Odd facies with high prominent forehead and deep-set eyes, chronic cholestasis, and paucity of interlobular bile ducts, butterfly-shaped vertebral arches, peripheral pulmonary stenosis, renal failure, and hepatic failure in children. Supportive measures are ursodeoxycholic acide and phenobarbital; eventually liver transplantation is required. Associated with chromosome microdeletion 20p12- and interstitial gene deletion 20p11.23p11.23. Also marked by pulmonary artery stenosis.