Sickle Cell Disease and Trait: What Every Family Should Know

The sickling test is a diagnostic blood test used to detect sickle cell disease or sickle cell trait. It checks for the presence of abnormal Hemoglobin S, which causes red blood cells to take on a crescent or "sickle" shape under low-oxygen conditions.

In the laboratory, a chemical called sodium metabisulphite is mixed with the blood sample, which quickly identifies whether sickle cells are present. A trained technician observes the sample under a microscope and looks for deformed red blood cells.

A negative result means no Hemoglobin S was detected; the person is unlikely to be a carrier or have the disease. A positive result means HbS is present in the blood.

These two conditions share the same gene mutation, but they are not the same thing and they do not carry the same implications.

Sickle cell disease and sickle cell trait both stem from a genetic variation in the HBB gene, the gene responsible for producing hemoglobin. A person inherits two copies of this gene, one from each parent.

Sickle cell disease follows an autosomal recessive inheritance pattern. This means a child needs to receive a mutated gene from both parents to develop the disease.

If both parents carry the sickle cell trait, there is a 25% chance the child will have sickle cell disease, a 50% chance the child will carry the trait, and a 25% chance the child will have normal haemoglobin, with each pregnancy.

If one parent has sickle cell trait and the other has normal haemoglobin, their child may inherit the trait but will not develop sickle cell disease.

These are probabilities per pregnancy, not a sequence. Having one child with normal haemoglobin does not reduce the risk for the next child; each conception carries the same odds independently.

For couples planning pregnancy, genetic testing is available if one or both partners carry the trait or have the disease. For pregnant patients, prenatal testing options are also available. Genetic counselling helps families understand these risks clearly and explore their options before conception or early in pregnancy.

People with sickle cell disease start to have signs of the disease during the first year of life, usually around 5 months of age. Symptoms and complications are different for each person and can range from mild to severe.

The primary symptom of sickle cell disease is pain. Patients often experience chronic pain punctuated by vaso-occlusive crises, episodes where sickled red blood cells block blood vessels, causing ischemia and inflammation in surrounding tissues. These crises can affect the bones, joints, chest, and abdomen, and often require medical attention or hospitalisation.

Other complications include anaemia, debilitating acute and chronic pain, increased susceptibility to infection, acute chest syndrome, stroke, and progressive organ damage, including decreased cognitive function and kidney failure.

Patients with sickle cell disease may also experience fatigue and increased vulnerability to infections, particularly bacterial infections, which is why preventive care from infancy is important.

Management of sickle cell disease focuses on preventing and treating pain episodes and other complications. Treatment options and their effects can differ for each person, depending on the symptoms and severity of their disease.

Several approaches are used:

Hydroxyurea is one of the most widely prescribed medications for sickle cell disease. It works by stimulating the production of foetal haemoglobin (HbF), which does not sickle, reducing the frequency of pain crises and acute chest syndrome.

Blood transfusions help by diluting the proportion of sickled cells in circulation, reducing the risk of stroke and managing severe anaemia.

Bone marrow or stem cell transplant is currently the only established curative option, though it is not available to all patients due to the need for a well-matched donor. Gene therapies are emerging as treatment options for some patients and represent a significant advance in the field.

In children, preventive care includes vaccinations and daily low-dose penicillin, typically from infancy until at least age five, to guard against bacterial infections, which can be life-threatening in early sickle cell disease.

Early diagnosis, regular screenings, preventive interventions, and access to specialist care can meaningfully decrease illness and extend life.

A positive sickling test at a routine checkup or premarital screening can feel alarming before the confirmatory result comes back, which is exactly why moving quickly from screening to confirmation matters.

Diagnostics: 8,500+ NABL-Accredited Labs

Employees and their families can book the Sickling Test for initial screening and Hemoglobin Electrophoresis for confirmatory testing, cashlessly through Visit Health's diagnostic network. Home sample collection is available for both, and results are tracked digitally through the app for the whole family's records.

Teleconsultation: Haematology and Internal Medicine Specialists

A positive sickling result, questions about family planning risk, or a confirmed diagnosis needing a management plan all warrant a direct conversation with a specialist rather than piecing together information alone. Visit Health's teleconsultation platform connects employees with haematology and internal medicine specialists across 30-plus specialties, with general physician consultations typically available within 15 minutes and specialist consultations within 60 minutes.

AI-Powered Smart Reports

An electrophoresis report listing haemoglobin fractions like HbA, HbS, and HbF isn't always easy to interpret without medical training. Visit Health's Smart Reports translate these findings into plain-language summaries, explaining whether the result points to trait, disease, or a normal profile.

What does a sickling test positive result mean?

A positive sickling test means that Hemoglobin S, the abnormal haemoglobin associated with sickle cell, was detected in the blood sample.

Does sickle cell trait cause any symptoms?

In most cases, no. People with sickle cell trait carry one normal and one abnormal gene and typically live full, healthy lives without any symptoms of sickle cell disease. In rare circumstances.

Can sickle cell trait turn into sickle cell disease?

No. Sickle cell trait cannot become sickle cell disease. 

If both parents have sickle cell trait, what are the chances their child will have sickle cell disease?

With each pregnancy, there is a 25% chance the child will have sickle cell disease, a 50% chance the child will carry the trait, and a 25% chance the child will have completely normal haemoglobin. 

What is the difference between a sickling test and haemoglobin electrophoresis?

The sickling test is a rapid screening test that detects whether Hemoglobin S is present at all. 

At what age does sickle cell disease start showing symptoms?

Symptoms typically begin around 5 months of age, when foetal haemoglobin (which protects newborns) naturally declines and is replaced by the abnormal adult haemoglobin.

Is sickle cell disease curable?

A bone marrow or stem cell transplant is the only currently established cure, but it requires a well-matched donor and carries significant risks. It is not an option for most patients. Gene therapy is an emerging area that has shown early promise and may expand curative options in the coming years.

Know Your Sickle Cell Status.
Book a sickling test and get expert guidance with Visit Health.