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. (H epatology 2017;65:164‐173).