How is SDS specifically diagnosed?
• Reduced digestive enzyme production by the pancreas (“Pancreatic insufficiency”), which can be measured by various laboratory or x-ray tests: • Low serum trypsinogen and isoamylase (key digestive enzymes made by the pancreas) • Abnormal amounts of fat in the stool • Low pancreatic enzymes after stimulation of the pancreas • Small or fatty pancreas on ultrasound or CT scan imaging of the pancreas • Bone marrow failure • Low neutrophils in blood on at least 3 occasions • May have low hemoglobin and/or platelets • Genetic testing • The disease appears to be inherited in an autosomal recessive manner. This means that illness occurs only if a person has two abnormal (mutant) copies of the SDS gene. Laboratories can now identify the specific genetic “error” (or mutation) in some patients, in a gene called SBDS, which stands for Shwachman Bodian Diamond Syndrome.
