A 28-year-old woman comes to the physician because she has had intermittent episodes of headache, nausea, abdominal pain, and tingling of her fingers. She also complains of dark urine during the episodes. Her mother and maternal uncle have similar symptoms and her father is healthy. Laboratory tests show normal liver function tests. Intravenous dextrose is administered and her symptoms improve significantly. Dextrose infusion most likely improved this patient's condition by affecting which of the following pathways?

Question

A 28-year-old woman comes to the physician because she has had intermittent episodes of headache, nausea, abdominal pain, and tingling of her fingers. She also complains of dark urine during the episodes. Her mother and maternal uncle have similar symptoms and her father is healthy. Laboratory tests show normal liver function tests. Intravenous dextrose is administered and her symptoms improve significantly.  Dextrose infusion most likely improved this patient's condition by affecting which of the following pathways?

Quizplus · Accepted Answer

Eductional Objective: Acute intermittent porphyria is an autosomal dominant condition caused by porphobilinogen deaminase deficiency.  Most patients remain asymptomatic, but a minority present with acute attacks characterized by abdominal pain and vomiting, peripheral neuropathy, neuropsychological symptoms, and reddish-brown urine.  Treatment consists of intravenous glucose or heme preparations, which downregulate ALA synthase activity.

A 28-Year-Old Woman Comes to the Physician Because She Has