Deciphering Familial Amyloid Polyneuropathy: The Power of Genetic Testing

Expert Reviewed By: ⁠Dr. Brandon Colby MD

Familial amyloid polyneuropathy (FAP) is a rare, inherited condition that affects the nervous system and other organs. This progressive disorder is caused by mutations in the transthyretin (TTR) gene, leading to the accumulation of abnormal amyloid proteins in tissues and organs. FAP is a heterogeneous disease, with various subtypes such as the Iowa type, which is characterized by specific symptoms and a unique genetic mutation. In this article, we will explore the importance of understanding, diagnosing, and using genetic testing for FAP, Iowa type.

Understanding Familial Amyloid Polyneuropathy

FAP is a complex disease that can manifest in different ways, depending on the specific genetic mutation and the individual’s genetic background. Some common symptoms of FAP include sensory, motor, and autonomic neuropathy, which can lead to numbness, tingling, pain, muscle weakness, and problems with the digestive system, heart, and blood vessels. The disease can also affect the eyes, kidneys, and other organs.

One of the most well-known subtypes of FAP is the Iowa type, which is caused by a specific mutation in the TTR gene. This mutation leads to a rapidly progressive form of the disease, with symptoms typically appearing in middle age and worsening over time. Patients with FAP, Iowa type, may experience significant disability and a reduced life expectancy.

Diagnosing Familial Amyloid Polyneuropathy

Diagnosing FAP can be challenging, as the symptoms can be similar to other forms of polyneuropathy. However, a combination of clinical examination, laboratory tests, and genetic testing can help to confirm the diagnosis. A recent study on genetic screening for transthyretin familial amyloid polyneuropathy highlights the importance of genetic testing in avoiding misdiagnosis in patients with polyneuropathy associated with high protein in the cerebrospinal fluid.

Genetic Testing for Familial Amyloid Polyneuropathy

Genetic testing for FAP involves analyzing the DNA of an individual to identify mutations in the TTR gene. This can be done using a blood sample or other tissue samples, depending on the specific testing method. Genetic testing can not only confirm the diagnosis of FAP but also help to identify the specific subtype of the disease, such as the Iowa type.

Preimplantation Genetic Testing for Familial Amyloid Polyneuropathy

For families with a known history of FAP, preimplantation genetic testing (PGT) can be a powerful tool to prevent the transmission of the disease to future generations. PGT involves screening embryos created through in vitro fertilization (IVF) for the presence of the TTR gene mutation before implantation. A recent article on preimplantation genetic testing for familial amyloid polyneuropathy discusses the potential of PGT to prevent and eradicate FAP, a fatal neurodegenerative disorder.

Discovering New Genetic Mutations

As our understanding of FAP continues to grow, researchers are discovering new genetic mutations that cause the disease. A recent study on a novel ATTR L32V mutation causing familial amyloid polyneuropathy in a Bolivian family highlights the importance of ongoing research in this area. Identifying new mutations can help to improve our understanding of the disease and lead to more accurate diagnoses and better treatment options for patients.

Conclusion

Understanding, diagnosing, and using genetic testing for familial amyloid polyneuropathy, Iowa type, is essential for providing the best possible care for patients with this rare and complex disease. Genetic testing can help to confirm the diagnosis, identify the specific subtype of FAP, and enable families to make informed decisions about reproductive options. As our knowledge of FAP continues to expand, we can hope for improved diagnostic methods, better treatments, and ultimately, a cure for this devastating condition.

About The Expert Reviewer

Dr. Brandon Colby MD is a US physician specializing in the personalized prevention of disease through the use of genomic technologies. He’s an expert in genetic testing, genetic analysis, and precision medicine. Dr. Colby is also the Founder of  and the author of ⁠⁠Outsmart Your Genes.

Dr. Colby holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University’s Graduate School of Business, and a degree in Genetics with Honors from the University of Michigan. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (⁠⁠ACMG), an Associate of the American College of Preventive Medicine (⁠⁠ACPM), and a member of the National Society of Genetic Counselors (⁠NSGC)