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Disease Profile

Pearson syndrome

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

<1 / 1 000 000

US Estimated

Europe Estimated

Age of onset






Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Sideroblastic anemia with marrow cell vacuolization and exocrine pancreatic dysfunction (formerly); Pearson's marrow/pancreas syndrome; Pearson's syndrome;


Blood Diseases; Congenital and Genetic Diseases; Digestive Diseases;


Pearson syndrome affects many parts of the body but especially the bone marrow and the pancreas. Pearson syndrome affects the cells in the bone marrow (hematopoietic stem cells) that produce red blood cells, white blood cells, and platelets. Having too few red blood cells (anemia), white blood cells (neutropenia), or platelets (thrombocytopenia) can cause a child to feel weak and tired, be sick more often, bruise more easily and take a longer time to stop bleeding when cut. Pearson syndrome also affects the pancreas, which can cause frequent diarrhea and stomach pain, trouble gaining weight, and diabetes. Some children with Person syndrome may also have problems with their liver, kidneys, heart, eyes, ears, and/or brain.[1][2][3][4]

Pearson syndrome is caused by a change (mutation) in the mitochondrial DNA. These mutations can make it hard for the cells of the body to make energy. Most cases of Pearson syndrome happen for the first time in a family which means it is not passed down from either parent (de novo mutation).[1][2][3][4]

Diagnosis of Pearson syndrome is possible through a bone marrow biopsy, a urine test, or a special stool test. Genetic testing can be completed to confirm the diagnosis. Treatment options include frequent blood transfusions, pancreatic enzyme replacement therapy, and treatment of infections. Sadly, many children with Pearson syndrome die during infancy. Some children may survive into later childhood, but may go on to develop Kearns-Sayre syndrome.[1][2][3][4]


Pearson syndrome affects the cells in the bone marrow (hematopoietic stem cells) that produce red blood cells, white blood cells, and platelets. When there aren't enough healthy red blood cells (anemia), the body becomes very weak, the child's skin is pale, and the child is very tired (fatigued).[1][2][3] Children with Pearson syndrome are anemic because the iron which should be in the hemoglobin, ends up instead in the mitochondria. Without hemoglobin, these cells (ringed sideroblast) cannot carry oxygen. When a person has too few white blood cells (neutropenia), it is more difficult for the body to fight infection, which can cause frequent colds and sickness. When a person doesn't have enough platelets (thrombocytopenia), the blood does not clot as well, which can cause a child to take a long time to stop bleeding. Some children with Pearson syndrome have problems with all three blood cell types, but other children may not.[1][2][3][4]

Pearson syndrome may also affect the pancreas, which is a gland found in our abdomen or belly. The pancreas is responsible for making special proteins called digestive enzymes which break down the food we eat. The pancreas also produces hormones (insulin and glucagon) which help control the sugar levels in our blood. A child with Pearson syndrome can have symptoms such as frequent diarrhea and stomach pain, and it may be difficult for them to gain weight. They may also have diabetes if the pancreas doesn't produce enough insulin. Some children with Person syndrome may also have problems with their liver, kidneys, heart, eyes, ears, and/or brain.[1][2][3][4]

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Bone marrow hypocellularity
Bone marrow failure
Elevated lactate:pyruvate ratio
Increased blood alanine
Increased serum alanine

[ more ]

High urine lactic acid levels
Low blood neutrophil count
Low neutrophil count

[ more ]

Increased immature red blood cells
Increased number of immature red blood cells

[ more ]

Severe infection
30%-79% of people have these symptoms
Low number of red blood cells or hemoglobin
Disease of the heart muscle
Corneal stromal edema
Exocrine pancreatic insufficiency
Inability to properly digest food due to lack of pancreatic digestive enzymes
Enlarged liver
Increased CSF lactate
Increased serum lactate
Postnatal growth retardation
Growth delay as children
Renal insufficiency
Renal failure
Renal failure in adulthood

[ more ]

Small for gestational age
Birth weight less than 10th percentile
Low birth weight

[ more ]

Increased spleen size
Low platelet count
5%-29% of people have these symptoms
Cardiac conduction abnormality
Clouding of the lens of the eye
Cloudy lens

[ more ]

Chronic diarrhea
Decreased serum bicarbonate concentration
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood

[ more ]

Diabetes mellitus
Poor swallowing
Swallowing difficulties
Swallowing difficulty

[ more ]

Elevated hepatic transaminase
High liver enzymes
Global developmental delay
Glucose in urine
Growth hormone deficiency
Hearing impairment
Hearing defect

[ more ]

Hepatic failure
Liver failure
Hepatic steatosis
Fatty infiltration of liver
Fatty liver

[ more ]

Hydrops fetalis
Low blood calcium levels
Low blood potassium levels
Low blood magnesium levels
Low blood phosphate level
Underactive thyroid
Lactic acidosis
Increased lactate in body
Malabsorption of Vitamin B12
Muscular hypotonia of the trunk
Low muscle tone in trunk
Eye muscle paralysis
Pancreatic fibrosis
Low blood cell count
Pigmentary retinopathy
Poor suck
Poor sucking
High urine protein levels
Protein in urine

[ more ]

Drooping upper eyelid
Fat in feces
1%-4% of people have these symptoms
Adrenal insufficiency
Cafe-au-lait spot


Pearson syndrome is a genetic disease, meaning that it is caused by a problem in the DNA. Most DNA is contained in the center of our cells (nuclear DNA ), but a small part of our DNA is contained in a part of our cells called the mitochondria. Mitochondria make the energy for the cells in our body by combining oxygen with sugars and fats that come from the food we eat.[1][2][3]

Changes in mitochondrial DNA make it hard for the cell to make energy. Pearson syndrome is usually caused by deletions of a part of the mitochondrial DNA (pieces of the DNA are missing). Most cases of Pearson syndrome occur by mistake (de novo mutation) during very early development of the embryo. Sometimes the deletion occurs in the egg cell. This means that the disease was not passed down or inherited from either parent and no other family member has the disease.[1][2][3][5]

DNA contains genes which are the instructions (genetic code) the cell uses to make proteins. Proteins do most of the work in cells of our body. Many of the proteins coded by the genes in the mitochondrial DNA are needed to help make energy. When pieces of mitochondrial DNA are missing, important genes are missing, so the cell does not make energy like it should.


Many tests may be needed to diagnose Pearson syndrome, including a bone marrow biopsy to look for signs of sideroblastic anemia or a bowel movement sample to measure the amount of fat in the stool. The doctors may also test the urine to check for certain organic acids which would be a sign of metabolic acidosis. Finally, genetic testing for changes or mutations in mitochondrial DNA would confirm the diagnosis. The results of the genetic test may be especially important. Although Pearson syndrome is usually caused by deletions of mitochondrial DNA, duplication of mitochondrial DNA can also cause symptoms of Pearson syndrome. Whether the condition is caused by a deletion or duplication of DNA may affect how the disease progresses.[1][2][3][6]


Unfortunately, there is no cure for Pearson syndrome, and the goal of treatment is to decrease the seriousness of symptoms so the child can live as healthy and as long of a life as possible. Children affected by Pearson syndrome may require frequent blood transfusions to help supply the body with healthy red blood cells. Pancreatic enzyme replacement may also help to replace the missing enzymes needed to digest food, or insulin injections may be necessary to treat diabetes. It is important that children affected by Pearson syndrome avoid other people who are sick with viral or bacterial infections, as these children cannot fight off illnesses as well as other children can.[1][2][6] Other treatments depend on the specific symptoms presented by each person with Pearson syndrome. It may be necessary to see specialists for the liver, kidneys, heart, and pancreas. Physical or occupational therapy may be helpful, especially in children who live past infancy.[1][2][3]

Unfortunately, a stem cell transplant has not been shown to be helpful in curing a disease that affects many systems in the body like Pearson syndrome does. It is, however, important to ask your doctors about any new or promising treatments for Pearson syndrome.[1]


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Organizations Providing General Support

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

      • Genetics Home Reference contains information on Pearson syndrome. This website is maintained by the National Library of Medicine.
      • The National Cancer Institute provides the most current information on cancer for patients, health professionals, and the general public.

        In-Depth Information

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Pearson syndrome. Click on the link to view a sample search on this topic.


          1. Rogers ZR. Pearson Syndrome. Medscape Reference. May 5 2016; https://emedicine.medscape.com/article/957186-overview.
          2. Farruggia P, Di Cataldo A, Pinto RM, Palmisani E, Macaluso A, Lo Valvo L, Cantarini ME, Tornesello A, Corti P, Fioredda F, Varotto S, Martire B, Moroni I, Puccio G, Russo G, Dufour C, and Pillon M. Pearson Syndrome: A Retrospective Cohort Study from the Marrow Failure Study Group of A.I.E.O.P. (Associazione Italiana Emato-Oncologia Pediatrica). Journal of Inherited Metabolic Disease Reports. August 4, 2015; 26:37-43. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4864774/.
          3. Mancuso M, Orsucci D, Angelini C, Bertini E, Carelli V, Comi GP, Donati MA, Federico A, Minetti C, Moggio M, Mongini T, Santorelli FM, Servidei S, Tonin P, Toscano A, Bruno C, Bello L, Caldarazzo Ienco E, Cardaioli E, Catteruccia M, Da Pozzo P, Filosto M, Lamperti C, Moroni I, Musumeci O, Pegoraro E, Ronchi D, Sauchelli D, Scarpelli M, Sciacco M, Valentino ML, Vercelli L, Zeviani M, Siciliano G. Redefining phenotypes associated with mitochondrial DNA single deletion. Journal of Neurology. May 2015; 262(5):1301-1309. https://www.ncbi.nlm.nih.gov/pubmed/25808502.
          4. What is Pearson Syndrome?. The Champ Foundation. May 5, 2016; https://www.thechampfoundation.org/. Accessed 10/26/2016.
          5. Goldstein A, Falk M. Mitochondrial DNA Deletion Syndromes. GeneReviews. Updated Jan 31, 2019; https://www.ncbi.nlm.nih.gov/books/NBK1203/. Accessed 11/21/2011.
          6. Crippa BL, Leon E, Calhoun A, Lowichik A, Pasquali M, and N Longo. Biochemical abnormalities in Pearson syndrome. American Journal of Medical Genetics. Part A.. March 2015; 167A(3):621-628. https://www.ncbi.nlm.nih.gov/pubmed/25691415.

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