The onset of FAC caused by aggregation of the V122I mutation and wild-type TTR, and senile systemic amyloidosis caused by the exclusive aggregation of wild-type TTR, typically occur after age 60. Greater than 40% of these patients present with carpal tunnel syndrome before developing ATTR-CM. Cardiac involvement is often identified with the presence of conduction system disease (sinus node or atrioventricular node dysfunction) and/or congestive heart failure, including shortness of breath, peripheral edema, syncope, exertional dyspnea, generalized fatigue, or heart block. Unfortunately, echocardiographic findings are indistinguishable from those seen in AL amyloidosis, and include thickened ventricular walls (concentric hypertrophy, both right and left) with a normal-to-small left ventricular cavity, increased myocardial echogenicity, normal or mildly reduced ejection fraction (often with evidence of diastolic dysfunction and severe impairment of contraction along the longitudinal axis), and bi-atrial dilation with impaired atrial contraction. Unlike the situation in AL amyloidosis, the ECG voltage is often normal, although low voltage may be seen (despite increased wall thickness on echocardiography). Marked axis deviation, bundle branch block, and AV block are common, as is atrial fibrillation.

Wild-type transthyretin amyloid accumulates mainly in the heart, where it causes stiffness and often thickening of its walls, leading consequently to shortness of breath and intolerance to exercise, called diastolic dysfunction. Excessively slow heart rate can also occur, such as in sick sinus syndrome, with ensuing fatigue and dizziness. Wild-type transthyretin deposition is also a common cause of carpal tunnel syndrome in elderly men, which may cause pain, tingling and loss of sensation in the hands. Some patients may develop carpal tunnel syndrome as an initial symptom of wild-type transthyretin amyloid.

There appears to be an increase in the risk for developing hematuria or blood in the urine due to urological lesions.

A triad of hypokalemic periodic paralysis, potentially fatal cardiac ventricular ectopy and characteristic physical features is known as Anderson-Tawil Syndrome. It affects the heart, symptoms are a disruption in the rhythm of the heart's lower chambers (ventricular arrhythmia) in addition to the symptoms of long QT syndrome. There are also physical abnormalities associated with Andersen–Tawil syndrome, these typically affect the head, face, and limbs. These features often include an unusually small lower jaw (micrognathia), low-set ears, and an abnormal curvature of the fingers called clinodactyly. Furthermore it causes symptoms which are similar to Long QT syndrome, which Andersen's is also known as. Long QT syndrome, a hereditary disorder that usually affects children or young adults, slows the signal that causes the ventricles to contract. Another electrical signal problem, atrial flutter, happens when a single electrical wave circulates rapidly in the atrium, causing a very fast but steady heartbeat. Heart block involves weak or improperly conducted electrical signals from the upper chambers that can't make it to the lower chambers, causing the heart to beat too slowly. These conditions can put you at risk for cardiac arrest. Treatment might involve medication, ablation, or an implanted device to correct the misfiring, such as a pacemaker or defibrillator. Here are some common physical abnormalities, but keep in mind these do vary (in severity) between each patient:

Some more severe issues can be caused via the potassium channelopathy. These include paralysis (mostly temporary and can last from several seconds to several minutes), inability to perform long distance/interval exercises and sudden exhaustion- although this can be a sign of cardiac arrhythmia- which should be immeditaley checked out by a GP, whether you have been diagnosed with ATS or not.

Familial Amyloid Cardiomyopathy (FAC), or Transthyretin Amyloid Cardiomyopathy (ATTR-CM) results from the aggregation and deposition of mutant and wild-type transthyretin (TTR) protein in the heart. TTR amyloid fibrils infiltrate the myocardium, leading to diastolic dysfunction from restrictive cardiomyopathy, and eventual heart failure. Both mutant and wild-type transthyretin comprise the aggregates because the TTR blood protein is a tetramer composed of mutant and wild-type TTR subunits in heterozygotes. Several mutations in TTR are associated with FAC, including V122I, V20I, P24S, A45T, Gly47Val, Glu51Gly, I68L, Gln92Lys, and L111M. One common mutation (V122I), which is a substitution of isoleucine for valine at position 122, occurs with high frequency in African-Americans, with a prevalence of approximately 3.5%. FAC is clinically similar to senile systemic amyloidosis, in which cardiomyopathy results from the aggregation of wild-type transthyretin exclusively.

Wild-type transthyretin amyloid (WTTA), also known as senile systemic amyloidosis (SSA) and abbreviated as ATTR, is a disease that typically affects the heart and tendons of elderly people. It is caused by accumulation of a wild-type (that is to say a normal) protein called transthyretin. This is in contrast to a related condition called transthyretin-related hereditary amyloidosis where a genetically mutated transthyretin protein tends to deposit at a much earlier age than in WTTA, due to abnormal conformation and bioprocessing.

It belongs to a group of diseases called amyloidosis, chronic progressive conditions linked to abnormal deposition of normal or abnormal proteins, because these proteins are misshapen and cannot be properly degraded and eliminated by the cell metabolism.

Up to 80% of individuals with ARVD present have symptoms like syncope and dyspnea.The remainder frequently present with palpitations or other symptoms due to right ventricular outflow tract (RVOT) tachycardia (a type of monomorphic ventricular tachycardia).

Symptoms are usually exercise-related. In populations where hypertrophic cardiomyopathy is screened out prior to involvement in competitive athletics, it is a common cause of sudden cardiac death.

The first clinical signs of ARVD are usually during adolescence. However, signs of ARVD have been demonstrated in infants.

These most often occur years after the development of ptosis and ophthalmoplegia. Atrioventricular(abbreviated "AV") block is the most common cardiac conduction deficit. This often progresses to a Third-degree atrioventricular block, which is a complete blockage of the electrical conduction from the atrium to the ventricle. Symptoms of heart block include syncope, exercise intolerance, and bradycardia

Usually manifesting itself between 20 and 40 years of age, it is characterized by pain, paresthesia, muscular weakness and autonomic dysfunction. In its terminal state, the kidneys and the heart are affected. FAP is characterized by the systemic deposition of amyloidogenic variants of the transthyretin protein, especially in the peripheral nervous system, causing a progressive sensory and motor polyneuropathy.

Arrhythmogenic right ventricular dysplasia (ARVD) is an inherited heart disease.

ARVD is caused by genetic defects of the parts of heart muscle (also called "myocardium" or "cardiac muscle") known as desmosomes, areas on the surface of heart muscle cells which link the cells together. The desmosomes are composed of several proteins, and many of those proteins can have harmful mutations.

The disease is a type of nonischemic cardiomyopathy that involves primarily the right ventricle. It is characterized by hypokinetic areas involving the free wall of the right ventricle, with fibrofatty replacement of the right ventricular myocardium, with associated arrhythmias originating in the right ventricle.

ARVD can be found in association with diffuse palmoplantar keratoderma, and woolly hair, in an autosomal recessive condition called Naxos disease, because this genetic abnormality can also affect the integrity of the superficial layers of the skin most exposed to pressure stress.

ARVC/D is an important cause of ventricular arrhythmias in children and young adults. It is seen predominantly in males, and 30–50% of cases have a familial distribution.

An alternative name of the condition, LEOPARD syndrome, is a mnemonic, originally coined in 1969, as the condition is characterized by some of the following seven conditions, the first letters of which spell LEOPARD, along with the characteristic "freckling" of the skin, caused by the lentigines that is reminiscent of the large cat.

- Lentigines — Reddish-brown to dark brown macules (surface skin lesion) generally occurring in a high number (10,000+) over a large portion of the skin, at times higher than 80% coverage. These can even appear inside the mouth (buccal), or on the surface of the eye (scleral). These have irregular borders and range in size from 1 mm in diameter to café-au-lait spots, several centimeters in diameter. Also, some areas of vitiligo-like hypopigmentation may be observed.

- Electrocardiographic conduction abnormalities: Generally observed on an electrocardiograph as a bundle branch block.

- Ocular hypertelorism: Wideset eyes, which lead to a similar facial resemblance between patients. Facial abnormalities are the second highest occurring symptom after the lentigines. Abnormalities also include: broad nasal root, prognathism (protruding lower jaw), or low-set, possibly rotated, ears.

- Pulmonary stenosis: Narrowing of the pulmonary artery as it exits the heart. Other cardiac abnormalities may be present, including aortic stenosis, or mitral valve prolapse.

- Abnormal genitalia: usually cryptorchidism (retention of testicles in body) or monorchism (single testicle). In female patients, this presents as missing or single ovaries, much harder by nature to detect. Ultrasound imaging is performed at regular intervals, from the age of 1 year, to determine if ovaries are present.

- Retarded growth: Slow, or stunted growth. Most newborns with this syndrome are of normal birth weight and length, but will often slow within the first year.

- Deafness: Sensorineural (nerve deafness).

The presence of all of these hallmarks is not needed for a diagnosis. A clinical diagnosis is considered made when, with lentigines present there are 2 other symptoms observed, such as ECG abnormalities and ocular hypertelorism, or without lentigines, 3 of the above conditions are present, with a first-degree relative (i.e. parent, child, sibling) with a clinical diagnosis.

- Additional dermatologic abnormalities (axillary freckling, localized hypopigmentation, interdigital webbing, hyperelastic skin)

- Mild mental retardation is observed in about 30% of those affected with the syndrome

- Nystagmus (involuntary eye movements), seizures, or hyposmia (reduced ability to smell) has been documented in a few patients

- In 2004, a patient was reported with recurrent upper extremity aneurysms that required surgical repairs.

- In 2006, a NSML patient was reported with acute myelogenous leukemia.

Due to the rarity of the syndrome itself, it is hard to determine whether certain additional diseases are actually part of the syndrome. With a base population of possibly less than one thousand individuals, one or two outlying cases can skew the statistical population very quickly.

Individuals with KSS present initially in a similar way to those with typical CPEO. Onset is in the first and second decades of life.

The first symptom of this disease is a unilateral ptosis, or difficulty opening the eyelids, that gradually progresses to a bilateral ptosis. As the ptosis worsens, the individual commonly extends their neck, elevating their chin in an attempt to prevent the eyelids from occluding the visual axis. Along with the insidious development of ptosis, eye movements eventually become limited causing a person to rely more on turning the head side to side or up and down to view objects in the peripheral visual field.

Familial amyloid polyneuropathy (FAP), also called transthyretin-related hereditary amyloidosis, transthyretin amyloidosis abbreviated also as ATTR (hereditary form), or Corino de Andrade's disease, is an autosomal dominant neurodegenerative disease. It is a form of amyloidosis, and was first identified and described by Portuguese neurologist Mário Corino da Costa Andrade, in 1952. FAP is distinct from senile systemic amyloidosis (SSA), which is not inherited, and which was determined to be the primary cause of death for 70% of supercentenarians who have been autopsied.

FAP can be ameliorated by liver transplantation.

Symptoms may occur at any time, but most often they accompany a change of body position. Pedunculated myxomas can have a "wrecking ball effect", as they lead to stasis and may eventually embolize themselves. Symptoms may include:

- Shortness of breath with activity

- Platypnea – Difficulty breathing in the upright position with relief in the supine position

- Paroxysmal nocturnal dyspnea – Breathing difficulty when asleep

- Dizziness

- Fainting

- Palpitations – Sensation of feeling your heart beat

- Chest pain or tightness

- Sudden Death (In which case the disease is an autopsy finding)

The symptoms and signs of left atrial myxomas often mimic mitral stenosis.

General symptoms may also be present, such as:

- Cough

- Pulmonary edema, as blood backs up into the pulmonary artery, after increased pressures in the left atrium and atrial dilation

- Hemoptysis

- Fever

- Cachexia – Involuntary weight loss

- General discomfort (malaise)

- Joint pain

- Blue discoloration of the skin, especially the fingers (Raynaud's phenomenon)

- Fingers that change color upon pressure or with cold or stress

- Clubbing – Curvature of nails accompanied with soft tissue enlargement of the fingers

- Swelling – any part of the body

- Presystolic heart murmur

These general symptoms may also mimic those of infective endocarditis.

There is considerable variability in the phenotype of Loeys–Dietz syndrome, from mild features to severe systemic abnormalities. The primary manifestations of Loeys–Dietz syndrome are arterial tortuosity (winding course of blood vessels), widely spaced eyes (hypertelorism), wide or split uvula, and aneurysms at the aortic root. Other features may include cleft palate and a blue/gray appearance of the white of the eyes. Cardiac defects and club foot may be noted at birth.

There is overlap in the manifestations of Loeys–Dietz and Marfan syndromes, including increased risk of ascending aortic aneurysm and aortic dissection, abnormally long limbs and fingers, and dural ectasia (a gradual stretching and weakening of the dura mater that can cause abdominal and leg pain). Findings of hypertelorism (widely spaced eyes), bifrid or split uvula, and skin findings such as easy bruising or abnormal scars may distinguish Loys-Dietz from Marfan syndrome.

Findings of Loys-Dietz syndrome may include:

- Skeletal/spinal malformations: craniosynositosis, Scoliosis, spinal instability and spondylolisthesis, Kyphosis

- Sternal abnormalities: pectus excavatum, pectus carinatum

- Contractures of fingers and toes (camptodactyly)

- Long fingers and lax joints

- Weakened or missing eye muscles (strabismus)

- Club foot

- Premature fusion of the skull bones (craniosynostosis)

- Joint hypermobility

- Congenital heart problems including patent ductus arteriosus (connection between the aorta and the lung circulation) and atrial septal defect (connection between heart chambers)

- Translucency of the skin with velvety texture

- Abnormal junction of the brain and medulla (Arnold-Chiari malformation)

- Bicuspid aortic valves

- Criss-crossed pulmonary arteries

Andersen–Tawil syndrome, also called Andersen syndrome and Long QT syndrome 7, is a form of long QT syndrome. It is a rare genetic disorder, and is inherited in an autosomal dominant pattern and predisposes patients to cardiac arrhythmias. Jervell and Lange-Nielsen Syndrome is a similar disorder which is also associated with sensorineural hearing loss. It was first described by Ellen Damgaard Andersen.

Stokes-Adams attacks may be diagnosed from the history, with paleness prior to the attack and flushing after it particularly characteristic. The ECG will show asystole, an AV block, or ventricular fibrillation during the attacks.

Brugada syndrome (BrS) is a genetic condition that results in abnormal electrical activity within the heart, increasing the risk of sudden cardiac death. Those affected may have episodes of passing out. Typically this occurs when a person is at rest.

It is often inherited from a person's parent with about a quarter of people having a family history. Some cases may be due to a new mutation or certain medications. The abnormal heart rhythms can be triggered by a fever or increased vagal tone. Diagnosis is typically by electrocardiogram (ECG), however, the abnormalities may not be consistently present.

Treatment may be with an implantable cardioverter defibrillator (ICD). Isoproterenol may be used in those who are acutely unstable. In those without symptoms the risk of death is much lower, and how to treat this group is unclear. Testing people's family members may be recommended.

Between 1 and 30 per 10,000 people are affected. Onset of symptoms is usually in adulthood. It is more common in people of Asian descent. Males are more commonly affected than females. It is named after the Spanish cardiologists Pedro and Josep Brugada who described the condition in 1992. Their brother Ramon Brugada described the underlying genetics in 1998.

Typically an attack occurs without warning leading to sudden loss of consciousness. Prior to an attack, a patient may be pale with hypoperfusion. Normal periods of unconsciousness last approximately thirty seconds; if abnormal movements are present, they will consist of twitching after 15–20 seconds (The movements, which are not seizures occur because of brainstem hypoxia and not due to cortical discharge as evident by EEG findings which show no epileptiform activities). Breathing continues normally throughout the attack, and upon recovery the patient becomes flushed as the heart rapidly pumps the oxygenated blood from the pulmonary beds into a systemic circulation, which has become dilated due to hypoxia.

As with any syncopal episode that results from a cardiac dysrhythmia, the faints do not depend on the patient's position. If they occur during sleep, the presenting symptom may simply be feeling hot and flushed on waking.

Noonan syndrome with multiple lentigines (NSML) which is part of a group called Ras/MAPK pathway syndromes, is a rare autosomal dominant, multisystem disease caused by a mutation in the protein tyrosine phosphatase, non-receptor type 11 gene ("PTPN11"). The disease is a complex of features, mostly involving the skin, skeletal and cardiovascular systems, which may or may not be present in all patients. The nature of how the mutation causes each of the condition's symptoms is not well known; however, research is ongoing. It is a RASopathy.

Noonan syndrome with multiple lentigines is caused by a different missense mutation of the same gene. Noonan syndrome is fairly common (1:1,000 to 1:2,500 live births), and neurofibromatosis 1 (which was once thought to be related to NSML) is also common (1:3500); however, no epidemiological data exists for NSML.

Familial partial lipodystrophy (FPL), also known as Köbberling–Dunnigan syndrome, is a rare genetic metabolic condition characterized by the loss of subcutaneous fat.

FPL also refers to a rare metabolic condition in which there is a loss of subcutaneous fat in the arms, legs and lower torso. The upper section of the body, face, neck, shoulders, back and trunk carry an excess amount of fat.

As the body is unable to store fat correctly this leads to fat around all the vital organs and in the blood (triglycerides). This results in heart problems, cirrhosis of the liver, lipoatrophic diabetes, and pancreatitis, along with various other complications.

FHM signs overlap significantly with those of migraine with aura. In short, FHM is typified by migraine with aura associated with hemiparesis and, in FHM1, cerebellar degeneration. This cerebellar degeneration can result in episodic or progressive ataxia. FHM can also present with the same signs as benign familial infantile convulsions (BFIC) and alternating hemiplegia of childhood. Other symptoms are altered consciousness (in fact, some cases seem related to head trauma), gaze-evoked nystagmus and coma. Aura symptoms, such as numbness and blurring of vision, typically persist for 30–60 minutes, but can last for weeks and months. An attack resembles a stroke, but unlike a stroke, it resolves in time. These signs typically first manifest themselves in the first or second decade of life.

Familial atrial fibrillation is an autosomal dominant heart condition that causes disruptions in the heart's normal rhythm. This condition is characterized by uncoordinated electrical activity in the heart's upper chambers (the atria), which causes the heartbeat to become fast and irregular.

Type 1 usually begins somewhere in the first three to 18 months of age and in considered the most severe of the three types. Symptoms include:

- Coarse facial features

- Enlarged liver, spleen, and/or heart

- Intellectual disability

- Seizures

- Abnormal bone formation of many bones

- Progressive deterioration of brain and spinal cord

- Increased or decreased perspiration

Patients have no vascular lesions, but have rapid psychomotor regression, severe and rapidly progressing neurologic signs, elevated sodium and chloride excretion in the sweat, and fatal outcome before the sixth year.

Trifascicular block is a problem with the electrical conduction of the heart. It is diagnosed on an electrocardiogram (ECG/EKG) and has three features:

- prolongation of the (first degree AV block)

- right bundle branch block

- either left anterior fascicular block or left posterior fascicular block.

The most distinctive clinical feature is the absence of overflow tears with emotional crying after age 7 months. This symptom can manifest less dramatically as persistent bilateral eye irritation. There is also a high prevalence of breech presentation. Other symptoms include weak or absent suck and poor tone, poor suck and misdirected swallowing, and red blotching of skin.

Symptoms in an older child with familial dysautonomia might include:

1. Delayed speech and walking

2. Unsteady gait

3. Spinal curvature

4. Corneal abrasion

5. Less perception in pain or temperature with nervous system.

6. Poor growth

7. Erratic or unstable blood pressure.

8. Red puffy hands

9. Dysautonomia crisis: a constellation of symptoms in response to physical and emotional stress; usually accompanied by vomiting, increased heart rate, increase in blood pressure, sweating, drooling, blotching of the skin and a negative change in personality.