My 14 month old daughter has had two stomach viruses and she awakened the next day very lethargic. We discovered that her blood sugar was 35 mg/dl [1.9 mmol/L]. We have fasted her in the hospital, and her blood sugar went down to 55 mg/dl [3.1mmol/L], but bounced back up to 70 mg/dl [3.9 mmol/L] on its own. The doctors called it ketotic hypoglycemia, but one doctor said that a “de-branching enzyme disorder is possible.” She doesn’t have an enlarged liver, and she only has this problem after prolonged fasting and sickness. How likely is this rare metabolic disorder? How would it be treated and is it life threatening? (She is exactly at 50% on both the height and weight charts.)

Many small children, when they are deprived of carbohydrate, usually because of diminished appetite during an infection, will develop low blood sugar levels. At the same time, they start to depend on fat metabolism for essential energy needs. Hence, the ketones ketones in the urine. I am quite sure that this is what is happening with your daughter, especially because she only seems to have this problem when she is sick.

Very, very uncommonly, ketotic hypoglycemia can occur with disorders of organic acid and fatty acid metabolism. It is reassuring that there is a pediatrician at hand who is familiar with these rarities.

Branched chain ketoaciduria is due to an autosomal recessive condition in which the enzyme for decarboxylation of the ketoacids of leucine,isoleucine and valine is missing. There is an unusual odor to the urine as a result of which the earlier name was maple syrup urine disease. Sometimes it can be treated by giving the vitamin thiamine in large doses, but most often it depends on a special diet that is low in these essential amino acids. There is a mild form, but with experienced care these children do well.

DOB