Diagnosing Wilson's disease involves a combination of clinical assessments and laboratory tests to confirm the presence of excess copper accumulation in the body. Here's a breakdown of the diagnostic process:
1. Medical History and Physical Examination
- The doctor will begin by taking a detailed medical history, including any family history of liver disease, neurological symptoms, or psychiatric issues.
- A thorough physical exam will be conducted to look for signs of Wilson's disease, such as:
- Jaundice (yellowing of the skin and eyes)
- Abdominal swelling
- Neurological symptoms like tremors, difficulty with coordination, or speech problems
- Psychiatric symptoms, including personality changes, depression, or psychosis
2. Blood and Urine Tests
- Ceruloplasmin Level: This is a key test. Wilson's disease often causes low levels of ceruloplasmin, a protein that carries copper in the blood. However, normal levels do not rule out Wilson's disease, especially in younger individuals.
- Serum Copper Level: Measuring the total copper in the blood can be helpful, but it may not be as reliable as ceruloplasmin levels. In Wilson's disease, it may be low or normal.
- Liver Function Tests (LFTs): These tests assess liver health and can reveal abnormalities indicative of liver damage caused by copper accumulation. Elevated liver enzymes (AST, ALT) are common.
- 24-Hour Urine Copper Test: This test measures the amount of copper excreted in the urine over a 24-hour period. In Wilson's disease, urine copper levels are usually elevated.
3. Eye Exam (Slit-Lamp Examination)
- A slit-lamp examination by an ophthalmologist can detect Kayser-Fleischer rings, which are brownish-green rings around the cornea caused by copper deposits. These rings are a characteristic sign of Wilson's disease but aren't always present, especially in early stages or in those with liver involvement only.
4. Liver Biopsy
- A liver biopsy involves removing a small sample of liver tissue for microscopic examination and copper content measurement. This is a more invasive procedure, but it can provide valuable information about the extent of liver damage and confirm the presence of excess copper in the liver.
5. Genetic Testing
- Genetic testing can identify mutations in the ATP7B gene, which is responsible for producing a protein that helps the body eliminate copper. This test can be used to confirm the diagnosis, especially when other tests are inconclusive, and to screen family members of individuals with Wilson's disease.
Diagnostic Algorithm Considerations
It is important to note that diagnosing Wilson's disease can be challenging because its symptoms can mimic other conditions, and no single test is definitive. Doctors often use a scoring system (e.g., Leipzig score) that considers various clinical and laboratory findings to aid in diagnosis. A high index of suspicion is required, especially in patients with unexplained liver disease or neurological symptoms.
