A 3-year-old girl is brought to the emergency department
after her parents had found that she had difficulty in waking this morning. She
has been ill with an upper respiratory tract infection for the past 2 days, so
has not been eating very well. She did not eat any of her dinner yesterday. Her
past medical history is significant for short stature and slow weight gain. She
is not on any medication. She is sleepy and difficult to arouse. The physical
examination findings are otherwise unremarkable. A finger-stick glucose level
is 36 mg/dL (2.0 mmol/L). Blood is drawn at the time of hypoglycemia. She is
treated with 1 g/kg of intravenous dextrose, after which she becomes alert and
talkative.
Laboratory results are shown:
Laboratory test
Result
Blood
Glucose: 32
mg/dL (1.8 mmol/L)
β-Hydroxybutyric
acid: 10 mg/dL (1720 μmol/L)
(Reference
range, fasting<4.2 mg/dL [403 μmol/L])
Fatty acids
(nonesterified): 80 mg/dL (2.8 mmol/L)
(Reference range, 17-42mg/dL
[0.60-1.49 mmol/L])
Cortisol: 8
μg/dL (772 nmol/L)
(Reference range, AM 6.2-19.4 μg/dL [171-535 nmol/L])
Growth
hormone: 14 ng/mL
(14 μg/L)
(Reference range, > 10 ng/mL [10 μg/L] with stimulation)
Lactate: 10.8
mg/dL (1.2 mmol/L) (Reference range, 4.5-20 mg/dL [0.5-2.2 mmol/L])
Toxicology
screen: Negative
Urine
Urinalysis: Large
amount of ketones present
Organic acids: Normal
Of the following, the MOST likely diagnosis is
A. Fatty acid oxidation disorder
B. Glycogen storage disease
C. Hyperinsulinism
D. Ketotic
hypoglycemia
E. Dawn phenomena
Answer on 27/03/2019
