MedGen

Peripheral neuropathy affecting the sensory nerves. [from HPO]

A decreased magnitude of the sensory perception of sound. [from HPO]

An inherited or acquired peripheral neuropathy affecting the autonomic nervous system. It results in disruption of the involuntary body functions. Inherited causes include Fabry disease and porphyrias. Acquired causes include diabetes, uremia, hepatic disorders, vitamin deficiencies, toxins, and drug toxicities. [from NCI]

Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course. [from HPO]

An instance of sensory peripheral neuropathy that is caused by an inherited modification of the individual's genome. [from MONDO]

Classic ataxia-telangiectasia (A-T) is characterized by progressive cerebellar ataxia beginning between ages one and four years, oculomotor apraxia, choreoathetosis, telangiectasias of the conjunctivae, immunodeficiency, frequent infections, and an increased risk for malignancy, particularly leukemia and lymphoma. Individuals with A-T are unusually sensitive to ionizing radiation. Non-classic forms of A-T have included adult-onset A-T and A-T with early-onset dystonia. [from GeneReviews]

An abnormality of the nervous system. [from HPO]

Inflammation or degeneration of the peripheral motor nerves. [from MONDO]

A disorder characterized by the partial or complete loss of the ability to detect sounds due to damage to the ear structures or inability of the brain to properly interpret or process the auditory signals it receives from the anatomic structures of the ear. [from NCI]

A non-neoplastic or neoplastic disorder that affects the ear. Representative examples include infections, hearing disorders, benign neoplasms, and carcinomas. [from NCI]

Hereditary sensory and autonomic neuropathy type II (HSAN2) is characterized by progressively reduced sensation to pain, temperature, and touch. Onset can be at birth and is often before puberty. The sensory deficit is predominantly distal with the lower limbs more severely affected than the upper limbs. Over time sensory function becomes severely reduced. Unnoticed injuries and neuropathic skin promote ulcerations and infections that result in spontaneous amputation of digits or the need for surgical amputation. Osteomyelitis is common. Painless fractures can complicate the disease. Autonomic disturbances are variable and can include hyperhidrosis, tonic pupils, and urinary incontinence in those with more advanced disease. [from GeneReviews]

NTRK1 congenital insensitivity to pain with anhidrosis (NTRK1-CIPA) is characterized by insensitivity to pain, anhidrosis (the inability to sweat), and intellectual disability. The ability to sense all pain (including visceral pain) is absent, resulting in repeated injuries including: oral self-mutilation (biting of tongue, lips, and buccal mucosa); biting of fingertips; bruising, scarring, and infection of the skin; multiple bone fractures (many of which fail to heal properly); and recurrent joint dislocations resulting in joint deformity. Sense of touch, vibration, and position are normal. Anhidrosis predisposes to recurrent febrile episodes that are often the initial manifestation of NTRK1-CIPA. Hypothermia in cold environments also occurs. Intellectual disability of varying degree is observed in most affected individuals; hyperactivity and emotional lability are common. [from GeneReviews]

SPTLC1-related hereditary sensory neuropathy (HSN) is an axonal form of hereditary motor and sensory neuropathy distinguished by prominent early sensory loss and later positive sensory phenomena including dysesthesia and characteristic "lightning" or "shooting" pains. Loss of sensation can lead to painless injuries, which, if unrecognized, result in slow wound healing and subsequent osteomyelitis requiring distal amputations. Motor involvement is present in all advanced cases and can be severe. After age 20 years, the distal wasting and weakness may involve proximal muscles, possibly leading to wheelchair dependency by the seventh or eighth decade. Sensorineural hearing loss is variable. [from GeneReviews]

Syndrome with the association of sensorineural hearing impairment and peripheral neuropathy. It has been described in members from four generations of a Spanish family. The hearing impairment was mild and often asymmetrical. The neuropathy was demyelinating with predominantly sensory involvement but severity was variable ranging from asymptomatic individuals to patients with skin ulcers and osteomyelitis requiring amputation. Caused by mutations in the GJB3 gene (1p34). The syndrome is transmitted in an autosomal dominant manner. [from SNOMEDCT_US]

Nonsyndromic hearing loss is a partial or total loss of hearing that is not associated with other signs and symptoms. In contrast, syndromic hearing loss occurs with signs and symptoms affecting other parts of the body.

Nonsyndromic hearing loss can be classified in several different ways. One common way is by the condition's pattern of inheritance: autosomal dominant (DFNA), autosomal recessive (DFNB), X-linked (DFNX), or mitochondrial (which does not have a special designation). Each of these types of hearing loss includes multiple subtypes. DFNA, DFNB, and DFNX subtypes are numbered in the order in which they were first described. For example, DFNA1 was the first type of autosomal dominant nonsyndromic hearing loss to be identified.

The characteristics of nonsyndromic hearing loss vary among the different types. Hearing loss can affect one ear (unilateral) or both ears (bilateral). Degrees of hearing loss range from mild (difficulty understanding soft speech) to profound (inability to hear even very loud noises). The term "deafness" is often used to describe severe-to-profound hearing loss. Hearing loss can be stable, or it may be progressive, becoming more severe as a person gets older. Particular types of nonsyndromic hearing loss show distinctive patterns of hearing loss. For example, the loss may be more pronounced at high, middle, or low tones.

Most forms of nonsyndromic hearing loss are described as sensorineural, which means they are associated with a permanent loss of hearing caused by damage to structures in the inner ear. The inner ear processes sound and sends the information to the brain in the form of electrical nerve impulses. Less commonly, nonsyndromic hearing loss is described as conductive, meaning it results from changes in the middle ear. The middle ear contains three tiny bones that help transfer sound from the eardrum to the inner ear. Some forms of nonsyndromic hearing loss, particularly a type called DFNX2, involve changes in both the inner ear and the middle ear. This combination is called mixed hearing loss.

Depending on the type, nonsyndromic hearing loss can become apparent at any time from infancy to old age. Hearing loss that is present before a child learns to speak is classified as prelingual or congenital. Hearing loss that occurs after the development of speech is classified as postlingual. [from MedlinePlus Genetics]

Hereditary sensory and autonomic neuropathy type V (HSAN5) is a condition that primarily affects the sensory nerve cells (sensory neurons), which transmit information about sensations such as pain, temperature, and touch. These sensations are impaired in people with HSAN5.

The signs and symptoms of HSAN5 appear early, usually at birth or during infancy. People with HSAN5 lose the ability to feel pain, heat, and cold. Deep pain perception, the feeling of pain from injuries to bones, ligaments, or muscles, is especially affected in people with HSAN5. Because of the inability to feel deep pain, affected individuals suffer repeated severe injuries such as bone fractures and joint injuries that go unnoticed. Repeated trauma can lead to a condition called Charcot joints, in which the bones and tissue surrounding joints are destroyed. [from MedlinePlus Genetics]