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Mutations in the SBDS gene have been identified in about 90 percent of people with the characteristic features of Shwachman-Diamond syndrome. This gene provides instructions for making a protein whose function is unknown, although it is active in cells throughout the body. Researchers suspect that the SBDS protein may play a role in processing RNA (a molecule that is a chemical cousin of DNA). This protein may also be involved in building ribosomes, which are cellular structures that process the cell's genetic instructions to create proteins. It is unclear how SBDS mutations lead to the major signs and symptoms of Shwachman-Diamond syndrome.
In cases where no SBDS mutation is found, the cause of this disorder is unknown.
The mode or type of inheritance of Shwachman-Diamond syndrome in individuals without an identified SBDS mutation is unknown.