Megaloblastic anemia is a form of anemia characterized by very large red
blood cells and a decrease in the number of those cells. Anemias are blood disorders that occur when the body has
fewer red blood cells than normal. Red blood cells carry oxygen throughout the
body using a protein called hemoglobin. If there aren’t enough of these cells
or this protein, anemia results.
Usually, megaloblastic anemia is due to acquired deficiency
in vitamin B12 or folic acid. The deficiency can be related to inadequate
dietary intake of these B vitamins or poor intestinal absorption. Rarely,
megaloblastic anemias are the result of medications or inherited defects in the
transport/metabolism of vitamin B12 or folic acid.
Pernicious anemia is a type of megaloblastic anemia in which
the body isn’t able to absorb vitamin B12 due to a lack of intrinsic factor in stomach
secretions. Intrinsic factor is needed for the body to absorb vitamin B12.
For all types of megaloblastic anemia, in addition to the red blood cells
being large, the inner contents of each cell are not completely developed. This
malformation causes the bone marrow to produce fewer cells, and sometimes the
red blood cells die earlier than the 120-day life expectancy.
Children and young adults with megaloblastic anemia are
treated through the Blood Disorders Center at Dana-Farber/Boston
Children's. Our program brings together world-renown pediatric
hematology specialists and support staff from across Dana-Farber/Boston Children’s,
including pediatric hematologist/oncologists, hematopathologists, hematology
nurse practitioners, social workers and designated hematology patient
coordinators. For many appointments and certain procedures, your child can also
receive care at one of Boston Children's satellite
Each child may experience symptoms of pernicious anemia differently.
Some children with pernicious anemia do not have symptoms, or they may be mild.
Common symptoms of the condition include:
It is important to understand
that some symptoms of megaloblastic anemia may resemble those of other more
common medical problems or other blood disorders. Because some of these
symptoms can also point to other conditions, and because anemia itself can be a
symptom of another medical problem, it’s important to have your child evaluated
by a qualified medical professional for an accurate diagnosis and prompt
Megaloblastic anemia most commonly results from an acquired nutritional
deficiency or inability to absorb nutrients. Common causes include:
In rare cases, megaloblastic
anemia is the result of inherited problems:
Your child's doctor may suspect megaloblastic anemia after taking a complete
medical history and physical examination of your child. Megaloblastic anemia is
diagnosed through a physical exam and other tests, including:
may be other diagnostic tests that your doctor will discuss with you depending
on your child's individual situation. After we complete all necessary tests,
our experts meet to review and discuss what they have learned about your
child's condition. Then we will meet with you and your family to discuss the
results and outline the best possible treatment options.
Megaloblastic anemia treatment typically includes:
Of course, your child's team of doctors will help
determine the best approach for your child's unique situation, based on a
number of factors including:
scientists are conducting innovative research on anemias and red blood cell disorders.
We have a long track record of innovation, and Dana-Farber/Boston Children’s
Cancer and Blood Disorders Center is considered a world leader in
laboratory and clinical research on blood disorders. Our researchers were the first to clone the gene responsible for thiamine-responsive
megaloblastic anemia (TRMA), a type of congenital megaloblastic anemia.
Children with acquired megaloblastic anemia typically do
well with treatment. It’s important to start treatment early, especially in
vitamin B12 deficiency, as nerve damage can become permanent if treatment does
not begin within six months of the onset of symptoms. With ongoing care and
proper treatment, most children with acquired megaloblastic anemia recover
fully. Outcomes for congenital (inherited) forms of megaloblastic anemia depend
on the exact diagnosis.
We have a number of resources at Dana-Farber/Boston
Children’s to help you and your family through this time. From the first visit
through follow-up care, our nurses will be on hand to walk you through your
child’s treatment and help answer any questions you may have.