This study is an open label extension study for those who participated in the ION 682884-CS2 clinical trial for transthyretin-mediated amyloid cardiomyopathy (ATTR-CM). ATTR-CM is a disease caused by change in a protein called transthyretin (TTR) which can result in a build up of this protein in parts of the body including the heart. This build up is called an amyloid deposit, and when this occurs in the heart it can lead to a condition called cardiomyopathy. This study involves the medication eplontersen, which is considered investigational meaning it is not approved for commercial use by the Food and Drug Administration (FDA). Eplontersen is aimed at preventing production of the TTR protein to slow or reverse disease progression. Eplontersen is given as an injection under the skin in the upper arm, stomach or thigh. This study will last about 3 1/2 years and include 16 clinic visits. Study procedures include physical exams, blood work, questionnaires, hall walk tests, electrocardiograms (tracing of the heart's electrical activity), echocardiogram (ultrasound test of the heart) and taking a Vitamin A supplement.

This study is seeking participants with arrhythmogenic cardiomyopathy (ACM), also known as arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), due to a genetic abnormality known as a PKP2 variant. ARVD/C is an inherited disease where the muscle tissue in the right ventricle, one of the lower pumping chambers of the heart, dies and is replaced with scar tissue. This causes a weakened heart muscle and disrupts the heart's electrical system which can lead to heart failure and/or fatal heart rhythms. This study is looking at the safety and effectiveness of an investigational medication, meaning it is not yet approved for use by the Food and Drug Administration (FDA). The study medication is a gene therapy called LX-2020, and is designed to add new PKP2 genes to replace the faulty ones so your cells can make the correct PKP2 genes. The study medication is given via an intravenous (IV) line meaning in a vein. Participation in this study involve up to 25 visits including a hospitalization over the course of 1 year with an additional 4 years of follow up afterwards. Study related procedures include a variety of heart testing like electrocardiogram (ECG), echocardiogram, a test that records a tracing of the heart's electrical activity, Echocardiogram, (echo) a test that uses ultrasound to capture moving images of the heart, magnetic resonance imaging (MRI), a test that shows an image of the heart and surrounding structures, sample collection including blood, urine, tissue, nasal mucus, saliva and stool, liver ultrasound, questionnaires, physical exams, and at least a two night stay in the hospital. Medications to suppress (meaning weaken) the immune system, before receiving the LX2020 are also required. Risks associated with gene therapy include an immune response that may cause inflammation in the liver, heart or other organs. It may damage red blood cells, cause a low platelet count or cause the formation of small blood clots. There are also risk related to the study procedures including bleeding associated with the heart biopsy, risks related to drawing blood, risks of radiation, and loss of confidentiality. There is potential benefit and in the future, others with ACM may benefit from the knowledge gained from this study.

The purpose of this study is to collect information about patients with Arrhythmogenic right ventricular cardiomyopathy(ARVC) and about the disease. ARVC is a rare condition that affects heart muscle and causes abnormal heart rhythms (this is called "arrhythmia"). Participation in this study will take about 5 years. If your study doctor determines you are eligible and you agree to participate, you will be asked to visit the study doctor's office as part of your regular care for a screening visit and about 1 time each year for the length of the study. The majority of the data collected for this study will be part of your regular care, however study related procedures include arrhythmia monitoring, using wearable devices to measure tracing of the electrical activity of your heart, blood work, including genetic testing, and patient questionnaires

The purpose of this project is to study DNA and its connection to your health. DNA is in your blood, your saliva, and other tissues in your body. DNA is the unique instructions you are born with that tells your body how to work. By looking at DNA, you can learn information about your health, certain traits, and even your ancestral roots. DNA is also called your genetic information. DNA is mostly the same from person to person. But everyone's DNA is slightly different. We are still learning how DNA impacts health. This study will look at the DNA of many different people from many different backgrounds and compare it to information in their health records. The goal is to understand how learning about DNA can help improve health care for individuals, families, and the community.

Participants will provide a sample for DNA sequencing. Sequencing is the process of reading the letters of your DNA. This study may sequence your whole genome. Over time, you may be asked to provide additional samples for research purposes. The research team will collect health information about you from your medical record and may ask you questions about your health using surveys or other data collection method.

The purpose of this project is to study DNA and its connection to your health. DNA is in your blood, your saliva, and other tissues in your body. DNA is the unique instructions you are born with that tells your body how to work. By looking at DNA, you can learn information about your health, certain traits, and even your ancestral roots. DNA is also called your genetic information. DNA is mostly the same from person to person. But everyone's DNA is slightly different. We are still learning how DNA impacts health. This study will look at the DNA of many different people from many different backgrounds and compare it to information in their health records. The goal is to understand how learning about DNA can help improve health care for individuals, families, and the community.

Participants will provide a sample for DNA sequencing. Sequencing is the process of reading the letters of your DNA. This study may sequence your whole genome. Over time, you may be asked to provide additional samples for research purposes. The research team will collect health information about you from your medical record and may ask you questions about your health using surveys or other data collection method.

The purpose of this project is to study DNA and its connection to your health. DNA is in your blood, your saliva, and other tissues in your body. DNA is the unique instructions you are born with that tells your body how to work. By looking at DNA, you can learn information about your health, certain traits, and even your ancestral roots. DNA is also called your genetic information. DNA is mostly the same from person to person. But everyone's DNA is slightly different. We are still learning how DNA impacts health. This study will look at the DNA of many different people from many different backgrounds and compare it to information in their health records. The goal is to understand how learning about DNA can help improve health care for individuals, families, and the community.

Participants will provide a sample for DNA sequencing. Sequencing is the process of reading the letters of your DNA. This study may sequence your whole genome. Over time, you may be asked to provide additional samples for research purposes. The research team will collect health information about you from your medical record and may ask you questions about your health using surveys or other data collection method.

The purpose of this project is to study DNA and its connection to your health. DNA is in your blood, your saliva, and other tissues in your body. DNA is the unique instructions you are born with that tells your body how to work. By looking at DNA, you can learn information about your health, certain traits, and even your ancestral roots. DNA is also called your genetic information. DNA is mostly the same from person to person. But everyone's DNA is slightly different. We are still learning how DNA impacts health. This study will look at the DNA of many different people from many different backgrounds and compare it to information in their health records. The goal is to understand how learning about DNA can help improve health care for individuals, families, and the community.

Participants will provide a sample for DNA sequencing. Sequencing is the process of reading the letters of your DNA. This study may sequence your whole genome. Over time, you may be asked to provide additional samples for research purposes. The research team will collect health information about you from your medical record and may ask you questions about your health using surveys or other data collection method.