Which of the following is caused by defective tyrosine metabolism?: (A) Richner-Hanha syndrome, (B) Neonatal tyrosinemia, (C) Alkaptonuria, (D) All of the above
Answer is D. Metabolic diseases of tyrosine catabolism include tyrosinosis, Richner-Hanha syndrome, neonatal tyrosinemia, and alkaptonuria. Ref: Harper 28th edition, chapter 29.