Doctor, do rare diseases run in the family?

dr flo, genetic, rare diseases
A mother and child
Photo credit: SHUTTERSTOCK

What you need to know:

  • In some countries, tests can be done to check for rare and hidden diseases, or for the genes that predispose someone to get a specific disease.


As a mother, if I have a rare condition/disease, will my children inherit it and carry the disease to the entire lineage?

Dear Reader,

Most rare diseases are genetic, and as such, can be passed on to offspring. However, this transmission is not always automatic, depending on the disease, and in some cases, if the biological father of the child does not have the disease, then it may affect how it is transmitted.

If you have a genetic disease, it is advisable to go for genetic counselling before getting children. In some countries, tests can be done to check for rare and hidden diseases, or for the genes that predispose someone to get a specific disease.


There is someone who is over eight feet tall. Could this be a problem? How comes there are not many people who grow to that height?

Dear reader,

Height that significantly exceeds what is expected is usually due to gigantism, a rare disease. Rare diseases are diseases that affect only a small portion of the population. They may affect any of the body systems and they have different causes, though most of them are genetic.

In total, there have been about 100 people worldwide ever reported to have gigantism. With gigantism, the individual has excess production of a growth factor during childhood, which leads to being very tall, large hands and feet with thick fingers and toes, large head, hormonal changes,protruding forehead, enlarged jaw, recurrent headaches, problems with vision, excessive sweating, joint and nerve problems, and cardiovascular disease.

This excess production of the growth factor is usually due to having a pituitary tumour or pituitary enlargement, or rarely due to having a tumour elsewhere in the body that produces the growth factor. A diagnosis is made by checking the levels of the growth hormone and other growth factors, and also the levels of other hormones. Scans may be done to check for tumours in the brain or elsewhere.

Treatment includes removal of tumour, if present and operable; followed by medical treatment and radiotherapy, if necessary.

Dear doctor,

About 10 years ago when I was undergoing circumcision, it was discovered that I had a bleeding disorder, which I later came to learn is called haemophilia. Since then I have always lived in fear of getting hurt so that I do not bleed too much. Kindly enlighten about this


Dear Kevin,

Haemophilia is a genetic blood disorder where there is a deficiency of one of the factors needed to help your blood clot. The person with haemophilia will bruise easily, have prolonged bleeding even from mild injury and may have spontaneous bleeding from different sites.

Symptoms of spontaneous bleed include recurrent nose and gum bleeds, blood in stool, urine, vomit or sputum; low blood level (anaemia), low blood pressure, weakness and fainting, easy fatiguability, swollen and painful joints; headache and neck stiffness.

The diagnosis is made through blood tests that check blood cells and coagulation (clotting) studies, including looking at levels of specific clotting factors.

Treatment of each bleeding episode depends on severity and may involve stopping the bleeding, medication to help with clotting, giving the missing clotting factors through transfusion, and managing other symptoms.

Haemophilia is not curable. However, with appropriate education and treatment, someone with haemophilia can live a productive life.

Can the CBD oil (medical marijuana) be used to cure rare diseases?

Dear reader,

Most rare disease are genetic, some are infectious, some are cancers... There are over 5,000 distinct rare diseases and there can never be one cure for all.

In addition, genetic diseases cannot be cured.

However, the medical marijuana may be used to relieve symptoms like pain, nausea and loss of appetite, that are experienced by patients suffering from some rare diseases.

Send your health questions to [email protected]