MYO5B mutations cause cholestasis with normal serum gamma‐glutamyl transferase activity in children without microvillous inclusion disease

Some patients with microvillus inclusion disease due to myosin 5B (MYO5B) mutations may develop cholestasis characterized by a progressive familial intrahepatic cholestasis‐like phenotype with normal serum gamma‐glutamyl transferase activity. So far MYO5B deficiency has not been reported in patients with such a cholestasis phenotype in the absence of intestinal disease. Using a new‐generation sequencing approach, we identified MYO5B mutations in five patients with progressive familial intrahepatic cholestasis‐like phenotype with normal serum gamma‐glutamyl transferase activity without intestinal disease. Conclusion: These data show that MYO5B deficiency may lead to isolated cholestasis and that MYO5B should be considered as an additional progressive familial intrahepatic cholestasis gene. (Hepatology 2017;65:164‐173).