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

Some patients with microvillusinclusion disease due to myosin 5B (MYO5B) mutations may develop cholestasischaracterized by a progressive familial intrahepatic cholestasis-like phenotype with normal serum gamma-glutamyl transferaseactivity. So far MYO5B deficiency has not been reported in patients with such a cholestasisphenotype 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 transferaseactivity without intestinal disease. Conclusion: These data show that MYO5B deficiency may lead to isolated cholestasisand that MYO5B should be considered as an additional progressive familial intrahepatic cholestasisgene. ( Hepatology2017;65:164-173).