Purpose: Congenital malformations of the intestine include malrotation, atresia, duplications and persistence of vestigial structures that may be isolated or associated with other abnormalities. Heterotopic gastric mucosa (HGM) of variable extension may occur anywhere along the GI axis including the biliary tract, and is commonly found in Meckel's diverticulum or duplications of the GI tract. Symptoms of HGM include pain, bleeding, ulceration and perforation, partial obstruction and intussuception. Adenocarcinoma arising from HGM has also been described. A 4.5 year old boy presented with abdominal pain, melena and anemia. He had history of prematurity, surgery for duodenal atresia, annular pancreas, intestinal malrotation and subsequently for lysis of adhesions. His brother had similar abnormalities, recurrent GI bleeding and died at 7 years of age following intestinal perforation due to extensive HGM found post mortem (Pediatr Dev Pathol 2000; 3: 277-80). The parents are Portuguese and came from the same village. Two great-grandfathers were first cousins. Upon admission our patient received blood transfusions and was stabilized. A Tc-99m pertechnetate scan was compatible with extensive small bowel HGM. GI series and abdominal CT scan showed extensive thickening and diffuse nodular irregularity of the small bowel and ileum. EGD and colonoscopy were negative for HGM. Fasting gastrin levels were normal. Because he seemed to have extensive intestinal HGM similar to his brother, and had history of intestinal adhesions, he was not considered a candidate for surgery. He was started on PPI, H2 blockers and iron supplementation. With this treatment, he has had persistent occult blood in the stools but has been free of major GI bleeding or abdominal pain for 8 years. His linear growth has been between the 10-25th percentiles and his weight along the 5th percentile. Repeated GI imaging has shown no significant changes. He developed nonketotic hyperglycemia 4 years after his admission and has been treated with insulin. Serum insulin, cortisol and ACTH were normal. Anti Gad65, IcA512, anti-insulin antibodies and gene mutations for MODY were reported negative. Extensive HGM has been reported to be associated with malrotation in one case (J Pediatr Surg 2005; 40: 1654-7) and with diabetes in another case (J Pediatr Gastroenterol Nutr 2007; 44: 494-7). Familial intestinal malrotation or atresia are rare and to our knowledge there are no reports of familial HGM. The presence of duodenal atresia, intestinal malrotation and extensive HGM in two siblings described here, suggest a new heritable syndrome. Although diabetes was not described in the first sibling, diabetes may be part of the syndrome.