Shwachman syndrome: exocrine pancreatic dysfunction and variable phenotypic expression.
OBJECTIVE
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.
Mack
D R
DR
Department of Pediatrics, Hospital for Sick Children, Toronto, Canada.
Forstner
G G
GG
Wilschanski
M
M
Freedman
M H
MH
Durie
P R
PR
D000015:Abnormalities, Multiple / Q000503:physiopathology*; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010182:Pancreatic Diseases / Q000503:physiopathology*; D010641:Phenotype; D011379:Prognosis; D013577:Syndrome