A 2-month-old boy is evaluated for failure to thrive. As the pediatrician examined the child, she witnesses a seizure. Physical examination is remarkable for hepatomegaly, a finding later confirmed by CT scan, which also reveals renomegaly. Serum chemistries demonstrate severe hypoglycemia, hyperlipidemia, lactic acidosis, and ketosis. Which of the following diseases best accounts for this presentation?

Von Gierke's disease is a glycogen storage disease caused by a deficiency of glucose-6-phosphatase. It typically presents with neonatal hypoglycemia, hyperlipidemia, lactic acidosis, and ketosis. Failure to thrive is common in early life; convulsions may occur due to profound hypoglycemia. The glycogen accumulation in von Gierke's disease occurs primarily in the liver and kidneys, accounting for the enlargement of these organs. Gout may develop later because of the derangement of glucose metabolism. Even if you do not remember all of the details of the presentation of these genetic diseases, you should be able to narrow the choices: Gaucher's disease and Niemann-Pick disease are lipid storage diseases, and would not be expected to produce hypoglycemia. The other diseases are glycogen storage diseases, but McArdle's and Pompe's disease affect muscle rather than liver and would not be expected to produce profound hypoglycemia, since the liver is the major source for blood glucose.