Hereditary Disorders

Core Concepts

Sickle cell disease: one changed protein, many consequences

Sickle cell disease results from a change in the gene for the beta-globin part of hemoglobin. The abnormal hemoglobin (hemoglobin S) makes red blood cells change shape — from flexible disks into stiff crescents — when they are deoxygenated, dehydrated, cold, or stressed by infection. Sickled cells are fragile (they break apart, causing anemia) and sticky (they clog small vessels, blocking blood flow). Blocked flow causes vaso-occlusive crises: severe pain in bones, joints, chest, or abdomen, often with no visible injury. Repeated blockages damage organs over a lifetime, and the spleen, which filters sickled cells, becomes scarred and stops working (functional asplenia), leaving the person dangerously vulnerable to certain infections. Acute chest syndrome, a lung complication with chest pain, fever, and breathing difficulty, is a leading cause of death and time-critical. Crisis nursing focuses on objective pain assessment and timely analgesia per orders, warmth, hydration, and incentive spirometry, while avoiding cold, dehydration, and hypoxia and watching closely for chest pain or respiratory change. People with sickle cell trait (one gene) are generally healthy — not the same as the disease.

Thalassemia: missing building blocks

Thalassemia is a group of disorders in which the body makes too little of one of the two protein chains that form hemoglobin — alpha or beta. With an unbalanced supply of building blocks, red cells are made poorly, die early, and anemia results. Severity spans a wide range: trait (one affected gene) is usually mild or silent; major forms cause severe anemia from early childhood. Chronic anemia drives the marrow to work overtime, which can expand bone and cause characteristic facial changes, and the spleen enlarges as it destroys abnormal cells. Many people with severe thalassemia depend on regular transfusions, and transfusions over years deposit iron in the heart, liver, and other organs — so iron overload and its monitoring are major long-term concerns. Nursing care includes transfusion support with reaction monitoring and supporting families through a lifetime of treatment decisions made with the hematology team.

Hemophilia A and B: missing clotting factors

Hemophilia A and hemophilia B are X-linked bleeding disorders caused by deficiency of clotting factor VIII (A) or factor IX (B). Without the missing factor, the coagulation cascade stalls and clots form slowly, so bleeding is prolonged. The hallmark is bleeding into joints (hemarthrosis) and muscles — often after minor injury or even spontaneously — which causes pain, swelling, and, over years, joint damage if not treated. Bleeding after surgery, dental work, or trauma can be severe, and bleeding inside the skull, while rare, is catastrophic. Nursing priorities are bleeding precautions (gentle handling, avoiding unnecessary injections, prompt pressure to puncture sites), recognizing joint or muscle bleeding early, teaching about factor replacement per the hematology plan, and coordinating with the care team before any procedure. Aspirin and other antiplatelet drugs are generally avoided in bleeding disorders — a provider and pharmacy decision — and the person should be able to tell any new clinician about their condition.

von Willebrand disease: the most common inherited bleeding disorder

Von Willebrand disease (VWD) affects both halves of hemostasis: von Willebrand factor helps platelets stick to injured vessel walls, and it also carries factor VIII in the blood. Because platelet plug formation is impaired, the bleeding pattern is different from hemophilia — VWD features mucosal and skin bleeding: easy bruising, frequent nosebleeds, bleeding gums, heavy menstrual bleeding, and prolonged bleeding after cuts, dental work, or surgery. It is usually milder than hemophilia, and many people are only diagnosed after a procedure goes wrong or a family member is diagnosed. Nursing care centers on recognizing the bleeding history, bleeding precautions, coordinating with hematology before procedures, and teaching that heavy menstrual bleeding is not something to simply "put up with."

G6PD deficiency: red cells without a shield

Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that protects red blood cells from oxidative damage. In G6PD deficiency, an X-linked condition, red cells are normal most of the time but break down (hemolyze) when exposed to oxidative stress — certain infections, fava beans, and a list of medications that the pharmacist and provider review carefully. The result is an acute hemolytic episode: fatigue, jaundice, dark urine, and falling hemoglobin days after the trigger. Prevention is trigger avoidance, and the nurse's teaching role is substantial: the person should know the condition, carry the diagnosis, and have every new medication checked against the trigger list by a pharmacist. Most people with G6PD deficiency are entirely healthy between episodes.

Nursing threads across hereditary blood disorders

Four threads run through all of these conditions: person-first language (a person has sickle cell disease; their identity is not their diagnosis), objective nonjudgmental pain and symptom assessment — especially in sickle cell disease, where pain is real, severe, and frequently undertreated — anticipatory teaching of crisis warning signs (severe pain, fever, chest pain, bleeding, dark urine), and care coordination, with genetic counseling and family screening offered by the care team. Scope note: assessment, precautions, education, and coordination are nursing responsibilities; factor replacement, transfusions, and genetic testing require provider orders and specialist involvement.

Common Confusions