Gastroduodenal Crohn's Disease, also known as upper gi crohn's disease, is related to duodenal obstruction and gastritis, and has symptoms including nausea, vomiting and weight loss. An important gene associated with Gastroduodenal Crohn's Disease is ATP12A (ATPase H+/K+ Transporting Non-Gastric Alpha2 Subunit), and among its related pathways/superpathways are Allograft rejection and THC Differentiation Pathway. Affiliated tissues include small intestine and stomach.