What are the IBMFS disorders?
Pearson Syndrome
Patients with Pearson Syndrome may have poor food absorption
(malabsorption) and low
white
blood cell counts (neutropenia). Low red cell
counts (anemia)
can be a major problem, and low platelet
counts (thrombocytopenia)
can also occur. Symptoms are often present in infancy. Liver and
kidney disease usually develop. Examination of the bone marrow under
the microscope reveals characteristic holes ("vacuoles")
in many cells. The disease is caused by a loss, or deletion,
of large pieces of DNA
from tiny structures in the substance of cells, which are called mitochondria.
Mitochondria are responsible for producing much of the energy that
cells need in order to function normally.
- What are the major findings on physical examination?
- Short stature.
- What is the age at diagnosis?
- Patients have been diagnosed from birth to 7 years of age
- The diagnosis is usually made in the first year of life.
- What is the pattern of bone marrow failure?
- The bone marrow fails to produce a specific type of white
blood cell called "neutrophils."
When these cells are present in lower than normal numbers in
the bloodstream, the condition is called "neutropenia."
- Low red cell count (anemia)
- Low
platelet
count (platelets are the cells which help the blood to clot)
- Patients may develop aplastic
anemia when all 3 types of cells (red cells, white cells and platelets) are abnormally low because the bone
marrow is not producing them.
- What kinds of cancer
develop?
- No cancers have been reported in the medical literature to
date in patients with Pearson Syndrome. However, persons with
this disease may be at increased risk of leukemia.
- How is Pearson Syndrome specifically diagnosed?
- Blood counts are performed to detect the lower than normal
numbers of particular cell types.
- Bone marrow cells have holes ("vacuoles") in them
and and an immature type of red cell containing excess iron
deposits ("ring sideroblasts") is detected.
- Mutation analysis (genetic testing)
- Laboratories can now identify the genetic "error" (mutation)
in some patients, due to loss or deletion of some of the DNA from mitochondria.
|