Testing

 Test Which of the following could also appear as a peak on this patient’s lab value chart? A) Phenyllactate B) Orotic Acid C) Oxidized Tetrahydrofolate D) Homocysteine E) Epinephrine Explanation Explanation: The correct answer is Choice D: Homocysteine. This patient has methylmalonic acidemia, indicative of a cobalamin/B12 deficiency. Other symptoms that prove this diagnosis are severely low hemoglobin (indicative of anemia, specifically macrocytic), encephalopathy (attributable to the patient’s secondary hyperammonemia, which is resultant of organic acids like MMA inhibiting NAG Synthase which causes an increase in free ammonia from lack of CPSI stimulation). The ataxia is attributable to neurological abnormalities due to deficiency of S-adenosylmethionine for neurotransmitter synthesis. There is therefore less epinephrine,...