Differential Diagnosis for Elevated ALT in a 48-year-old Woman

Single Most Likely Diagnosis

• Fatty Liver Disease: This is the most common cause of isolated ALT elevation in an otherwise healthy individual. The low vitamin D level may also be associated with fatty liver disease, as vitamin D deficiency is common in patients with this condition.

Other Likely Diagnoses

• Viral Hepatitis: Although less common, viral hepatitis (such as hepatitis A, B, or C) can cause elevated ALT levels. The patient's relatively good health does not rule out the possibility of a viral infection.
• Medication-induced Liver Injury: Certain medications can cause liver injury, leading to elevated ALT levels. A thorough medication history is necessary to investigate this possibility.
• Autoimmune Hepatitis: This condition can cause elevated liver enzymes, including ALT, although it is less common than fatty liver disease.

Do Not Miss Diagnoses

• Wilson's Disease: Although rare, Wilson's disease is a genetic disorder that can cause liver damage and elevated ALT levels. It is essential to consider this diagnosis to avoid missing a potentially treatable condition.
• Alpha-1 Antitrypsin Deficiency: This genetic disorder can cause liver disease and elevated ALT levels. Early diagnosis is crucial to prevent long-term liver damage.
• Budd-Chiari Syndrome: This rare condition, caused by hepatic vein thrombosis, can lead to elevated liver enzymes, including ALT. It is essential to consider this diagnosis to avoid missing a potentially life-threatening condition.

Rare Diagnoses

• Hemochromatosis: A genetic disorder that can cause iron overload and liver damage, leading to elevated ALT levels.
• Glycogen Storage Diseases: Rare genetic disorders that can cause liver damage and elevated ALT levels.
• Mitochondrial Disorders: A group of rare genetic disorders that can affect the liver and cause elevated ALT levels.