ABGC Boards Prep Metabolic Genetics
Questions and Answers
Question: A newborn presents with lethargy and vomiting. Further studies show she has
low ketones and low blood sugar. What laboratory tests would you want to order to try
to pin down a diagnosis? - ANSWER-Answer: plasma acylcarnitine
(This question assumes newborn screen was not completed/did not pick up a problem).
Question: A newborn presents with lethargy and vomiting. Further testing shows she
has metabolic acidosis with an anion gap. What laboratory tests would you want to
order to try to pin down a diagnosis? - ANSWER-Answer: urine organic acid test (could
also do plasma acylcarnitine)
(This question assumes newborn screen was not completed/did not pick up a problem).
Question: A newborn presents with lethargy and vomiting. Her acylcarnitine profile is
normal, and her urine organic acid levels are normal. She is found to have
hyperammonemia. What type of disorder are you suspecting now? - ANSWER-Answer:
Urea cycle disorder
Question: A newborn presents with lethargy and vomiting. Her acylcarnitine profile is
normal, and her urine organic acid levels are normal. What laboratory tests would you
want to order next to try to pin down a diagnosis? - ANSWER-Answer: Plasma amino
acids, Urine orotic acids, look for hyperammonemia
Question: A patient is newly diagnosed with a fatty acid oxidation disorder.
1) How would she be initially treated?
2) What would her long-term management recommendations be? - ANSWER-Answer:
1) Dextrose, early use of fluids to prevent hypoglycemia
2) Low fat diet, avoid prolonged fasting, nighttime feeds when sick, supplement with
carnitine.
Specifically for long-chain disorders (LCAD): Recommend followup with cardiology
Question: A patient is newly diagnosed with an organic acid disorder.
1) How would she be initially treated?
2) What would her long-term management recommendations be? - ANSWER-Answer:
1) Short term treatment:
Dextrose, early use of fluids, no protein or fat (until they figure out the diagnosis), IV
lipid emulsion, potentially dialysis if neonate is sick
(dialysis d/t toxicity in kidneys)
Questions and Answers
Question: A newborn presents with lethargy and vomiting. Further studies show she has
low ketones and low blood sugar. What laboratory tests would you want to order to try
to pin down a diagnosis? - ANSWER-Answer: plasma acylcarnitine
(This question assumes newborn screen was not completed/did not pick up a problem).
Question: A newborn presents with lethargy and vomiting. Further testing shows she
has metabolic acidosis with an anion gap. What laboratory tests would you want to
order to try to pin down a diagnosis? - ANSWER-Answer: urine organic acid test (could
also do plasma acylcarnitine)
(This question assumes newborn screen was not completed/did not pick up a problem).
Question: A newborn presents with lethargy and vomiting. Her acylcarnitine profile is
normal, and her urine organic acid levels are normal. She is found to have
hyperammonemia. What type of disorder are you suspecting now? - ANSWER-Answer:
Urea cycle disorder
Question: A newborn presents with lethargy and vomiting. Her acylcarnitine profile is
normal, and her urine organic acid levels are normal. What laboratory tests would you
want to order next to try to pin down a diagnosis? - ANSWER-Answer: Plasma amino
acids, Urine orotic acids, look for hyperammonemia
Question: A patient is newly diagnosed with a fatty acid oxidation disorder.
1) How would she be initially treated?
2) What would her long-term management recommendations be? - ANSWER-Answer:
1) Dextrose, early use of fluids to prevent hypoglycemia
2) Low fat diet, avoid prolonged fasting, nighttime feeds when sick, supplement with
carnitine.
Specifically for long-chain disorders (LCAD): Recommend followup with cardiology
Question: A patient is newly diagnosed with an organic acid disorder.
1) How would she be initially treated?
2) What would her long-term management recommendations be? - ANSWER-Answer:
1) Short term treatment:
Dextrose, early use of fluids, no protein or fat (until they figure out the diagnosis), IV
lipid emulsion, potentially dialysis if neonate is sick
(dialysis d/t toxicity in kidneys)
