Heart disease is usually caused by genetics or high blood pressure, but there is also a rare disease that can cause cardiovascular problems, which is “amyloidosis”. Amyloidosis causes abnormal amyloid protein to be deposited in the heart, leading to heart diseases such as arrhythmia, heart failure, and myocardial hypertrophy. This article takes you through the symptoms and treatment of amyloidosis.

What is amyloidosis?

Amyloidosis (amyloidosis), the full name of which is “Familial Amyloidotic Polyneuropathy (FAP)”, is a chromosomally dominant genetic disease caused by mutations in the transthyretin gene, resulting in abnormal amyloid protein. (amyloid) accumulates in the meninges, heart, eyes, lungs, and gastrointestinal system, affecting the peripheral nerves and autonomic nervous system, and the human body cannot metabolize it on its own.

It is worth noting that as long as one person in the family has this disease, there is a 50% chance that the remaining offspring will also inherit it. The onset age of men is about 55 years old and that of women is about 65 years old. For patients, the peripheral nerves and heart are mainly affected.

Early symptoms of amyloidosis are not obvious

Because autonomic nerves are present throughout the body, symptoms are sometimes difficult to detect, which is why diagnosis of amyloidosis is often delayed. It is most often misdiagnosed as a gastrointestinal symptom. Patients with persistent abdominal pain and diarrhea are usually diagnosed as irritable bowel syndrome. Only when symptoms of limb weakness or sensory nerves appear, amyloidosis is found to be at work. The symptoms of amyloidosis can be roughly divided into sensory nervous system and autonomic nervous system:

1. Sensory nervous system: numbness and sluggishness in the limbs, movement disorders, tingling or electric shock sensation.
   
2. Autonomic nervous system: diarrhea, constipation, sexual dysfunction, dizziness, vomiting, perspiration disorder

However, the above two cannot be accurately judged as symptoms of amyloidosis. National Taiwan University Hospital also lists different symptoms according to the location of amyloid deposition:

1. Kidney: proteinuria, nephropathy.
   
2. Heart: arrhythmia, myocardial hypertrophy, congestive heart failure.
   
3. Liver: chronic hepatitis, cirrhosis.
   
4. Muscles: Unable to walk or stand.
   
5. Eyes: dry eye, glaucoma, lens opacity.

If people find that they always have tingling and numbness in their limbs, combined with the above symptoms, and cannot find out what the disease is, it is recommended to go to the neurology department of the hospital for diagnosis as soon as possible.

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Can amyloidosis be cured?

Amyloid-like proteins are deposited in organs, causing them to continue to degenerate. Taiwan Pharmaceutical Information points out that the average survival time of patients after the onset of the disease is about 13 months, and the average survival rate for more than 10 years after the onset of the disease is less than 5%. You may be wondering, can this rare genetic disease be treated? In fact, it is possible, but the treatment process is relatively difficult. There are currently two treatment methods:

1. Liver transplant:
   If the disease develops before the age of 50, liver transplantation can be performed and the prognosis is good.
   
2. Medical treatement:
   Medication treatments can be divided into the following 4 types:
   
   • Diflunisal:
     Allows protein metabolism to stabilize and prevent abnormal deposition in organs. Renal function must be monitored before use. Patients with renal function problems or congestive heart failure are not suitable to use this drug.
     
   • Tafamidis meglumine:
     Stabilizes protein metabolism and prevents abnormal deposition in organs. Common side effects include diarrhea, abdominal pain, and urinary tract infection.
     
   • RNAi: The effect is more significant than oral drugs. This drug is injected intravenously, which will inhibit the production of liver and reduce the amount of transthyretin secreted. However, injecting this drug can cause vitamin A deficiency, dizziness, vomiting, and facial flushing. It is recommended to supplement more vitamin A during treatment.
     
   • Inotersen:
     It is a drug injected subcutaneously, and its therapeutic effect is not far from that of RNAi. It is necessary to monitor the platelet count before injecting the drug, because this drug can cause low platelets and vitamin A deficiency.