Pearson et al described a syndrome which is now known to be associated with a deletion of mitochondrial DNA resulting in a defect in the mitochondrial respiratory chain.
Classic features of Pearson’s syndrome:
(1) refractory sideroblastic anemia with macrocytosis and transfusion dependency
(2) variable degree of neutropenia and thrombocytopenia
(3) vacuolated marrow precursors
(4) exocrine pancreatic insufficiency with variable malabsorption
Additional findings may include:
(1) lactic acidosis with high lactate to pyruvate molar ratios
