You are asked to consult on a newborn who is several days old and has persistent jaundice, vomiting, poor feeding, and failure to thrive. She was born at home to a 30 year old healthy G1P1 mother. They did undergo prenatal screening but the patient has not seen any doctors since birth. When you examine the patient, you note a jaundiced lethargic infant with hepatomegaly and hypotonia. The fontanelle is full, and there is some edema and possibly ascites. Two weeks later, lenticular cataracts are noted; if this is not caught early, patients with this disease develop a nuclear cataract where the nucleus of the lens looks like a cloud of dust. Laboratory tests in the infant show a hyperbilirubinemia, abnormal LFTs, coagulopathy, and increased levels of plasma phenylalanine, tyrosine, and methionine.
Challenge: What's a possible diagnosis?
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