Nonsyndromic hereditary hearing impairment

A type of genetic hearing loss not associated with other symptoms

Nonsyndromic hereditary hearing impairment
Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Hearing loss
Complications	N/A
Onset	Varies
Duration	Lifelong
Types	N/A
Causes	Genetic mutations
Risks	Family history
Diagnosis	Audiometry, Genetic testing
Differential diagnosis	N/A
Prevention	N/A
Treatment	Hearing aids, cochlear implants
Medication	N/A
Prognosis	N/A
Frequency	Varies by population
Deaths	N/A

Nonsyndromic hereditary hearing impairment (NSHI) refers to a form of hearing loss that is inherited and not associated with other clinical abnormalities. This type of hearing impairment is distinct from syndromic hearing loss, where hearing loss occurs in conjunction with other symptoms as part of a syndrome.

Genetics

Nonsyndromic hereditary hearing impairment is primarily caused by genetic mutations. These mutations can be inherited in an autosomal dominant, autosomal recessive, or X-linked manner. The most common form of inheritance is autosomal recessive, accounting for approximately 80% of cases.

Common Genes Involved

Several genes have been identified in association with NSHI. The most frequently implicated gene is GJB2, which encodes the protein connexin 26. Mutations in this gene are a leading cause of autosomal recessive nonsyndromic hearing loss. Other genes involved include GJB6, MYO7A, and OTOF.

Diagnosis

Diagnosis of nonsyndromic hereditary hearing impairment typically involves a combination of audiometric testing and genetic testing. Audiometric testing assesses the degree and type of hearing loss, while genetic testing can identify specific mutations responsible for the condition.

Management

Management of NSHI focuses on improving communication abilities and quality of life. This may include the use of hearing aids or cochlear implants. Early intervention and rehabilitation are crucial for optimal outcomes, especially in children.

Epidemiology

The prevalence of nonsyndromic hereditary hearing impairment varies widely among different populations. It is estimated that about 1 in 500 to 1 in 1000 newborns are affected by some form of genetic hearing loss.

Research and Future Directions

Ongoing research aims to better understand the genetic basis of NSHI and to develop gene therapy approaches. Advances in genomics and CRISPR technology hold promise for future treatments.

Also see

• Syndromic hearing loss
• Cochlear implant
• Audiometry
• Genetic testing