Shwachman Diamond syndrome

• Congenital exocrine pancreatic insufficiency; chronic diarrhoea, malabsorption and growth failure associated with neutropenia.

• Bone marrow failure not usually trilineage, though platelets and red cells can be involved.

• Bone marrow varies—may be dysplastic/hypo/aplastic.

• Probably autosomal recessive, but no gene yet identified.

• Psychomotor delay common.

Diagnosis

• Exclude cystic fibrosis (by normal sweat test).

• Exclude Fanconi's anaemia (by normal chromosome fragility).

• Pearson's syndrome clinically similar with severe pancreatic insufficiency but with anaemia rather than neutropenia and marrow shows ring sideroblasts and vacuolisation of red and white cell precursors.

Treatment

• Supportive with pancreatic enzymes, G-CSF and antibiotics.

• Greatly increased risk (up to 30%) of progression to MDS/leukaemia (AML > ALL).

• Limited experience with BMT for aplasia/leukaemia; may be increased risk of cardiotoxicity—ventricular fibrosis seen at autopsy in 2/5 patients who died post BMT.

Outlook

Depends on development of severe aplasia or leukaemia; long survivors few if so. Pancreatic insufficiency improves as childhood progresses.

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