cannibalism, Kuru has now mostly disappeared.

4. Von Hippel-Lindau (VHL)

deadliest diseases

Credit: www.jmgims.co.in

VHL is said to affect one in every 35,000 people. It is a very rare genetic condition that is often characterised by the growth of numerous tumours in different parts of the body. It is an inherited disorder causing benign and malignant tumours to develop in the central nervous system and viscera.

These tumours can start to grow in the retina, the brain, and in the spinal cord. Tumours also arise in the pancreas, epididymis, and the inner ear. If left untreated, this kind of disease can cause heart attacks, cardiovascular disease, or stroke. The age at which the tumours present ranges from childhood to the seventh decade of life.

3. Microcephaly

rare diseases

Microcephaly is a very rare neurological condition in which infant’s head is relatively smaller than the heads of other children of the same age and sex. Microcephaly is noticeable immediately after birth and sometimes even before. With microcephaly, the brain is unable to develop properly or ceases to grow at all while the baby is still in the womb.

Many believe that the disease is caused by the exposure to harmful substances while in the womb. Those who have microcephaly are usually mentally retarded and have issues with hyperactivity, seizures, speech, dwarfism, balance, and motor problems as well. There is no treatment for microcephaly but therapies such as speech, and occupational therapies will help enhance the child’s development and improve the quality of life.

2. Paraneoplastic Pemphigus (PNP)

Paraneoplastic PemphigusCredit: pcds.org.uk

The Pemphigus family is a rare blistering disease that affects the skin or the mucous membranes. This condition occurs in malignancies and is characterised by painful blisters and denuded areas of the mouth, lips, oesophagus, and the skin. There are many forms of Pemphigus and Paraneoplastic Pemphigus is the least common and most dangerous. The disease is fatal as 90% of those who are diagnosed with the disease die because of sepsis, multi-organ failure, or cancer.

1. Morgellons

rarest disease in the world


Morgellons disease is a mysterious, uncommon, and unexplained skin condition that is distinguished by crawling sensations, sores and fibre like filaments emerging from the wounds. It is a relatively rare condition that frequently affects middle-aged women. Morgellons stands as a poorly understood disease and is believed to be a chronic infectious. There is no known cure or treatment for Morgellons.

Facts and statistics about genetic and rare diseases

Rare and genetic diseases are uncommon to most doctors and represent a large medical challenge. Here are a few statistics and facts to illustrate the breadth of the ten rare diseases problem worldwide.

  1. There are estimated 7,000 types of rare disease and disorders.
  2. 10% of the US population is living with a rare disease.
  3. Europe has approximately 30 million people living with a rare disease and 350 million people worldwide suffer from a rare disease.
  4. If all the individuals with a rare disease tend live in the same country, it will be the third world’s most populous country.
  5. A condition is considered rare in the US if it affects less than 200,00 people combined.
  6. 80% of rare diseases are genetic and are present throughout the person’s life even if symptoms do not appear immediately.
  7. 50 % of the people affected by this disease are mostly children.
  8. 30% of children with this disease will not be able to live to see their 5th birthday.
  9. 35% of deaths in the first year of life are caused by this rare disease.
  10. The prevalence distribution of rare disease is skewed.
  11. 95% of rare diseases have no FDA-approved drug treatment.
  12. At the first 25 years of Orphan Drug Act, 326 new drugs were approved by the FDA for patients with a rare disease.
  13. Only 6% of the inquiries made to the GRDIC or Genetic and Rare Disease Information Center are an undiagnosed illness.
  14. 50% of these diseases do not have a particular foundation that supports and research about the disease.


Leave a Reply

Notify of