Transthyretin amyloidosis, also known as ATTR amyloidosis, is a rare and often misdiagnosed disease that occurs when abnormal protein deposits called amyloids build up in various organs throughout the body, including the heart, kidneys, and nervous system. This can lead to a range of symptoms and complications that can severely impact the patient’s quality of life.

Symptoms

The symptoms of ATTR amyloidosis can vary widely depending on which organs are affected. Some common early symptoms include:.

Fatigue
Dizziness or lightheadedness
Numbness or tingling in the hands or feet
Difficulty breathing
Swelling of the legs, ankles, and feet
Changes in bowel or bladder function

As the disease progresses, it can cause more severe symptoms such as:.

Heart failure
Kidney damage
Nerve damage
Dementia
Disorders of the digestive system

Causes

ATTR amyloidosis is caused by mutations in the transthyretin gene, which provides instructions for producing a protein that carries thyroid hormone and vitamin A in the blood.

Normally, transthyretin is a stable and soluble protein that does not accumulate in the body. However, certain mutations can cause the protein to become unstable and form clumps known as amyloid fibrils.

There are two main types of ATTR amyloidosis:.

Hereditary ATTR amyloidosis: This form of the disease is caused by inherited mutations in the transthyretin gene. It typically presents in middle age and progresses slowly over many years.
Wild-type ATTR amyloidosis: This form of the disease is caused by the normal aging process, which can cause the transthyretin protein to become unstable and form amyloid fibrils. It typically affects older adults and progresses more rapidly than the hereditary form.

Diagnosis

Diagnosing ATTR amyloidosis can be challenging, as the symptoms can be similar to those of other conditions and there is no single definitive test for the disease. Some common diagnostic tests include:.

Biopsy: A small sample of tissue is collected from an affected organ and examined under a microscope for the presence of amyloid deposits.
Blood tests: Blood tests can measure the levels of transthyretin and other proteins in the blood. Abnormal levels may suggest the presence of amyloidosis.
Cardiac imaging: Imaging tests such as echocardiography or cardiac MRI can show signs of amyloidosis in the heart.

Treatment

Treating ATTR amyloidosis depends on the severity of the symptoms and which organs are affected. Some common treatments include:.

Tafamidis: This medication can stabilize the transthyretin protein and reduce the formation of amyloid fibrils.
Liver transplant: As the transthyretin protein is produced in the liver, a liver transplant can replace the mutated protein with a healthy one and stop the progression of the disease.
Symptomatic treatment: Medications can be used to control symptoms such as heart failure, kidney damage, and nerve dysfunction.

Prognosis

The prognosis for ATTR amyloidosis depends on a variety of factors, including the age of onset, the severity of symptoms, and which organs are affected.

While there is currently no cure for the disease, early diagnosis and treatment can improve outcomes and quality of life for patients.