My son was diagnosed with ketotic hypoglycemia when he was 11 months old. His sugars have been hard to keep up lately. He is not a big eater. His doctor recently suggested that he may have a rare metabolic disorder. Can you shed any light on what the disorder may be called? The doctor said it involved a lack of ability for the liver to process protein into sugar.

There are three groups of rare metabolic disorders that may give rise to hypoglycemia. The most common are those of carbohydrate metabolism and include the glycogen storage diseases in which the liver is enlarged and galactosemia where the infants are intolerant to milk at birth. Both of these seem very unlikely. Hereditary fructose intolerance can present with hypoglycemia; but again there are always other physical signs. Primary lactic acidemia can present at any age and there are many causes for it. The second group includes disorders of fatty acid oxidation and carnitine; but again these usually present much earlier and with an array of symptoms. The last group are the disorders of organic acids like methyl malonic aciduria.

If your doctor is really convinced that the hypoglycemia is not manageable by simple means you might think to talk to him about a referral to a pediatric metabolic center, because as you have probably gathered, the diagnosis of these rare conditions can be complex.

DOB