MYO5B Pathogenic Variants Found to Cause Intestinal Symptoms Without Microvillus Inclusion Disease in a Child Who Previously Underwent Liver Transplantation for PFIC-like Cholestasis.

Myosin 5B (MYO5B) pathogenic variants are associated with microvillus inclusion disease (MVID), a congenital disorder of the enterocyte characterized by intractable diarrhea (5). A subset of MVID patients also have cholestatic liver disease. Conversely, some patients may have isolated cholestasis without gastrointestinal symptoms (2). Such patients have been described to have a progressive familial intrahepatic cholestasis (PFIC)-like phenotype with normal serum gamma-glutamyl transferase. We report a novel case in which MYO5B pathogenic variants were discovered by whole exome sequencing in a post-liver transplant patient who originally presented with PFIC-like cholestasis and chronic intermittent diarrhea without ultrastructural evidence of microvillus inclusion disease.