Compound Heterozygous MYO5B Mutation, a Cause of Infantile Cholestasis: A Case Report.

Infantile cholestasis is a common clinical problem in early infancy characterised by impairment in bile formation and/or flow. It requires prompt evaluation for underlying aetiology to initiate appropriate management. Although biliary atresia remains the most important aetiology, metabolic and monogenic disorders are increasingly identified with advances in diagnostic genetic testing. Progressive familial intrahepatic cholestasis disorders characterised by defects in biliary canalicular transport are among the most common monogenic disorders of cholestasis. Homozygous or compound heterozygous mutation in the Myosin 5B gene leading to a progressive familial intrahepatic cholestasis-like phenotype with or without intestinal features of microvillus inclusion disease is a relatively recently identified disorder. The incidence of these newer variants of progressive familial intrahepatic cholestasis is not yet known due to the paucity of studies. We report an uncommon cause of refractory cholestasis reported in a girl who presented with severe pruritus as the primary manifestation.