From OMIM
Hereditary amyloidoses are a clinically and genetically heterogeneous group of autosomal dominantly inherited diseases characterized by the deposit of unsoluble protein fibrils in the extracellular matrix (summary by Hund et al., 2001). Patients with transthyretin amyloidosis typically present with polyneuropathy, carpal tunnel syndrome, autonomic insufficiency, cardiomyopathy, and gastrointestinal features, occasionally accompanied by vitreous opacities and renal insufficiency. In later stages of the disease severe diarrhea with malabsorption, cachexia, incapacitating neuropathy, severe cardiac disturbances, and marked orthostatic hypotension dominate the clinical picture. Death usually occurs 5 to 15 years after onset of symptoms. Before the emergence of molecular genetics, hereditary amyloidoses were classified into 4 subtypes according to symptom constellation and ethnic origin (summary by Hund et al., 2001). The course of disease beginning with sensorimotor polyneuropathy that starts in early adulthood symmetrically at the legs and progresses rather rapidly to incapacitate the patient within a few years has been labeled familial amyloid polyneuropathy type I (FAP I), also known as Portuguese, Portuguese-Swedish-Japanese, or Andrade type. FAP I can be considered the prototype of the manifestation of hereditary TTR amyloidosis. The overwhelming majority of cases of FAP I result from a val30-to-met (V30M; 176300.0001) substitution. A course of disease with neuropathy beginning at the hands and frequent carpal tunnel operations has been designated FAP II, also known as the Indiana/Swiss (176300.0006) or Maryland/German (176300.0003) type. Vitreous opacities occur early in the disease course, whereas impotence and renal insufficiency are rare. Amyloidosis due to mutations in the APOA1 gene (107650) has been referred to as FAP III or Iowa type (see 105200 and 107680.0010). The Finnish type of amyloidosis (105120) has been referred to as FAP IV and is caused by mutations in gelsolin (137350). Systems based on clinical phenotypes have historically been used to classify the amyloidoses, but emphasis on the characterization of the amyloid fibril protein has proved more useful (Saraiva, 2002). In addition to hereditary amyloidosis, 2 other major forms of systemic amyloidosis exist. Immunoglobulin (AL) amyloidosis, formerly known as primary amyloidosis, is caused by the accumulation of monoclonal immunoglobulin (Ig) light chains as amyloid fibrils. Reactive (AA) amyloidosis, formerly known as secondary amyloidosis, is associated with chronic inflammatory diseases (e.g., rheumatoid arthritis, 180300; familial Mediterranean fever, 249100), and fibrils are derived from the circulating acute-phase reactant serum amyloid A protein (see 104750). Ando et al. (2005) provided a review of transthyretin-related familial amyloid polyneuropathy. The authors stated that the phenotypes can be classified into neuropathic, oculoleptomeningeal, and cardiac.  http://www.omim.org/entry/105210

From MedlinePlus Genetics
Transthyretin amyloidosis is a slowly progressive condition characterized by the buildup of abnormal deposits of a protein called amyloid (amyloidosis) in the body's organs and tissues. These protein deposits most frequently occur in the peripheral nervous system, which is made up of nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound. Protein deposits in these nerves result in a loss of sensation in the extremities (peripheral neuropathy). The autonomic nervous system, which controls involuntary body functions such as blood pressure, heart rate, and digestion, may also be affected by amyloidosis. In some cases, the brain and spinal cord (central nervous system) are affected. Other areas of amyloidosis include the heart, kidneys, eyes, and gastrointestinal tract. The age at which symptoms begin to develop varies widely among individuals with this condition, and is typically between ages 20 and 70.

There are three major forms of transthyretin amyloidosis, which are distinguished by their symptoms and the body systems they affect.

The neuropathic form of transthyretin amyloidosis primarily affects the peripheral and autonomic nervous systems, resulting in peripheral neuropathy and difficulty controlling bodily functions. Impairments in bodily functions can include sexual impotence, diarrhea, constipation, problems with urination, and a sharp drop in blood pressure upon standing (orthostatic hypotension). Some people experience heart and kidney problems as well. Various eye problems may occur, such as cloudiness of the clear gel that fills the eyeball (vitreous opacity), dry eyes, increased pressure in the eyes (glaucoma), or pupils with an irregular or "scalloped" appearance. Some people with this form of transthyretin amyloidosis develop carpal tunnel syndrome, which is characterized by numbness, tingling, and weakness in the hands and fingers.

The leptomeningeal form of transthyretin amyloidosis primarily affects the central nervous system. In people with this form, amyloidosis occurs in the leptomeninges, which are two thin layers of tissue that cover the brain and spinal cord. A buildup of protein in this tissue can cause stroke and bleeding in the brain, an accumulation of fluid in the brain (hydrocephalus), difficulty coordinating movements (ataxia), muscle stiffness and weakness (spastic paralysis), seizures, and loss of intellectual function (dementia). Eye problems similar to those in the neuropathic form may also occur. When people with leptomeningeal transthyretin amyloidosis have associated eye problems, they are said to have the oculoleptomeningeal form.

The cardiac form of transthyretin amyloidosis affects the heart. People with cardiac amyloidosis may have an abnormal heartbeat (arrhythmia), an enlarged heart (cardiomegaly), or orthostatic hypertension. These abnormalities can lead to progressive heart failure and death. Occasionally, people with the cardiac form of transthyretin amyloidosis have mild peripheral neuropathy.  https://medlineplus.gov/genetics/condition/transthyretin-amyloidosis