Radiographic diagnosis of Shwachman-Diamond Syndrome in a neonate. W. Smith, A. Amalfitano, C. Miller, A. Patterson. Divisions of Medical Genetics and Pediatric Radiology, Duke University Medical Center, Durham, NC.

   Shwachman-Diamond syndrome (SDS) is a rare, autosomal recessive disorder characterized by pancreatic insufficiency, bone marrow dysfunction and skeletal dysplasia. Diagnosis is usually made in childhood secondary to pancreatic or blood disorders. Restrictive thoracic dystrophy (RTD) in the neonatal period has been retrospectively reported in several patients with SDS. We report a neonate with RTD who was subsequently diagnosed with SDS. This African American male was the 2.6kg (25th%) product of a normal 38 week pregnancy to a G10P5 mother; birth length 45cm (10th%), OFC 33.5cm (50-75th%). He had symmetric rhizomelic limb shortening and a very narrow, bell shaped chest: inter-nipple distance 6.3cm (<3rd %), chest circumference 28cm (3-50th %). Radiographs obtained at age 6 days demonstrated markedly shortened AP and transverse chest diameters with small, short, anteriorly cupped ribs. The thoracic and lumbar vertebrae were ovoid with end-plate sclerosis. There was significant metaphyseal dysplasia of the long bones with deep cupping but no irregularity. A tentative diagnosis of SDS was made based solely on the skeletal findings. Subsequent investigations revealed low serum trypsin and increased stool fat consistent with pancreatic insufficiency. By five weeks of age he developed recurrent vomiting and diarrhea, failure to thrive and a significant anemia: hgb 4.8 mg/dl, hct 15%. Physical examination demonstrated hepatosplenomegaly. A midgut nonrotation was diagnosed and he underwent surgical repair. Simultaneous liver biopsy showed extensive macrovesicular steatosis with canalicular cholestasis and abundant iron. Postoperatively he remained ventilator and blood product dependent. Due to neutropenia he developed concurrent fungal, coagulase negative staphylococcal, and enterococcal sepsis and died at age 10 weeks. Post-mortem histology of the pancreas was characteristic of SDS with highly vacuolated lobules, atrophic acinar spaces and preserved islets. This patient, in whom a prospective radiologic diagnosis of SDS was made as a neonate, suggests that disease severity may be positively correlated with the radiographic features and the degree of RTD.