Pearson's marrow/pancreas syndrome: haematological features associated with deletion and duplication of mitochondrial DNA.

Pearson's marrow/pancreas syndrome (PS) is a rare, often fatal, disorder of infancy that is characterized by impaired bone marrow, exocrine pancreatic, hepatic and renal function. Large-scale rearrangements of mitochondrial DNA (mtDNA) are present in blood. We report a patient with PS who has predominantly impaired haemopoiesis manifesting as sideroblastic anaemia, vacuolization of bone marrow precursors, and neutropenia. 77% of bone marrow mtDNA was rearranged (64% deleted an 13% duplicated). We suggest that rearrangements of mtDNA should be sought in all infants presenting with sideroblastic anaemia.