A Rare Case of Gould Syndrome Presenting With Gastrointestinal Bleeding in a Pediatric Patient.

Gould syndrome, caused by COL4A1/COL4A2 mutations, is a rare multisystem disorder characterized by basement membrane defects leading to vascular fragility, cerebral small vessel disease, seizures, and renal involvement. While vascular complications are well-described, gastrointestinal bleeding remains exceedingly rare. We describe a four-year-old female with a known diagnosis of Gould syndrome who presented with hemodynamically significant hematochezia. Colonoscopy demonstrated tortuous submucosal vascular lesions consistent with colonic varices in the sigmoid colon, which were treated with bipolar probe electrocautery; an additional non-bleeding varix was noted at the hepatic flexure. Computed tomography (CT) angiography and time-resolved imaging of contrast kinetics magnetic resonance imaging (TRICKS MRI) revealed abnormal venous structures in the mesentery and bowel without evidence of arteriovenous malformation or portal-systemic shunting, congruent with endoscopic findings. There was no clinical or radiographic evidence of portal hypertension. This case expands the phenotypic spectrum of Gould syndrome by providing detailed evidence of gastrointestinal venous abnormalities and highlights gastrointestinal bleeding as a potential underrecognized manifestation of COL4A1/2-related disease.