A 26-year-old man presents with new-onset confusion, tremor, and “clumsiness” for the last 3 to 4 weeks. He decided to come in after he could not remember the name of his long-term girlfriend. He has no significant past medical history and denies alcohol or illicit drug use. Physical examination shows stable vital signs and hepatomegaly. Laboratory studies reveal the following:
Which of the following is the next best step in the diagnostic workup for this patient?
A. Liver biopsySerum ceruloplasmin levels. The patient in this question is presenting with neuropsychiatric symptoms and hepatomegaly consistent with a likely diagnosis of Wilson disease. Wilson disease is an autosomal recessive disorder in which copper accumulates in tissues due to mutations in the Wilson disease protein (ATP7B) gene; this causes a defect in incorporation of copper in hepatic lysosomes. Clinical symptoms range from an asymptomatic state to tremor, depression, and memory impairment. The diagnosis is confirmed by low serum ceruloplasmin levels (normally <20 mg/dL), increased urinary copper, and Kayser–Fleischer rings (so a slit lamp examination of the eye should also be performed). (A) Liver biopsy in Wilson disease often shows inflammation, portal fibrosis, and necrotic hepatocytes. Macrovesicular steatosis and Mallory bodies may also be present. A less invasive test (such as a blood test) should be ordered before a liver biopsy is performed. (B) α-1 antitrypsin levels would be ordered if α-1 antitrypsin deficiency were suspected, but this disease is associated with liver and lung (emphysema in young patients) disease. (C) Lumbar puncture (LP) for CSF analysis is not useful in Wilson disease. Even though the neurologic symptoms in Wilson disease are caused from copper accumulation in the basal ganglia, this would not generate positive CSF findings.