Pearson syndrome

Pearson syndrome (also known as Pearson marrow-pancreas syndrome) is a rare, severe multisystem mitochondrial disorder caused by large-scale deletions (or, less commonly, rearrangements) of mitochondrial DNA (mtDNA). It typically presents in infancy with refractory sideroblastic anemia and exocrine pancreatic dysfunction. The disease affects multiple organ systems because mitochondria are essential for energy production in virtually all cells. The bone marrow is prominently involved, leading to transfusion-dependent anemia, neutropenia, and thrombocytopenia. Vacuolization of marrow precursors and the presence of ringed sideroblasts on bone marrow examination are characteristic findings. Beyond the hematologic manifestations, Pearson syndrome causes exocrine pancreatic insufficiency with malabsorption, failure to thrive, and chronic diarrhea. The liver, kidneys, and endocrine system may also be affected, with metabolic acidosis (particularly lactic acidosis) being a common and sometimes life-threatening complication. Hepatic dysfunction, renal tubular acidosis, and insulin-dependent diabetes mellitus can develop over time. Neurological involvement may also occur, though it is more prominent in patients who survive infancy and transition to a Kearns-Sayre syndrome phenotype. The prognosis of Pearson syndrome is generally poor, with many affected children dying in infancy or early childhood due to metabolic crises, sepsis, or organ failure. Treatment is primarily supportive and includes red blood cell and platelet transfusions, pancreatic enzyme replacement therapy, bicarbonate supplementation for acidosis, and nutritional support. There is no curative therapy currently available, although hematopoietic stem cell transplantation has been explored in select cases. Patients who survive the early hematologic phase may develop features of Kearns-Sayre syndrome, including progressive external ophthalmoplegia, pigmentary retinopathy, and cardiac conduction defects.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Pearson syndrome