People with Down syndrome frequently show abnormalities in the blood cells which include the red cells (cells that carry oxygen throughout the body), white cells (infection-fighting cells) and platelets (cells that help to stop bleeding). Some of the changes found in the blood cells of people with Down syndrome can be associated with other medical complications seen among this patient population. Many times, however, the same blood cell abnormalities are diagnosed without an apparent cause. In many instances, the abnormalities resolve spontaneously after a period of time. This is especially common among newborn babies with Down syndrome. Some patients will have persistent changes in the blood cells throughout their lives. Evaluation and treatment by a hematologist/oncologist may be necessary.

What are the Most Common Hematologic Abnormalities Identified in Patients With Down Syndrome?

The most common blood cell abnormalities diagnosed in patients with Down syndrome include: polycythemia (also known as erythrocytosis), macrocytosis, thrombocytopenia, thrombocytosis, leucopenia, leukemoid reactions and transient myeloproliferative disorder.

 

Polycythemia

Polycythemia is an elevated number of red blood cells and is frequently seen in newborn babies with Down syndrome. In some of them, the elevation in the number of red blood cells is associated with some types of congenital heart defects but the great majority of babies with Down syndrome who develop polycythemia do not have an associated heart defect. Typically, the polycythemia will resolve within the first few months of life especially if it is not associated with an underlying medical condition. In general, polycythemia will not cause significant problems. Occasionally, treatment is necessary if the number of red cells is extremely elevated and the blood gets too thick.

 

Macrocytosis

Macrocytosis is enlargement of the red blood cells and is very common in newborns with Down syndrome. It persists throughout life in about two thirds of individuals with Down syndrome. Macrocytosis should not cause any adverse medical effect.

 

Thrombocytopenia

Thrombocytopenia is a decreased number of platelets and is a common diagnosis for babies with Down syndrome. Having a platelet count that is too low may predispose an individual to bleeding. Under some circumstances, patients with significant thrombocytopenia may require platelet transfusions.

 

Thrombocytosis

Thrombocytosis is an elevated number of platelets. This is a rare hematologic finding in newborn babies with Down syndrome. When it occurs, it usually does not cause any medical problem and will resolve spontaneously within the first weeks of life.

 

Luekopenia

Leukopenia is a low number of white cells. The number of white cells tends to be slighter lower than the normal range in about one third of individuals with Down syndrome. There is some concern that this may increase the risk for infections among patients with Down syndrome but this has not been clearly proven through medical research yet.

 

Leukemoid Reaction

Leukemoid reactions is a very elevated number of white cells. Babies born with Down syndrome can present with this blood cell abnormality within the first few months of life. It typically resolves spontaneously but in some instances it may be associated with a more serious medical condition.

 

Transient Myeloproliferative Disorder (TMD)

This is a medical condition found almost exclusively in newborns with Down syndrome and it results from rapid growth of abnormal white cells. An estimated 10-20% of babies born with Down syndrome are diagnosed with TMD. The abnormal cells may go away without treatment, or they may need treatment. The choice of treatment or no treatment depends on whether certain harmful characteristics of the disease are observed in the baby. Some of the treatments that have been used include leukophoresis (a procedure that filters abnormal cells from a baby’s blood) and chemotherapy (anti-cancer drugs). In the great majority of patients, the prognosis of TMD is good with complete resolution of the disease without any treatment. A few patients with TMD do not show improvement and develop leukemia. In some patients, leukemia develops years after TMD is resolved. Because TMD is potentially cancerous, children who are diagnosed with this disorder should be monitored closely for years after the signs and symptoms of the condition resolve.
 

What are Some Oncologic Disorders in People With Down Syndrome?

Individuals with Down syndrome are at increased risk for the development of precancerous conditions such as myelodysplastic syndrome, potentially cancerous conditions such as transient myeloproliferative disorder and cancerous conditions like leukemia.

 

Myelodysplastic Syndrome (MDS)

Myelodysplastic Syndrome (MDS) is a pre-cancerous condition that originates in the bone marrow. The diagnosis of MDS is suspected when the blood cells in the bone marrow start showing changes like a decrease in the platelet count (thrombocytopenia), an increase in the size of the RBC (macrocytosis), decrease in the number of red cells and level of hemoglobin (anemia), or a decrease or increase in the number of white cells.

If untreated, MDS will progress to leukemia. The time frame for the development of leukemia ranges from months to years. The evaluation and treatment of MDS should be discussed with a hematologist/oncologist.

 

Transient Myeloproliferative Disorder (TMD)

This is a medical condition found almost exclusively in newborns with Down syndrome and it results from rapid growth of abnormal white cells. An estimated 10-20% of babies born with Down syndrome are diagnosed with TMD. The abnormal cells may go away without treatment, or they may need treatment. The choice of treatment or no treatment depends on whether certain harmful characteristics of the disease are observed in the baby. Some of the treatments that have been used include leukophoresis (a procedure that filters abnormal cells from a baby’s blood) and chemotherapy (anti-cancer drugs). In the great majority of patients, the prognosis of TMD is good with complete resolution of the disease without any treatment. A few patients of TMD do not show improvement and develop cancer in the blood or leukemia. In some patients, leukemia develops years after TMD is resolved. Because TMD is potentially cancerous, children who are diagnosed with this disorder should be monitored closely for years after the signs and symptoms of the condition resolve.

 

Leukemia

Leukemia is a cancer of the blood cells. It develops when young and abnormal cells, called ‘blasts’, crowd out normal bone marrow cells and spread into the blood stream. The ‘blasts’ can also spread to the brain, spinal cord and other organs.

A patient diagnosed with leukemia should be evaluated by a hematologist/oncologist who will determine the subtype of leukemia and the type of therapy needed.

 

How is Cancer Treated in Patients With Down Syndrome?

Individuals with Down syndrome are more sensitive to some chemotherapy agents and some of the side effects are more severe for patients with Down syndrome when compared to the general population. Therefore, these patients should be watched more closely when receiving certain types of chemotherapy medicines.

 

Are There Other Types of Cancers People With Down Syndrome can Develop?

Patients with Down syndrome probably have an increased risk for the development of germ cell tumors (a rare type of cancer found in the ovaries or testes that may also be found in other areas of the body such as the brain, chest or abdomen). There is increasing concern that retinoblastoma (a rare type of cancer which develops in the cells of the retina) may be diagnosed more frequently among people with Down syndrome. By far, the most common type of cancer encountered in patients with Down syndrome is leukemia.