Shwachman syndrome: Exocrine pancreatic dysfunction and variable phenotypic expression

Background & Aims: Shwachman syndrome is an inherited condition with multisystemic abnormalities, including exocrine pancreatic dysfunction. The aim of this study was to evaluate the occurrence and progression of features in a large cohort of patients, Methods: Clinical records of 25 patients with Shwachman syndrome were reviewed, Results: Mean birth weight (2.92 +/- 0.51 kg) was at the 25th percentile, However, by 6 months of age, mean heights and weights were less than the 5th percentile, After 6 months of age, growth velocity was normal, Severe fat maldigestion due to pancreatic insufficiency was present in early life (fecal fat, 26% +/- 17% of fat intake; age, <2 years). Serial assessment of exocrine pancreatic function showed persistent deficits of enzyme secretion, but 45% of patients showed moderate age-related improvements leading to pancreatic sufficiency, Neutropenia was the most common hematologic abnormality (88%), but leukopenia, thrombocytopenia, and anemia were also frequently encountered. Patients with hypoplasia of all three bone marrow cellular lines (n = 11) had the worst prognosis; 5 patients died, 2 of sepsis and 3 of acute myelogenous leukemia, Other findings included hepatomegaly and/or abnormal liver function test results and skeletal abnormalities, Conclusions: A wide and varied spectrum of phenotypic abnormalities among patients with Shwachman syndrome is described. Pancreatic acinar dysfunction is an invariable abnormality, Patients with severe bone marrow involvement may have a guarded prognosis.