inherits one sickle cell gene—from either parent but not both—he or she will have sickle cell trait and be referred to as a carrier . People who live with sickle cell trait do not experience the symptoms or problems experienced by those who live with sickle cell disease. When parents who both have the trait have a pregnancy together, there is a one in four (25%) chance the child will have sickle cell disease, a two in four (50%) chance the child will have sickle cell trait, and a one in four (25%) chance the child will have normal hemoglobin chains (no disease or trait). The chances are the same with each pregnancy, so it is possible to have more than one child with sickle cell disease. n WHAT ARE THE TYPES OF SICKLE CELL DISEASE? Although there are many types of sickle cell disease, four types are most common: sickle cell anemia (HbSS), sickle hemoglobin C (HbSC), sickle beta-zero thalassemia (HbS-ß0 thal), and sickle beta-plus thalassemia (HbS-ß+ thal). Sickle Cell Anemia Sickle cell anemia, also known as Hemoglobin SS (HbSS), is the most common and severe form of sickle cell disease. In this form, each parent passes on the mutated gene for sickle-shaped cells (hemoglobin S). As a result, the body only produces the abnormal sickle hemoglobin.
Sickle Hemoglobin C (HbSC) Hemoglobin C is abnormal hemoglobin caused by another gene mutation. If one parent passes along a mutated hemoglobin S gene, and the other passes along a mutated hemoglobin C gene, the child is diagnosed with hemoglobin SC, or HbSC. Hemoglobin C (Hb C) is not concerning unless it is matched with HbS. Patients with HbSC tend to experience milder symptoms than those diagnosed with HbSS. However, severity varies from patient to patient, and some patients may experience the same severe symptoms as those with HbSS.
Sickle Beta Thalassemia Beta (ß) thalassemia is another inherited disorder that affects the amount and quality of hemoglobin made by the body. The combination of the beta thalassemia gene with the sickle cell gene leads to a diagnosis of sickle beta thalassemia, which is a form of sickle cell disease. Sickle beta-zero thalassemia (HbS-ß0 thal) means there is no normal hemoglobin being made by the body. It usually is a serious form of sickle cell disease. Sickle beta-plus thalassemia (HbS-ß+ thal) means normal hemoglobin is being made but only in a small amount. This usually is a milder form of sickle cell disease, although severity varies from person to person.
3
Powered by FlippingBook