A 46 year old man presents with chronic back pain and dark staining of his underwear. He reports that his urine turns black if left standing in the toilet. Physical examination reveals bluish black discoloration of the ear cartilage and sclerae. Which of the following enzyme deficiencies is the most likely cause of this disorder?
- A)Dopamine beta hydroxylase
- B)Homogentisate oxidaseGABARITO
- C)Branched chain alpha ketoacid dehydrogenase
- D)Tyrosinase
- E)Phenylalanine hydroxylase
Explicação
This patient has alkaptonuria caused by homogentisate oxidase deficiency in tyrosine degradation. Accumulated homogentisic acid polymerizes in connective tissue, causing ochronosis and degenerative arthropathy, and oxidizes in urine to produce dark discolorati... Ver explicação completa e trilha adaptativa →