Wilson’s Disease – Risk factors, Symptoms and Diagnosis.

Definition

Wilson’s disease is an inherited disorder in which excessive amounts of copper accumulate in the body, particularly in the liver, brain, and eyes. The signs and symptoms of Wilson disease usually first appear between the ages of 6 and 45, but they most often begin during the teenage years. The features of this condition include a combination of liver disease and neurological and psychiatric problems.

Wilson’s disease effects

History

The disease bears the name of the British physician Samuel Alexander Kinnier Wilson (1878–1937), a neurologist who described the condition, including the pathological changes in the brain and liver, in 1912. Wilson’s work had been predated by, and drew on, reports from German neurologist Carl Westphal (in 1883), who termed it “pseudosclerosis”; by the British neurologist William Gowers (in 1888); and by Adolph Strümpell (in 1898), who noted hepatic cirrhosis. Neuropathologist John Nathaniel Cumings made the link with copper accumulation in both the liver and the brain in 1948. The occurrence of hemolysis was noted in 1967.

Cumings, and simultaneously the New Zealand neurologist Derek Denny-Brown, working in the United States, first reported effective treatment with metal chelator British anti-lewisite in 1951. This treatment had to be injected but was one of the first therapies available in the field of neurology, a field that classically was able to observe and diagnose but had few treatments to offer. The first effective oral chelation agent, penicillamine, was discovered in 1956 by British neurologist John Walshe. In 1982, Walshe also introduced trientine,  and was the first to develop tetrathiomolybdate for clinical use. Zinc acetate therapy initially made its appearance in the Netherlands, where physicians Schouwink and Hoogenraad used it in 1961 and in the 1970s, respectively, but it was further developed later by Brewer and colleagues at the University of Michigan. The genetic basis of Wilson’s disease and linkage to ATP7B mutations was elucidated in the 1980s and 1990s by several research groups.

Epidemiology

Wilson disease is found worldwide, with an estimated prevalence of 1 case per 30,000 live births in most populations. More recent data from population screening by molecular sequencing in the United Kingdom suggest a potentially higher prevalence, perhaps as frequent as 1 case in 702. Assuming a prevalence of 1 in 10,000 to 30,000, approximately 1 person in 90 carries an abnormal copy of the ATP7B gene. However, in some isolated populations, the prevalence is much higher. One of the highest reported prevalences was from a small mountain village on the island of Crete, where Wilson disease was diagnosed in 1 in 15 births. The increased prevalence was likely due to high rates of consanguinity in the isolated area.

Risk factors

Risk factors for Wilson’s disease are genetic. Parents who carry the gene are at risk for passing the disease on to their children. A genetic test can be performed if a child shows symptoms of Wilson’s and has one or both parents who have the disease.

Causes of wilson’s disease

The cause of Wilson’s disease is genetic. The disease follows an autosomal recessive inheritance pattern. This means both parents either have the disease or are a carrier of the gene. This is the only way it can be passed on to their children. Wilson’s disease is caused by a mutation in the ATP7B gene that prevents the liver from disposing of copper as a healthy liver should.

Symptoms of wilson’s disease

The symptoms are usually dependant on where more of the copper is deposited, which is the abnormality in Wilson’s disease. The copper primarily accumulates in the liver, brain and also eyes. So depending on which organ is affected, the symptoms vary.

If copper deposits in the brain, then symptoms includes:

• Change in handwriting, which is seen as an early sign usually in the child or young adult.
• Deterioration in academic performance of the child, who used to score well earlier
• Slurred speech
• Drooling of saliva
• Difficulty in walking
• Difficulty in swallowing
• Tremors
• Contractures (a condition in which the muscles of the hands and legs harden leading to the rigidity of joints). In such a case, the legs and hands remain in one position and the person may not be able to straighten it.
• Lastly, the patients become bed ridden.

If copper deposits in the liver, then the signs that might indicate Wilson’s disease include:

• Jaundice: Although there are many causes of jaundice, one should suspect Wilson’s disease if jaundice in young patients lasts for long (say for a month or two). Also if a kid has recurrent jaundice, then it is a sign that the liver is in trouble due to copper accumulation. Here’s more on symptoms of jaundice.
• Abnormal liver function test
• Cirrhosisin young adults or child
• Acute liver failure with major dropping haemoglobin in young patients (5 years to 15 years, although according to books it is anyone between the age group of 3 – 55 years) indicates Wilson’s disease.

Other symptoms like fatigue, lack of appetite, swelling of the feet, fluid accumulation in the abdomen, distention of the abdomen, black stools, blood vomit-are some of the general symptoms of liver disease, which are not specific of Wilson’s disease.

If copper gets deposited in the eyes, it results in Kayser-Fleischer rings, which are rusty brown coloured rings surrounding the edge of the iris and in the rime of the cornea. This is one of the unique symptoms of Wilson’s disease, which is usually detected during an eye examination. Read more on what your eyes say about your health.

Diagnosis and tests

Diagnosing Wilson’s disease can be challenging because its signs and symptoms are often indistinguishable from those of other liver diseases, such as hepatitis. What’s more, many symptoms may evolve over time rather than appear all at once. Behavioral changes that come on gradually can be especially hard to link to Wilson’s. Doctors rely on a combination of symptoms and test results to make the diagnosis.

Tests and procedures used to diagnose Wilson’s disease include:

• Blood and urine tests.Your doctor may recommend blood tests to monitor your liver function and check the copper levels in your blood. Your doctor also may want to measure the amount of copper excreted in your urine during a 24-hour time period.
• Eye exam.Using a microscope with a high-intensity light source (slit lamp), an ophthalmologist checks your eyes for golden-brown discoloring (Kayser-Fleischer rings). The abnormal appearance is caused by deposits of excess copper in the eyes. Wilson’s disease has also been associated with a type of cataract, called a sunflower cataract that can be seen on an eye exam.
• Removing a sample of liver tissue for testing.In a procedure called a liver biopsy, your doctor inserts a thin needle through your skin and into your liver. Your doctor draws out a small sample of liver tissue and sends it to a laboratory to test for excess copper.
• Genetic testing.A blood test can identify the genetic mutations that cause Wilson’s disease. Knowing the Wilson’s disease mutations in your family allows doctors to screen siblings and begin treatment before debilitating symptoms arise.                                                                                                         

Treatment and medication

Successful treatment of Wilson’s disease depends upon timing more than medication. Treatment often happens in three stages and should last a lifetime. If a person stops taking the medications, copper can build back up again.

First stage: The first treatment is to remove excess copper from your body through chelating therapy. Chelating agents include drugs like d-penicillamine and trientine, or Syprine. These drugs will remove the extra copper from your organs and release it into the bloodstream. Your kidneys will then filter the copper into the urine. Trientine has fewer reported side effects than d-penicillamine. Potential side effects d-penicillamine include:

• Fever
• Rash
• Kidney issues
• Bone marrow issues

Your doctor will provide lower dosages of chelating drugs if you’re pregnant, as they can cause birth defects.

Second stage: The goal of second stage is to maintain normal levels of copper after removal. Your doctor will prescribe zinc or tetrathiomolybdate if you’ve finished the first treatment or show no symptoms but have Wilson’s disease. Zinc taken orally as salts or acetate (Galzin) keeps the body from absorbing copper from foods. You may have slight stomach upset from taking zinc. Children with Wilson’s disease but no symptoms may want to take zinc to prevent the condition from worsening or slow its progress.

Third stage: After the symptoms improve and your copper levels are normal, you’ll want to focus on long-term maintenance therapy. This includes continuing zinc or chelating therapy and regularly monitoring your copper levels. You can also manage your copper levels by avoiding foods with high levels, such as:

• Dried fruit
• Liver
• Mushrooms
• Nuts
• Shellfish
• chocolate
• Multivitamins

You might want to check your water levels at home, too. There may be extra copper in your water if your home has copper pipes. Medications can take anywhere from four to six months to work in a person who is experiencing symptoms. If a person doesn’t respond to these treatments, they may require a liver transplant. A successful liver transplant can cure Wilson’s disease. The success rate for liver transplants is 85 percent after one year.

Prevention of wilson’s disease

Parents with Wilson disease should be counseled after marriage and go for routine test to prevent passing on the disease to sibling. Genetic test can be done and genetic mutation can be done for affected people with family history.