Sickle cell disease is a group of inherited blood disorders affecting red blood cells, which normally carry oxygen throughout the body. In this condition, a genetic change causes red blood cells to become stiff, sticky, and crescent-shaped, resembling a farm tool called a sickle. These misshapen cells can block blood flow, leading to pain, organ damage, and other health complications. Sickle cell trait, in contrast, means an individual carries one copy of the gene for sickle cell disease but typically does not experience symptoms, though they can pass the gene to their children. Testing helps identify individuals with the disease or trait, allowing for early intervention, informed reproductive decisions, and appropriate medical management.
Who Needs Testing
Newborn screening is a widespread practice in many regions, including all U.S. states, identifying sickle cell disease and trait shortly after birth for timely medical care and complication prevention. Individuals with a family history of sickle cell disease or trait are also encouraged to seek testing, as the condition is inherited.
Prospective parents or those already pregnant can benefit from screening, especially if from ethnic backgrounds with a higher trait prevalence. Prenatal screening helps couples understand their risk of having a child with sickle cell disease and consider family planning. People of African, Mediterranean, South Asian, Caribbean, and Hispanic descent have a higher incidence of sickle cell trait.
Types of Sickle Cell Tests
Testing for sickle cell disease or trait typically begins with a simple blood sample. For newborns, a few drops of blood are usually collected from a heel prick. For older children and adults, blood is drawn from a vein, commonly in the arm. These samples are then sent to a laboratory for analysis.
Common laboratory tests identify the types of hemoglobin present in the blood. Methods such as hemoglobin electrophoresis, high-performance liquid chromatography (HPLC), and isoelectric focusing (IEF) are frequently used. These techniques separate and measure different hemoglobin variants, including hemoglobin S (HbS), which is characteristic of sickle cell conditions. Genetic testing, which analyzes DNA, can provide definitive confirmation of sickle cell disease or trait by identifying specific gene mutations. This type of testing is often used to confirm initial screening results or for prenatal diagnosis.
Where to Get Tested
Accessing a sickle cell test often begins with a primary care physician or family doctor. These healthcare providers can order the necessary blood tests or provide referrals to specialized laboratories. Hospitals and clinics typically have laboratory services equipped to perform sickle cell testing.
Community health centers serve as accessible options for testing, sometimes offering services at reduced costs or as part of public health initiatives. Public health departments and state-sponsored screening programs also play a role, particularly in newborn screening and awareness campaigns. Many states mandate newborn screening for sickle cell conditions.
For individuals planning a family or during pregnancy, pre-conception or prenatal care providers, such as obstetricians/gynecologists (OB/GYNs) or genetic counselors, can arrange testing. They can guide individuals through the process, explain the implications of results, and discuss options. It is advisable to inquire about appointment scheduling, potential referral requirements from a doctor, and insurance coverage beforehand.
Interpreting Results and Next Steps
Once the blood sample is analyzed, results will indicate the presence or absence of sickle cell hemoglobin. A “negative result” means that no sickle cell trait or disease was detected, indicating the individual likely has normal hemoglobin.
A diagnosis of “sickle cell trait” means the individual carries one copy of the gene for sickle cell hemoglobin (HbS) and one copy of the normal hemoglobin gene (HbA). People with sickle cell trait usually do not experience symptoms, but they can pass the gene to their children. If both parents have the sickle cell trait, there is a 25% chance with each pregnancy that their child will inherit two copies of the gene and have sickle cell disease.
A diagnosis of “sickle cell disease” indicates the individual has inherited two copies of the abnormal hemoglobin S gene, or one copy of HbS and another abnormal hemoglobin gene, leading to the condition. This diagnosis requires ongoing specialized medical care to manage symptoms and prevent complications. Post-test counseling with a healthcare provider or genetic counselor is important to understand the specific implications of the results. For trait carriers, genetic counseling can help explain inheritance patterns and reproductive options. For those diagnosed with sickle cell disease, the next steps involve connecting with a hematologist or other specialists for a comprehensive care plan, which may include regular monitoring, pain management strategies, and other treatments.