There is a rare, inherited disorder that causes excessive copper buildup in the liver. Its name is Wilson's disease -- an autosomal recessive genetic disorder that has a 25 percent chance of being passed on to children if both parents are carriers of a mutation in the ATP7B gene, even if neither parent has the disease.

"The ATP7B gene is a transporter that delivers copper, mainly in the liver. So, when copper comes into the liver, ATP7B drags it around and gives it to proteins that need copper. If there is a lot of copper, it sends it to the bile," said Professor Lee Beom-hee of the Department of Medical Genetics at Asan Medical Center in Seoul, explaining Wilson's disease on the YouTube channel "Medical Library.”

When it fails, copper comes into the liver, but it cannot be removed, Professor Lee added.

Sometimes, it takes the form of myasthenia gravis or hemolytic anemia

Wilson's disease is one of the most common rare autosomal recessive genetic disorders, with an incidence of one in 30,000 people. "It is estimated that there are thousands of patients with Wilson's disease in Korea," Professor Lee said. "Wilson's disease gene carriers are more common in East Asians, with one in 50 to 100, and rare in Caucasians."

Currently, Wilson's disease is a rare genetic disorder not screened by newborn screening tests. People are at risk of Wilson’s disease when their blood levels of ceruloplasmin, a protein that attracts copper, are low. Because newborns naturally have low levels of this protein, it isn't easy to diagnose accurately. Genetic testing is increasingly used when Wilson's disease is suspected.

Wilson's disease is usually discovered by accident.

"It's most often found when babies come into the hospital with a cold or pneumonia, and their liver somatic indexes are too high and don't go down, so doctors look for the cause," Lee said. "If it’s diagnosed when children are about four or five years old, it belongs to early diagnosis. In other cases, it's found when the liver breaks down and becomes cirrhotic."

Wilson's disease is sometimes diagnosed in adulthood, and adults are at a higher risk of being diagnosed later.

"Most adults are treated for hepatitis when their liver levels are elevated," Lee said, adding that there are cases where people are told they need to cut down on alcohol and are diagnosed late.

Not everyone with Wilson's disease shows high liver somatic indexes enough to suspect hepatitis.

"In some cases, the liver levels aren't that high, but it manifests as neurological symptoms," Lee said. "Some in their 20s or 30s who used to have a normal social life may have a slight tremor in their hands. Soon, their hands get stiff, they can't pronounce or swallow saliva, their arms are stiff, and they have some dystonia. In rare cases, Wilson's disease may be discovered incidentally while performing tests for hemolytic anemia."

The level of ceruloplasmin is measured to identify Wilson's disease. Still, it is not measured in routine blood tests in hospitals, which means that this test can only be performed if Wilson's disease is suspected, and only then can Wilson's disease be diagnosed. "If you have liver levels that are too high or unexplained for viral hepatitis, you should suspect Wilson's disease and get a test to measure ceruloplasmin," Lee said.

If diagnosed late, Wilson's disease may be detected in a patient with jaundice due to cirrhosis of the liver. In children, Wilson's disease is sometimes diagnosed in conjunction with fulminant hepatitis. "You can have Wilson's disease and then have a viral infection, and it gets really bad," Lee said. "Sometimes it's almost found as liver failure. So there are cases in children where Wilson's disease can be very life-threatening."

Moreover, if Wilson's disease is detected too late, the symptoms are not easily reversible, even with treatment. "The neurological symptoms don't come back well even with treatment,” Lee said. "In addition, if the liver is cirrhotic to the point of cirrhosis, some of it comes back when the copper is removed, and some patients are managed with medication for decades. If it progresses, then we do a liver transplant."

Copper-restricted diets and copper excretion/absorption modifiers are treatments

Wilson's disease is treated with a copper-restricted diet and medications that prevent copper from being excreted or absorbed by the body. Treatment usually involves avoiding foods high in copper, such as chocolate, nuts, liver, mushrooms, and medication. There are two main types of medications.

"One is penicillamine, which excretes copper from the body in the urine, but there is a risk of bone marrow suppression and proteinuria, so it is used to monitor these things, and some patients are stable for decades," Lee said. “There are other drugs that work similarly to penicillamine with slightly fewer side effects. It's called trientine, which works by flushing copper out of the liver into the urine.”

The other option is to take a zinc drug, which prevents copper from being absorbed in the intestines, which means it binds to copper in the intestines and prevents it from entering the body at all, Professor Lee added.

Of these three drugs, the one that works best for individual patients is being prescribed.

"If there are neurological symptoms, there are reports that penicillamine or trientine can make the neurological symptoms a little worse, so these patients are on medications with zinc," Lee said, explaining the medication. "Usually, the medication is taken on an empty stomach to prepare the intestines, and then the food is eaten."

Not all of Wilson's disease patients need medication. "If a baby is deficient in copper, it can be bad for brain development, so we usually don't treat it during the two to three years of brain development," Lee said.

Nor should people with Wilson's disease cut out copper entirely.

"Although Wilson's disease is a copper accumulation disease, there are many other symptoms caused by the deficiency of copper-requiring enzymes, so copper should be given to some extent," Lee said. "Once the disease is stabilized by drug treatment, there are few big problems with eating a little copper."