Hem/Onc Quiz #16: Hemoglobin Synthesis and Porphyrias

1. A 30-year-old woman presents to the clinic complaining of painful, blistering skin lesions on her hands and forearms that worsen with sun exposure. She mentions that her urine turns dark upon standing. She has no significant past medical history but notes that her father had similar symptoms. Which of the following enzymes is most likely deficient in this patient?

Question 1 of 5

2. A 25-year-old man is brought to the emergency department with severe abdominal pain, confusion, and hallucinations after a weekend of heavy drinking. His girlfriend mentions that he has been complaining of a rapid heart rate and insomnia since the episode began. Which of the following is the most likely diagnosis?

Question 2 of 5

3. During a biochemistry lecture on heme synthesis, a medical student learns that the regulation of this pathway primarily involves the first step, which is the condensation of glycine and succinyl-CoA to form delta-aminolevulinic acid (ALA). Which of the following enzymes catalyzes this rate-limiting step?

Question 3 of 5

4. A 40-year-old man presents with a 1-year history of skin fragility and blistering on his hands. He also reports brownish discoloration of his teeth and urine that appears reddish in color. Genetic testing reveals a mutation affecting the synthesis of heme. Which of the following porphyrins is most likely accumulating in this patient's skin, leading to photosensitivity?

Question 4 of 5

5. A research scientist is studying a family with a history of a rare porphyria that manifests with both cutaneous and acute neurovisceral symptoms. The family history suggests an autosomal dominant pattern of inheritance. Laboratory studies in affected family members show increased levels of both porphobilinogen and coproporphyrin in the urine. Which of the following enzymes is most likely deficient in this family?

Question 5 of 5


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