Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) is an autosomal recessive marrow failure syndrome associated with exocrine pancreatic insufficiency and leukemia predisposition. Bone marrow failure typically manifests with neutropenia, but anemia, thrombocytopenia, or aplastic anemia may also develop. Additional organ systems, such as liver or bone, may also be affected. Clonal cytogenetic abnormalities, particularly those involving chromosome 7 such as monosomy 7 or isochromosome 7, may develop. Mutations in the SBDS gene are found in approximately 90% of patients meeting clinical diagnostic criteria. SBDS is a highly conserved gene of unknown function. Studies of the yeast orthologue YLR022c and structurally related proteins suggest a role in RNA metabolism. In human cells, the SBDS protein localizes to both the cytoplasm and the nucleus, and shuttles in and out of the nucleolus in a cell cycle-dependent manner. A discussion of diagnostic workup, medical management, and treatment is presented.