Differential Diagnosis
- Single most likely diagnosis
- Glycogen debrancher (Cori's disease): The patient's presentation of poor feeding, irritability, hypotonia, muscle wasting, hepatomegaly, low serum glucose, and elevated urine ketone bodies is consistent with a glycogen storage disorder. The normal lactic acid level and elevated ketone bodies suggest a problem with glycogen breakdown, which is consistent with glycogen debrancher deficiency.
- Other Likely diagnoses
- Acid alpha-glucosidase (Pompe disease): This enzyme deficiency leads to glycogen accumulation in muscles, causing hypotonia, muscle wasting, and cardiomegaly. However, the absence of cardiopulmonary abnormalities makes this less likely.
- Glucose-6-phosphatase (Von Gierke's disease): This deficiency causes hypoglycemia, hepatomegaly, and elevated ketone bodies, but typically presents with lactic acidosis, which is not seen in this patient.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Muscle phosphorylase (McArdle's disease): Although this disease typically presents later in life, it can cause hypoglycemia, muscle weakness, and elevated creatine kinase. Missing this diagnosis could lead to delayed treatment and worsening of symptoms.
- Rare diagnoses
- Glucocerebrosidase (Gaucher's disease): This enzyme deficiency leads to lysosomal storage disease, causing hepatomegaly, splenomegaly, and bone marrow involvement. However, the patient's presentation is not typical for Gaucher's disease, making it a less likely diagnosis.
- Other glycogen storage diseases: There are several other glycogen storage diseases, such as glycogen brancher deficiency (Andersen's disease) or glycogen synthase deficiency, that could present with similar symptoms. However, these are rare and would require further testing to diagnose.