Fabry disease is a rare, inherited disorder caused by a mutation in the GLA gene on the X chromosome. This mutation leads to a deficiency of the enzyme alpha-galactosidase A, which prevents the breakdown of a complex substance called globotriaosylceramide. As a result, this substance accumulates in cells, causing abnormalities in the nerves, kidneys, heart, and eyes.

Fabry disease is often described as a "chameleon" because its symptoms vary widely depending on the patient's age. The severity and progression of symptoms also differ significantly between men and women.

Men with Fabry disease typically develop symptoms at a younger age and experience more severe progression. In most cases, symptoms in males become apparent during childhood, usually around age six or seven. In contrast, female patients often begin to show symptoms later, usually in upper elementary or middle school, and tend to experience a slower disease progression.

The first symptoms of Fabry disease often include pain in the hands and feet and abnormal sweating. The buildup of globotriaosylceramide in the body disrupts the autonomic nervous system, significantly reducing sweating and impairing the body's ability to regulate temperature. Patients frequently experience intense, paroxysmal pain in the hands and feet—pain that is often misunderstood as psychosomatic, since standard medical tests fail to detect it. Over time, Fabry disease leads to clear physical abnormalities.

The condition affects multiple organs: it damages the kidneys, leading to proteinuria, and causes the heart to enlarge and function poorly, resulting in myocardial hypertrophy, infarction, and arrhythmias. Fabry disease is a textbook example of a rare illness often diagnosed only after irreversible organ damage and a long, frustrating search for answers.

This was the case for 59-year-old Jang Dong-ki, president of Fabry Korea, who was diagnosed in 2017 -- more than 40 years after his symptoms first appeared. Jang, who has a less severe deficiency of the alpha-galactosidase A enzyme, began showing symptoms as a high school freshman.

"My hands were very numb. The slightest breeze would cause pain like a knife cut, and when the pain was severe, I wanted to die. But because there were no visible symptoms, everyone thought I was a ‘malingerer,’" he recalls.

Another troubling symptom was his inability to sweat.

“Others would sweat heavily in the summer, but I wouldn’t sweat at all. My face would turn red and feverish, and I always felt overheated. I even took cold showers in the winter because I felt so hot,” Jang said.

In 2004, a routine medical checkup revealed he had an enlarged heart. He received treatment at Incheon Medical Center, where he lived, and later at Inha University Hospital—but no specific cause was identified. His mother also had an enlarged heart, so he assumed it was hereditary.

In 2017, the year Jang was diagnosed with Fabry disease, a significant event happened. He was playing golf in Suwon when he suddenly lost consciousness and collapsed. He was rushed to Aju University Hospital, where he regained consciousness. Still, the doctors told him that the EKG showed that there was something wrong with his heart that couldn't be explained by myocardial hypertrophy alone, but they couldn't find the cause. No longer able to ignore the cause of his body's painful problems, Jang went to Severance Hospital, where he was diagnosed with arrhythmia and underwent a series of procedures.

The first arrhythmia procedure didn't work for him. Neither did the second. His cardiologist referred him to Professor Hong Geu-ru, a Fabry disease specialist in the same department. After reviewing his medical history, Professor Hong explained that he would draw blood and send it overseas for genetic testing. The results would be available in 45 days at the earliest and 60 days at the latest. It was 45 days later when Jang received a call from Severance Hospital.

He received the call on a Thursday, but Tuesday was the earliest he could make time for a doctor's appointment as a small business owner. That morning, he was the first patient in the clinic, and Professor Hong diagnosed him with Fabry disease. At the age of 50, he had finally found the cause of a condition that had plagued him since high school, sometimes making him feel like he wanted to die. After the diagnosis, he began treatment, taking medication every other day, and slowly began to feel free of the things that had been bothering him.

"I take a medicine that maintains my enzyme (globotriaosylceramide), and the treatment results are excellent. I like to play sports, but before the treatment, I couldn't play table tennis because I was too short of breath. Now I feel good enough to play table tennis. I also sweat a little now. The most important thing is that I don't have severe pain anymore," he said, adding that being correctly diagnosed and treated has made an enormous difference to his quality of life.

Knowing from experience the importance of early diagnosis and treatment of Fabry disease, he started by searching for patients in his family, which led to the discovery of nearly 10 patients. Since becoming president of Fabry Korea in April 2023, finding patients has been his primary focus. Because it is a genetic disease, once you find one patient, you can find many patients in the family, like digging for sweet potatoes. Still, he knows from experience that there is strong resistance from the family, so he created a family testing support system within the patient association. Through this, they found nine patients last year alone.

The landscape of Fabry disease diagnosis has also changed. Since January of last year, Fabry disease has been included in the newborn screening list, allowing for early diagnosis within the national system. Awareness of Fabry disease has definitely increased as the patient association, medical professionals, and pharmaceutical companies have been working hard to publicize the disease. 

As the diagnosis problem has been solved to a certain extent, Fabry disease has a bigger problem. Even with early diagnosis, treating Fabry disease ‘early’ is difficult.

This is due to the Korean health insurance reimbursement standards for Fabry disease treatments, which currently do not allow patients to start treatment as soon as they are diagnosed with Fabry disease. 

For example, in the case of myocardial hypertrophy caused by Fabry disease, the thickness of the left ventricle (normal 7~8 millimeters) must exceed 12㎜ before the patient can start “reimbursed treatment,” where only 10 percent of the treatment is paid by the patient. If the patient is already hypertrophied and has a left ventricular thickness of 10 mm when diagnosed with Fabry disease, the patient must pay 100 percent of the cost of the medication.

Because Fabry disease medications are expensive and require a lifetime of use, it is not easy for patients and families to start treatment if they are not covered by insurance. In addition, foreign countries have a system that allows patients to start treatment as soon as a problem is detected, which is not the case in Korea, and medical professionals specializing in Fabry disease have pointed out that this needs to be improved. The same is true for people with Fabry disease, who suffer irreversible damage from the current system of reimbursement for Fabry disease drugs.

"We should be able to start enzyme infusion treatment at the discretion of a Fabry disease specialist," Jang said.  "This year, we sent a proposal to the Health Insurance Review and Assessment Service (HIRA) to create an environment where early treatment for Fabry disease is possible, and we will continue to voice our opinions on this issue. We hope this will change Fabry disease's status to an environment where early treatment is possible."