Identifying Genetic Mutations That Cause Extrahepatic Portosystemic Shunts in Dogs

Extrahepatic portosystemic shunt is a congenital liver disorder that results in severely impaired liver growth and atrophy of hepatocytes, leading to reduced hepatic function and eventual death. The disorder occurs frequently in small dog breeds and has a proven genetic background. Two chromosomal regions have been shown to be associated with this disorder. Eight genes are found in these regions, two of which have been proven to be involved in the formation of vascular structures during embryogenesis in zebrafish. The investigators will clarify the gene mutations that cause extrahepatic portosystemic shunt and will then develop a DNA test that would help breeders eradicate this severe disease in several dog breeds. The findings may also provide insight into other chronic progressive liver diseases.