Final answer:
Leukemia is the most common hematologic disorder of infancy and childhood. It is characterized by the production of abnormal white blood cells.
Step-by-step explanation:
Leukemia is the most common hematologic disorder of infancy and childhood. It is a group of cancers that affect the blood-forming tissues in the bone marrow. Leukemia is characterized by the production of large numbers of abnormal white blood cells. Symptoms of leukemia may include excessive bleeding and bruising, fatigue, fever, and an increased risk of infections.