Biochemistry Which of the following enzymes is deficient in Criggler Najer syndrome? A UDP glucoronyl transferase 1 B UDP glucoronyl transferase 2 C Bilirubin synthase D Heme synthase 💡 Explanation Which of the following enzymes is deficient in Criggler Najer syndrome? ✓ Correct Answer: A. UDP glucoronyl transferase 1