The pediatric hematology program at St. Louis Children’s Hospital diagnoses and treats childhood blood disorders, including sickle cell disease, bleeding disorders and blood cancers.

Red Blood Cell Disorders

These blood disorders affect the number or quality of red blood cells your child’s body produces.


This common condition, in which the body lacks enough red blood cells or hemoglobin, affects about 20 percent of American children. Hemoglobin, the major protein in red blood cells,  carries oxygen throughout the body. There are many types of anemia, which have different causes and range from mild to severe, including:

Iron deficiency anemia

This is the most common form of anemia. Causes may include a low-iron diet, gastrointestinal problems, excessive menstrual bleeding or bleeding after an injury or surgery.

Megaloblastic (pernicious) anemia

This form of anemia causes bone marrow to produce fewer red blood cells. The cells that do form don’t live as long as they should. The most common cause of pernicious anemia is a lack of folic acid or vitamin B-12.

Hemolytic anemia

In people who have hemolytic anemia, their red blood cells are destroyed faster than their bodies can create new ones. Some types of hemolytic anemia are mild enough that treatment isn’t necessary, while other types are more severe.

  • Sickle cell disease: This inherited genetic condition is usually diagnosed through newborn screening. Sickle cell causes damaged red blood cells, which can lead to anemia, infections, pain and other symptoms.
  • Thalassemia: This genetic form of anemia affects production of hemoglobin. The two main types are:
    • Alpha thalassemia: Defects to the alpha globin genes cause alpha thalassemia. There are three types, based on the number of defective genes a child inherits: alpha thalassemia major, hemoglobin H disease and alpha thalassemia carrier.
    • Beta thalassemia: Defects to the beta globin genes cause beta thalassemia. The severity of this condition depends on the type: Beta thalassemia major (Cooley's anemia), beta thalassemia intermedia and thalassemia minor.

Other red blood cell disorders

  • Lead poisoning: Exposure to lead can cause serious health problems, including neurological issues and developmental delays. Paint chips and dirt are common sources of lead exposure. It is more serious for children, whose bodies absorb it more easily.
  • Polycythemia: This rare but serious disorder causes bone marrow to produce too many red blood cells, which often leads to blood clots. This condition is not inherited, but it may be more common in some families.

White Blood Cell Disorders

These blood disorders affect the number or quality of white blood cells your child’s body produces.

  • Agranulocytosis: In people with this condition, bone marrow cannot make enough white blood cells, which can lead to serious infections. Some children are born with agranulocytosis, while others develop it from autoimmune disorders, cancer or medications.
  • Neutropenia: A low amount of neutrophils, a type of white blood cell that fights infection, makes a child more susceptible to infections. Neutropenia may be inherited or acquired. Inherited forms include severe congenital neutropenia and cyclic neutropenia. Acquired neutropenia may be caused by chemotherapy, radiation therapy or autoimmune disorders.

Blood cancers

Children with blood cancers are treated through the Siteman Kids oncology program, a partnership between St. Louis Children’s Hospital and the Siteman Cancer Center.

Bone Marrow Failure Disorders (Aplastic Anemia)

Bone marrow failure disorders, which can be inherited or acquired, affect marrow production of blood cells.

  • Diamond Blackfan anemia: Usually diagnosed in the first year of life, this rare condition prevents the body from producing enough red blood cells. It is caused by mutations that affect the production of ribosomes, which are critical for production of hemoglobin and other proteins within red cells. About half of all cases are inherited, while the cause of the other half is unknown.
  • Fanconi anemia: This rare genetic disorder prevents bone marrow from producing enough new red blood cells. Fanconi anemia is associated with birth defects, bone marrow failure (aplastic anemia) and increased risk of leukemia and other certain other types of cancer.

Platelet and Clotting Factor Disorders

Platelets, a type of blood cell, work with blood proteins called clotting factors to stop bleeding. These disorders affect the number or function of platelets. Both too much clotting and not enough clotting can cause serious medical problems.

Bleeding disorders

These blood disorders stop blood from coagulating (clotting), leading to excess bleeding.

  • Hemophilia: Children with this genetic disorder do not have enough clotting factor, so their blood does not clot properly, causing them to bleed too much. There are different types of hemophilia and they range in severity
  • Thrombocytopenia: Children with this condition have low numbers of platets in the bloodstream, which can cause excessive bruising and bleeding. Most children won’t require treatment, but some may need blood transfusions.
    • Immune thrombocytopenic purpura (ITP): Too few platelets in the blood can lead to excessive bleeding. ITP is most common in children ages 2-6, and may appear after an infection like chicken pox.
  • Von Willebrand disease (VWD): Lack of clotting factors causes children with this inherited disorder to bleed too much. Symptoms and treatments vary depending on the severity of the condition.
  • Other coagulation factor deficiencies: We manage patients with deficiencies of other coagulation factors such as Factor VII and Factor XI.

Excessive clotting disorders (thrombophilia)

These inherited blood disorders cause excess blood clotting, including an increased risk of deep vein thrombosis (DVT). Thrombophilia is the general term for a predisposition to blood clots. Types of thrombophilia include:

  • Antithrombin deficiency: This inherited disorder can cause abnormal blood clots, usually after adolescence. Antithrombin deficiency can lead to DVT or pulmonary embolism.
  • Factor V leiden: The most common blood clotting disorder, factor V leiden increases the risk of DVT. However, most people with the condition do not develop serious blood clots.
  • Protein C deficiency: Many with this blood clotting disorder do not have symptoms. However, babies with the severe type of Protein C deficiency can develop life-threatening widespread blood clotting throughout the body.
  • Protein S deficiency: Some with this condition may have an increased risk of DVT. Some babies with the severe type of Protein S deficiency can develop life-threatening widespread blood clotting throughout the body.
  • Prothrombin thrombophilia: Few patients diagnosed with this condition will develop blood clots. However, it can increase the likelihood of DVT or pregnancy complications, including miscarriage.

Make an Appointment with a Hematologist

Call 800.678.5437 to make an appointment or request an appointment online.