Pearson Syndrome


Pearson Syndrome
Pearson syndrome is caused by mitochondrial DNA deletions,
affecting the cells ofmany different organ systems.
(Image source)
Pearson syndrome is a rare disorder that affects the cells of many different organ systems, due to mitochondrial DNA deletions. Patients with this syndrome have anemia, trouble with their ability to absorb nutrients, and trouble with their ability to regulate electrolytes in their bodies. They may also have variable amounts of liver, kidney, and endocrine (hormonal) failure. It affects boys and girls equally, and is passed on through sporadic mitochondrial DNA mutation. 

Symptoms

Pearson syndrome is most often diagnosed in infancy. The following symptoms may be present immediately after birth, and many of them will become worse over time:
 
1. Pale skin color due to anemia (small numbers of red blood cells)
2. Frequent infections due to neutropenia (small numbers of white blood cells)
3. Easy bruising or bleeding due to thrombocytopenia (small numbers of platelets)
4. Diarrhea due to malabsorption (this occurs when the intestines cannot absorb nutrients)
5. Failure to grow caused by endocirine disturbances (growth hormone deficiency, low thyroid or parathyroid function)

Cause

The cause of Pearson syndrome is complex and not well understood. It is known that patients are missing pieces of DNA from their mitochondria, meaning that cells cannot work properly. The mitochondria do not produce enough energy to build other cells, to clear out waste products, or to build enzymes.

Diagnosis

Making the diagnosis of Pearson syndrome begins with measuring the levels of red blood cells, white blood cells and platelets in the patients blood. Blood tests will also be performed to measure the levels of enzymes (proteins with digestive function) made by the pancreas. A sample of your the stool may be examined to determine if malabsorption is present. Urine studies and liver studies may also be performed to detect renal or hepatic involvement. To provide the final diagnosis, however, a bone marrow biopsy will be performed. 

Treatment

No specific therapy exists for patients with Pearson syndrome, but treatment focuses on treating its complications. Patients may need a transfusion of red blood cells when levels gets too low, and erythropoietin can help make more red blood cells. Filgrastim, or G-CSF, can also be used to help your make more white blood cells. If there are complications with the pancreas, enzymes can be replaced orally. Great care will need to be taken to prevent the patient from developing infections, and antibiotic therapy will be needed if they have a fever.

Prognosis

In the past, patients with Pearson syndrome were not expected to live beyond the age of 3. The most common cause of death was severe infection or metabolic crisis. With careful monitoring and treatments, however, children can now live longer lives. Some patients with Pearson syndrome recover from their anemia and survive beyond childhood.
 
For further information on Pearson syndrome, please visit Madisons Foundation, or Medscape.