Shwachman-Diamond syndrome is an inherited condition that affects many parts of the body, particularly the bone marrow, pancreas, and bones.

The major function of bone marrow is to produce new blood cells. These include red blood cells, which carry oxygen to the body's tissues; white blood cells, which fight infection; and platelets, which are blood cells that are necessary for normal blood clotting. In Shwachman-Diamond syndrome, the bone marrow malfunctions and does not make some or all types of white blood cells. A shortage of neutrophils, the most common type of white blood cell, causes a condition called neutropenia. Most people with Shwachman-Diamond syndrome have at least occasional episodes of neutropenia, which makes them more vulnerable to infections, often involving the lungs (pneumonia), ears (otitis media), or skin.