Glycogen storage disorder-mimicking presentation of X-linked lymphoproliferative syndrome (XLP).

This case presents an infant male child who initially presented with clinical features resembling glycogen storage disease type I (GSD I), including hepatomegaly, a doll-like face and metabolic abnormalities. However, further investigations and genetic testing revealed a pathogenic mutation associated with X-linked lymphoproliferative syndrome, leading to a diagnosis of haemophagocytic lymphohistiocytosis. The patient was treated with immunosuppression and is now under consideration for stem cell transplantation.