Pearson syndrome

Mitochondria are parts of a cell that help turn the energy we get from food into energy that the body can use. They are also important in the communication between body parts and creating other materials the body needs. Mitochondrial conditions can cause a variety of signs and symptoms in many parts of the body, particularly those that use a lot of energy like muscles and the brain.

Pearson syndrome occurs when a large part of the DNA found inside of the mitochondria (mitochondrial DNA, or mtDNA) is deleted. This results in the bone-marrow being unable to create mature blood cells, as well as general metabolic instability.

• Pearson marrow-pancreas syndrome
• Pearson’s marrow/pancreas syndrome
• Sideroblastic anemia with marrow cell vacuolization and exocrine pancreatic dysfunction
• Pearson’s syndrome

Pearson syndrome occurs when a large piece of mitochondrial DNA is missing, or deleted. This is almost always due to a new genetic change in a baby, rather than a genetic change that is passed down from a parent.

Both boys and girls can have Pearson syndrome.

Pearson syndrome is thought to be very rare, and the exact frequency is unknown. Less than 1,000 people have been diagnosed with Pearson syndrome.

Both Male and Female

Always check with your provider if new symptoms appear or you are concerned.

Pearson syndrome causes a range of signs and symptoms. These may differ greatly, even in people who have similar genetic changes. The signs and symptoms of Pearson syndrome also depend heavily on the levels of genetic change found in each tissue.

If there is a high level of deletion (sometimes called ‘high load’), in the bone marrow, people can have:

• Sideroblastic anemia (the body is unable to make enough red blood cells, causing low oxygen in the body’s tissues). This can cause weakness, fatigue, and other symptoms.
  Thrombocytopenia (low levels of platelets, which help form clots to stop bleeding)
  Neutropenia (low neutrophils, a type of white blood cell that fights infection)
  Pancytopenia (low levels of red blood cells, white blood cells, and platelets)
• High load in the pancreas can cause exocrine insufficiency. This is where the pancreas doesn’t create enough of the enzymes that break down food. This can cause gas, bloating, pain and diarrhea. Babies can also have “fatty poops,” since the body can’t break down fats properly. Ultimately, this leads to nutritional deficiencies since the body can’t absorb the nutrients it needs from food, and ultimately leads to failure to thrive and growth issues.

Other signs and symptoms of Pearson syndrome can include:

• Chronic infections
• Lactic acidosis
• Short stature
• Kidney disease
• Liver disease
• Diabetes
• Eye changes in older patients
• Genetic load can change in tissues over time. This can cause someone to develop new signs and symptoms of disease later in life, specifically a Kearns-Sayre-like phenotype.

Pearson syndrome can be diagnosed by:

• Detailed physical examination and medical history.
• Laboratory testing looking at blood cells, lactate, and other metabolic levels
• Testing to look for mitochondrial DNA deletions
• Imaging tests like MRI or ultrasound of the pancreas, liver and kidney

Pearson syndrome is not included on newborn screening panels.

No

Before beginning any treatment or therapy, please consult with your physician.

There is currently no FDA-approved therapy for Pearson syndrome.

Treatment and management of Pearson syndrome is symptomatic and supportive. This may include:
Blood transfusions, monitoring blood levels, and bleeding precautions
Infection prevention
Pancreatic enzyme replacement
Vitamin supplementation
Nutrition support with feeding support and gastrostomy tube if required.
Standard treatment of lactic acidosis
Standard management of kidney conditions, including certain supplementations
Standard management of liver disease
Diabetes and growth support

Individuals living with Pearson syndrome typically work with several healthcare providers regularly based on their symptoms, which may include:

• Hematology
• Gastroenterology
• Hepatology
• Endocrinology
• Nephrology
• Social work
• Genetics
• Optometry and ophthalmology
• Physical and occupational therapy
• Neurology

It is important that all those living with or caring for someone with Pearson syndrome have an emergency protocol letter. These letters, which are written and signed by a doctor, share details about prescribed treatment during a crisis and in emergency room settings.

• Endocrinology
• Gastroenterology
• Hematology
• Nephrology
• Neurology
• Ophthalmology
• Physical and occupational therapy

• Pearson syndrome | About the Disease | GARD
• Pearson syndrome: MedlinePlus Genetics

Connecting with others impacted by a rare disease allows for vital information to be shared about day-to-day life, prevents isolation, and gives hope. Please contact MitoAction for peer support opportunities at 888-MITO-411 or email mito411@mitoaction.org.

Other resources we recommend are:

• New Patient Kit for Mitochondrial Conditions
• Planning and Preparation
• Monthly Expert Series
• Energy in Action Podcast