VPS33B and cholestasis: He had the same mutations that were identified in his brother’s VPS33B. Case 3: A 24-year-old man born to nonconsanguineous Japanese parents was suspected to have progressive familial intrahepatic cholestasis 1 (PFIC1) in his childhood on the basis of low GGT cholestasis, renal tubular dysfunction, sensory deafness, mental retardation, and persistent itching.