What Is Shwachman Diamond Syndrome?

A Brief Review of Symptoms, Diagnostic Testing, and Treatment

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Mother holding newborn. Mayte Torres/Creative RF/Getty Images

Shwachman Diamond Syndrome (SDS) is one of the inherited bone marrow failure syndromes associated with neutropenia and pancreatic dysfunction. It is sometimes referred to as Shwachman Bodian Diamond or Shwachman Diamond Oski Syndrome. It is inherited in an autosomal recessive fashion; the affected child must inherit the mutated gene from both parents.   

What Are the Presenting Symptoms?

  • Diarrhea, particularly oily diarrhea called steatorrhea. This results from the pancreas being unable to make pancreatic enzymes required to break down nutrients in food so that they can be absorbed.
  • Recurrent infections secondary to neutropenia
  • Short stature
  • Elevation in liver enzymes
  • Skeletal abnormalities
  • Anemia
  • Thrombocytopenia

How Is It Diagnosed?

SDS can be challenging to diagnose as all signs and symptoms do not have to occur at the same time. Steatorrhea may be the first symptom with neutropenia developing months later. Patients may see several specialists (gastrointestinal, hematology, endocrinology) in order to get a proper diagnosis.  

It is not uncommon for steatorrhea and inability to gain weight (also called failure to thrive) to be the first symptoms of this condition. This presentation is very similar to cystic fibrosis, so a sweat test may be performed. Compared to cystic fibrosis, in SDS the sweat test will be negative. Additional testing might include fecal elastase (a lab test on the stool) and trypsin (blood work), both which measure the pancreatic function. This type of pancreatic dysfunction is called exocrine pancreas dysfunction (compared to diabetes, which is endocrine pancreatic dysfunction).

 

Neutropenia will be identified on a complete blood count (CBC). In general, at presentation only the neutrophil count will be low. However, with time some patients may develop pancytopenia (anemia and thrombocytopenia in addition to neutropenia). A bone marrow aspirate and biopsy will be required to rule out other reasons for neutropenia.

Patients with SDS are at risk for developing myelodysplastic syndrome or acute myeloid leukemia (AML), so bone marrow evaluations will be performed on a regular basis to monitor for these conditions.  

SDS has a clinical diagnosis based on presence of a cytopenia (neutropenia, anemia, or thrombocytopenia) and pancreatic dysfunction. Genetic testing can be sent to confirm the diagnosis, but it is not required.  

What Are the Treatments?

Treatments focus on the two main body systems affected: the pancreas and the bone marrow.

Pancreatic dysfunction is treated similarly to cystic fibrosis.  

  • Oral pancreatic enzymes are taken with meals (and sometimes snacks) to improve absorption of nutrients from the diet. As a patient ages, the pancreatic function may improve and pancreatic enzymes may no longer be necessary.  
  • Additionally, fat soluble vitamins (A, D, E, K) levels might be low and require replacement.

Bone marrow failure:  

  • Antibiotics: Similar to other medical conditions with neutropenia, fever is a medical emergency. Fever requires evaluation by a medical professional, blood work (complete blood count and blood cultures at a minimum), and at least one dose of intravenous (IV) antibiotics. If the neutropenia is severe (absolute neutrophil count < 500), admission for IV antibiotic until infection can be ruled out.
  • Filgrastim (granulocyte colony stimulating factor): This can be given as a subcutaneous (under the skin) injection daily to increase the ANC and prevent infections.  
  • Blood transfusions: Red blood cell or platelet transfusions can be given for patients that develop anemia and/or thrombocytopenia.  
  • Bone marrow transplantation: If the neutropenia progresses to pancytopenia, bone marrow transplantation is the only curative therapy available. Optimally, bone marrow transplantation should occur prior to the development of AML as prognosis goes down significantly if AML develops.  

 

Source:

Rogers ZR. Shwachman-Diamond Syndrome. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. (Accessed on May 28, 2016.)

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