Nerve damage, also known as neuropathy, can have many causes. In some cases, neuropathy is an inherited condition. Hereditary neuropathies include a group of inherited conditions that affect the peripheral nervous system.

Neuropathy involves damage to the nerves that can interfere with their function. It can occur due to an inherited condition, where a biological parent passes on a gene that can lead to neuropathy in their offspring. It can also be an “acquired” condition. Acquired neuropathy develops due to various conditions, injuries, and as a medication side effect.

Usually, inherited neuropathy involves the peripheral nerves, which send signals from the spinal cord and brain to the other parts of the body. When nerve damage occurs, it can lead to various symptoms, such as pain, numbness, and muscle weakness.

This article will cover the different types of inherited neuropathies, testing methods, and risk factors.

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Genetics can play a role in the development of neuropathy. Hereditary neuropathy refers to a group of inherited conditions affecting the peripheral nervous system. Research suggests the prevalence of these conditions is approximately 1 in 2,500 people.

A 2018 review identified variations in more than 100 genes that may cause hereditary neuropathy. Different genes may lead to the development of varied forms of inherited neuropathy. Additionally, alterations in the same gene may lead to clinically distinct forms of neuropathy.

Symptoms may also vary depending on the type of inherited neuropathy. Motor or sensory symptoms can occur. In some instances, the condition also affects the autonomic nerves, causing impaired sweating, low blood pressure, and insensitivity to pain.

Various types of hereditary neuropathies exist, including the following:

Hereditary motor and sensory neuropathy

This progressive nerve condition is also known as Charcot-Marie-Tooth (CMT) disease. It affects both the motor and sensory nerves and can lead to numbness and weakness, with symptoms affecting the legs more than the arms.

CMT disease is the most common type of inherited neuropathy. Symptoms may vary but can include:

Hereditary sensory neuropathy

Hereditary sensory neuropathy affects the sensory nerves, especially those controlling the feet and hands. The sensory nerves control the response to temperature, pain, and touch. People with hereditary sensory neuropathy often lose feeling in their hands and feet.

There are also varied subtypes of hereditary sensory neuropathies, each associated with a different gene. Researchers designate each subtype of sensory neuropathy with a letter A through F.

Symptoms may vary widely but can include:

  • loss of feeling in the lower portions of the arms and legs
  • an inability to feel touch
  • an inability to distinguish hot from cold

Hereditary motor neuropathy

Hereditary motor neuropathy causes motor symptoms without causing sensory or autonomic symptoms. Various gene variations can lead to hereditary motor neuropathy. Possible symptoms include:

  • progressive weakness of certain muscles
  • joint deformities in the feet
  • decreased reflexes

Hereditary sensory and autonomic neuropathy

Hereditary sensory and autonomic neuropathy involves both the sensory and autonomic nerves in the body. It is a rare, progressive form of neuropathy.

The condition is associated with variations in several genes and has subtypes A through D. Each subtype is associated with a different gene.

Symptoms are highly variable. For instance, hereditary sensory and autonomic neuropathy may affect one nerve or several nerves at the same time. Symptoms can include:

The most significant risk factor for developing inherited neuropathy includes having a parent with the condition or carrying specific gene alterations.

For example, if one parent has CMT disease, there is a 50% chance they will pass the condition on to their children. However, it is also possible for a person to develop CMT randomly.

In addition to the identified gene variations associated with the condition, researchers theorize unidentified genes may contribute to inherited neuropathies.

Some studies suggest certain risk factors may make symptoms more severe in people with inherited neuropathy. A 2017 study suggests that risk factors for worsening symptoms include:

A person may experience symptoms of hereditary neuropathy at birth. However, in other cases, symptoms may appear in middle or late life.

To diagnose these conditions, a doctor can use:

  • nerve conduction studies
  • nerve biopsies
  • blood tests for genetic testing

A thorough diagnostic evaluation can also help rule out other potential neuropathy causes, such as other health conditions, nutritional deficiencies, or infections.

Learning the genetic cause of neuropathy may help people decide between treatment options and inform other family members about their chances of developing it.

An individual with a genetic predisposition for neuropathy may take steps to avoid risk factors that may worsen symptoms, such as obesity.

Inherited neuropathies involve a group of conditions that interfere with nerve function. Inherited neuropathies occur due to a gene passed on from a biological parent to a child. Researchers have identified many different genes that appear to play a role in inherited neuropathies.

Different forms of inherited neuropathy can occur that affect the body’s motor, sensory, and autonomic nerves. Symptoms often include pain, numbness, and muscle weakness. Genetic testing can help determine if a person has an inherited gene that causes a form of neuropathy.