• autossomal dominant disorder most commonly in Scandinavian and British descent due to deficiency of HMB-synthetase
• most heterozygotes are asymptomatic unless some factor increases the production of pyrogens, usually medications
• common drugs include steroids, alcohol, low calorie diets, and drugs (barbituates, sulfonamide antibiiotics, grisefulvin, and synthetic estrogens (birth-control)
• attacks of abdominal pain lasting several hours is the most common symptom and may be secondary to ileus or distension, but tenderness on exam and fever are absent
• peripheral neuropathy and muscle weakness improves over days, but may take years to return to normal
• diagnose: gold standard test measures RBC HMB-synthetase, screening test of normal PBG (porphobilinogen) level in urine rules out the condition
• treatment: narcotics, IV glucose (300g/day), and IV heme (4g/day)
   

References

MedStudy Pediatric Board Review, 1st edition