What is the most likely diagnosis for a 3-4 month old infant presenting with hypoglycemia, lactic acidosis, hyperuricemia, hyperlipidemia, seizures, and a doll-like face?

The clinical features described in the question align closely with Von Gierke's disease, which is a type of glycogen storage disease caused by a deficiency of the enzyme glucose-6-phosphatase. This enzyme is vital for gluconeogenesis and glycogenolysis, meaning that without it, the body cannot effectively convert glycogen back into glucose, particularly during fasting states.

In infants, this condition typically manifests with symptoms of hypoglycemia due to an inability to maintain normal blood sugar levels. The accumulation of glucose-6-phosphate (the substrate that cannot be processed because of the enzyme deficiency) leads not only to hypoglycemia but also to lactic acidosis as a result of increased conversion to lactate. The infant may also present with hyperuricemia and hyperlipidemia due to increased glycolysis and subsequent lipogenesis as the body tries to compensate for low glucose levels.

The "doll-like face" noted in the presentation is a characteristic cosmetic symptom of Von Gierke's disease, which refers to a flat, round face often associated with the condition due to subcutaneous fat deposition.

In contrast, other options such as Phenylketonuria primarily lead to intellectual disability and developmental delays due to phenylalanine