Pearson syndrome is a mitochondrial disease characterized by sideroblastic anemia and exocrine pancreas dysfunction. It is caused by a deletion in mitochondrial DNA Pearson Syndrome is classified as a mitochondrial disease because it consists of several overlapping syndromes that are caused by mutations of mitochondrial DNA. Specifically, Pearson Syndrome is a combination of syndromes that involves the bone marrow and the exocrine pancreas. Pearson syndrome is very rare (< 100 cases so far reported worldwide).
Pearson Syndrome is a form of sideroblastic anemia associated with exocrine pancreas dysfunction. With Pearson Syndrome, the bone marrow fails to produce white blood cells called neutrophils. The syndrome also leads to anemia, low platelet count, and aplastic anemia. Other clinical features are failure to thrive, pancreatic fibrosis with insulin-dependent diabetes and exocrine pancreatic deficiency, muscle and neurologic impairment, and, frequently, early death. It is usually fatal in infancy. The few patients who survive into adulthood often develop symptoms of Kearns-Sayre syndrome syndrome (ophthalmoplegia with abnormal ocular movements)
Pearson syndrome is transmitted by maternal inheritance. The father of an individual with Pearson Syndrome is not at risk for carrying the mtDNA mutation. The mother carries the trait, but does not have the mtDNA deletion in her tissues.