Wednesday, February 6, 2008

What is Shwachman-Diamond Syndrome?

Shwachman-Diamond Syndrome (SDS), first described in 1964, is a rare, genetic (autosomal recessive), multi-systemic disorder affecting the pancreas, bone marrow, and skeleton. The most common symptoms are pancreatic dysfunction (malabsorption), low neutrophil count and short stature. Other organs may also be involved in some SDS patients. Shwachman-Diamond Syndrome affects people differently and not all people with SDS have all of these symptoms. In Infancy, the first symptoms are usually loose, foul smelling, greasy stools and failure to gain weight and grow normally. The pancreas fails to produce the enzymes essential to digest food properly. Because of the exocrine pancreatic dysfunction (malabsorption), the child does not absorb enough nutrients, most commonly the fat-soluble vitamins, to grow and develop normally. Oral enzyme replacement therapy helps these children to digest their food, but many still need to take special vitamin supplements. Improving nutritional status does not necessarily improve the growth of children with Shwachman-Diamond Syndrome.

The bone marrow, where blood cells are produced, is also affected in Shwachman-Diamond Syndrome. White blood cells, which fight infection, are most commonly affected. Neutropenia is the most common hematological abnormality in SDS, though all blood cell lines may be affected. Anemia and blood clotting problems are also common in SDS patients. Because of the bone marrow dysfunction, these children are at a greater risk of developing life-threatening infections. Shwachman-Diamond Syndrome is considered to be a bone marrow failure syndrome, because up to 30% of these children will develop leukemia or aplastic anemia.