Call the Midwife: What is sickle cell disease?

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Here's what you need to know about the hereditary disease and its effects:

What is sickle-cell disease?

Sickle cell disease is a group of blood disorders, the most common (and the most serious) of which is sickle cell anaemia. Sufferers have an abnormality in the oxygen-carrying protein, haemoglobin, which is found in red blood cells.

This abnormality can have devastating effects. Health problems can include attacks of excruciating pain (called "sickle cell crisis"), anaemia (with symptoms including fatigue, dizziness, rapid heartbeat and shortness of breath), swelling in the hands and feet, bacterial infections, and even strokes – especially in children.

The disease is caused by a faulty gene passed on from parent to child and is not contagious.

To be born with sickle cell disease, a child has to inherit a copy of the faulty sickle cell gene from both of their parents. But the parent may not even be aware of the risk because it is possible to be a "carrier" and pass on the disease without suffering from the condition yourself.

If both parents carry the faulty gene, there is a one in four chance that their child will be born with sickle cell disease.

Sickle cell disease typically begins to develop when babies are around five or six months old, and pain can worsen as people get older.

Who does sickle cell disease affect?

In the UK, the NHS says that it is particularly common in people with an African or Caribbean family background. There are approximately 15,000 people with sickle cell disease in the UK.

Sickle cell disease mainly affects people of African, Caribbean, Middle Eastern, Eastern Mediterranean and Asian origin. People with "sickle cell trait" (i.e. carriers of the disease, rather than sufferers) are actually less vulnerable to malaria, which explains the gene's prevalence in these areas.

What was the prognosis in 1964?

The condition was first formally identified in 1910, but understanding of sickle cell disease progressed very slowly over the next few decades. Treatments were also limited and this family would have had few options if they received a diagnosis in 1964.

But according to the British Journal of Haematology, from the early 1970s an increase in research funding in the UK and US "led to extensive documentation of the features of the disease and controlled trials of interventions, which have increased survival and improved the quality of life in many patients."

These days, in the UK, sickle cell disease is usually detected early in the pregnancy or soon after birth, and sufferers require life-long treatment.

To avoid experiencing a painful sickle cell crisis, patients are advised to drink plenty of fluids, avoid the cold, and steer clear of sudden temperature changes. A medication called hydroxycarbamide is used, as well as daily doses of antibiotics for the rest of patients' lives. Blood transfusions and morphine may also be necessary.

The only cure for sickle cell disease is stem cell or bone marrow transplants, but this is only carried out in extreme cases because it is so risky, especially in adults.

Even today, the condition leads to a reduced life expectancy. A 2013 study looked looking at the data between 1979 and 2005 found that the average age at death for people with sickle cell anaemia was 42 years for women and 38 years for men, although the mortality rates for children have fallen in recent decades. Those with milder forms of sickle cell disease may live longer.

This article was originally published on 20 January 2019

Call the Midwife season eight airs on Sundays at 8/7c on PBS