BACKGROUND: Prader-Willi syndrome (PWS) is a genetic disorder characterized by initial muscular hypotonia and feeding difficulties, and later an insatiable appetite, hyperphagia and obesity along with mild to moderate intellectual impairment. Affected individuals’ food-seeking behavior and suspected delayed gastric emptying can lead to gastric dilatation with subsequent necrosis and perforation.

CASE REPORT: We present the case of a 5-year-old boy diagnosed with Prader-Willi syndrome at neonatal age due to muscular hypotonia, who started growth hormone therapy at 20 months. He presented with two episodes of a rapidly progressing gastric dilatation that led to abdominal hypertension and secondary shock at the age of 2 and 5. No large amount of food was eaten before any of the episodes, and he had abdominal pain and vomiting on both occasions. On arrival at the emergency room, a nasogastric tube was placed and aspiration of food material was performed. Abdominal X-ray and CT scan revealed massive gastric dilatation. He was admitted at the Pediatric Intensive Care Unit and after a variable period of fasting, tolerated oral intake and could be discharged.

CONCLUSIONS: Gastric dilatation due to gastroparesis in PWS is a rare complication. However, it is a life-threatening situation and physicians should therefore maintain a high level of suspicion for gastric dilatation when patients present with warning symptoms such as abdominal pain or discomfort and vomiting.

Keywords: Gastric Dilatation, Gastroparesis, intra-abdominal hypertension, Prader-Willi Syndrome