Combined Mutations of Canalicular Transporter Proteins Causing Low Phospholipid-Associated Cholelithiasis and Transient Neonatal Cholestasis in an Infant.

Low phospholipid-associated cholelithiasis syndrome is characterized by the development of cholelithiasis in early adulthood (<40 years of age) but is rarely diagnosed in childhood. It is associated with gene sequence variants in the ABCB4 gene encoding the multidrug resistance protein 3 which are mostly heterozygous. Transient neonatal cholestasis has been reported with heterozygous mutations in both ABCB4 and ABCB11 (Bile Salt Exporter Protein). We report a 3-month-old male with cholelithiasis and transient neonatal cholestasis in the setting of combined pathogenic heterozygous mutations in the genes ABCB4 and ABCB11. Initiation of ursodeoxycholic acid therapy led to a resolution of the cholestasis and gall stones. Our case highlights the complex nature of the genetics of cholestatic disorders.