What is Shwachman-Diamond syndrome (SDS)?
Shwachman-Diamond syndrome (SDS) is a rare condition affecting a child’s bone marrow, pancreas and bones. It is inherited (passed down in families) and sometimes involves other organs such as the liver and teeth.
Effects on blood and bone marrow
Children with SDS can develop bone marrow failure. The job of the bone marrow is to make blood cells that the body needs, including white blood cells, red blood cells and platelets. Bone marrow failure means the marrow inside the bones doesn’t make enough of one or more kinds of blood cells. Children with SDS can:
- Have problems making neutrophils (NOO-truh-fills). These are a type of white blood cell that fights infections.
- Develop low red blood cell counts, called anemia. Red blood cells are important for the body because they carry oxygen to all the vital organs and tissues.
- Have low platelet counts, called thrombocytopenia (THROM-bow-sye-toe-PEE-nee-uh). Platelets are important because they help blood clot and, therefore, help stop bleeding.
- Develop aplastic anemia. This is a condition where the bone marrow fails to make all three types of blood cells (white blood cells, red blood cells and platelets).
- Shwachman-Diamond syndrome increases the risk of developing blood cancers like myelodysplastic syndrome (MDS) and leukemia. MDS is a preleukemia condition.
Effects on pancreas
Shwachman-Diamond syndrome can also affect how the pancreas works. The pancreas makes enzymes that help the body digest food. Children with Shwachman-Diamond syndrome may not make enough of these enzymes, a condition called exocrine pancreatic insufficiency. As a result, your child does not digest food well. This can lead to problems with growth and development because the body isn’t getting enough nutrients.
Effects on bone growth
Many children with Shwachman-Diamond syndrome have problems with the growth and development of their bones, especially their hips and knees. Some children are born with small rib cages and short ribs. This can cause serious problems with breathing. Children may also have problems with low bone density (called osteopenia) where bones are at increased risk of breaking.
Shwachman-Diamond Syndrome in Children
Shwachman-Diamond syndrome is an inherited (genetic) condition. It is a recessive condition tied to one gene. That means the parents of a child with Shwachman-Diamond syndrome do not have the disease, but they each carry one gene that causes the condition. This gene has been found and is named the SBDS gene. Parents can pass this gene on to their children. A child with SDS must inherit two of these genes, one from each parent.
Mutations in the SBDS gene cause 90% of the cases of SDS. The other 10% of those with SDS have a normal SBDS gene and are diagnosed based on their symptoms and lab tests.
Babies usually have symptoms by the time they are 4 to 6 months old. Doctors may find the problem early in life, but some people are not diagnosed until they are adults.
Doctors and researchers at Seattle Children’s and our partner institutions are working hard to understand what causes SDS. Learn more about research at Seattle Children’s.