Endoscopic findings in patients with Shwachman-Diamond syndrome: A report from the North American Shwachman-Diamond syndrome registry.

Objectives: Shwachman-Diamond syndrome (SDS) is an inherited bone marrow failure disorder, and its endoscopic phenotype is poorly defined. We sought to characterize endoscopic findings in patients with genetically confirmed SDS. Methods: Retrospective registry study of 45 patients with biallelic Shwachman-Bodian-Diamond syndrome mutations and evaluable endoscopic procedures. Clinical, laboratory, imaging, endoscopic reports, and biopsy findings were extracted from patient medical records. Results: Among 45 patients with genetically confirmed SDS, 102 endoscopic procedures were performed, most commonly esophagogastroduodenoscopy (EGD, 58.8%). The leading indication was diarrhea and/or steatorrhea (23.6%). Abnormal biopsy findings were most frequent in patients with dysphagia/dyspepsia or gastrointestinal bleeding and were strongly associated with elevated C-reactive protein and abnormal hepatic enzymes. Most pre-procedural imaging studies were normal (63.4%). Pre-hematopoietic stem cell transplant (HSCT) biopsies were largely normal, with occasional mild acute or chronic inflammation in the esophagus, stomach, and duodenum. In contrast, post-HSCT biopsies showed more diverse abnormalities, including inflammation, basal crypt apoptosis, and graft-versus-host disease (GVHD)-associated changes. Central pathology review also identified rare findings such as adenoviral infection and mild or equivocal GVHD in post-transplant samples. Conclusions: Endoscopic evaluation in patients with SDS demonstrates heterogeneous histopathologic findings, with diagnostic yield influenced by clinical indication, laboratory abnormalities, and transplant status. Routine endoscopy in asymptomatic or nonspecifically symptomatic patients may have limited value, whereas targeted evaluation based on symptoms or supportive laboratory findings may improve diagnostic yield. These findings provide updated insight into gastrointestinal manifestations of SDS and may help guide clinical decision-making regarding endoscopic evaluation in this rare disease.