Sickle Cell Genotype (AA, AS, SS)

Sickle cell disease is an inherited blood disorder where red blood cells become misshapen (sickle-shaped) and break down, causing pain, organ damage, and reduced oxygen delivery throughout the body. It's caused by a genetic mutation in the haemoglobin gene.

Pre-marriage testing allows couples to:

• Know their genetic compatibility

• Make informed family planning decisions

• Seek genetic counselling if both are carriers

• Plan for potential medical needs

• Avoid the emotional trauma of having affected children

Most medications don't affect HPLC results for sickle cell testing. However, recent blood transfusions can temporarily alter results. Ideally, wait 6 months after a transfusion before having a sickle cell test.

Yes, this requires serious consideration and genetic counselling. There's a 25% chance each pregnancy could result in a child with sickle cell disease, which significantly impacts quality of life and lifespan.

• Sickle cell trait (AS): You carry one sickle cell gene and one normal gene. You are generally healthy but can pass the gene to your children.

• Sickle cell disease (SS): You have two sickle cell genes, causing the full disease with symptoms like pain crises, organ damage, and shortened lifespan.

Sickle cell is inherited in an autosomal recessive pattern. Both parents must carry the gene for children to have the disease:

• If both parents have sickle cell trait (AS), each child has a 25% chance of having sickle cell disease (SS)

• If one parent has SS and the other is AA, all children will have AS (trait)

• If one parent has AS and the other is AA, each child has a 50% chance of having AS

• AA: Normal haemoglobin (no sickle cell genes)

• AS: Sickle cell trait (carrier)

• SS: Sickle cell disease

• SC: Sickle-C disease (milder form)

• S-beta thalassaemia: Combination of sickle cell and thalassaemia genes

Yes, but there's significant risk. When both parents have sickle cell trait (AS):

• 25% chance of AA (completely normal)

• 50% chance of AS (sickle cell trait)

• 25% chance of SS (sickle cell disease)

Sickle cell trait (carrier status) affects approximately 1 in 10 (around 10%) of people of African or Caribbean descent in the UK. Sickle cell disease (the severe condition where a person inherits two abnormal genes) affects approximately 1 in 300 to 1 in 400 births in these populations. The trait is also found in people of Mediterranean, Middle Eastern, and South Asian ancestry.

Because carriers usually have no symptoms, premarital or pre-conception screening is strongly recommended to understand carrier status and potential risks for future children.

People with sickle cell trait usually live normal, healthy lives. However, you can pass the gene to your children, and under extreme conditions (severe dehydration, high altitude), you may experience complications.

Currently, bone marrow transplant is the only potential cure, but it's risky and not suitable for everyone. Most treatment focusses on managing symptoms and preventing complications.

Ideally before marriage or when planning to have children. Many couples get tested during engagement or early marriage planning. If you're already pregnant, testing should be done as early as possible.

High-Performance Liquid Chromatography (HPLC) is the clinically validated reference method for haemoglobin variant identification worldwide, offering high analytical precision and the ability to detect both common and rare haemoglobin variants.

• HPLC (High-Performance Liquid Chromatography): Gold standard, most accurate, detects all variants, provides exact percentages

• Electrophoresis: Older method, less precise, may miss some variants

• Solubility tests: Only detect sickle haemoglobin, can't distinguish trait from disease

• Rapid tests: Limited scope, often require confirmation

You will get the results on the same day.

No, fasting is not required for sickle cell testing. It's a simple blood draw that can be done at any time of day.

You should seek genetic counselling to understand your options, which may include:

• Accepting the 25% risk per pregnancy

• Considering prenatal diagnosis during pregnancy

• Exploring assisted reproductive technologies

• Considering adoption

• Making informed decisions based on your values and circumstances

Yes, prenatal testing through amniocentesis or chorionic villus sampling (CVS) can detect sickle cell disease in unborn babies, typically performed between 10-20 weeks of pregnancy. Our clinic does not offer prenatal diagnostic procedures (CVS or amniocentesis); please discuss this with your GP or antenatal care team.

Be honest and educational. Explain that sickle cell trait is generally symptomless in everyday life, but is important genetic information for family planning and rare extreme physiological conditions. Encourage relatives to get tested, especially if they are planning families.

• Inform family members who may also be carriers

• Ensure your partner gets tested

• Seek genetic counselling if planning children

• Stay hydrated during physical activity

• Inform healthcare providers of your status

Yes, people with sickle cell trait typically live completely normal lives. The main consideration is family planning and ensuring your partner knows your status before having children.