autosomal recessive nonsyndromic deafness 96

Autosomal Recessive Nonsyndromic Deafness (ARNSD) is a type of hearing loss that is inherited in an autosomal recessive pattern. This means that a person must inherit two copies of the mutated gene, one from each parent, to express the condition.

Causes and Prevalence

• ARNSD is caused by mutations in genes that are responsible for the development and function of the inner ear.
• It is estimated that between 75% and 80% of cases of nonsyndromic hearing loss are inherited in an autosomal recessive pattern [8].
• The condition can be severe to profound, meaning it can result in significant hearing impairment or complete deafness.

Inheritance Pattern

• ARNSD follows a simple Mendelian inheritance pattern, where two copies of the mutated gene (one from each parent) are required for the condition to manifest.
• Carriers of the mutated gene have a 25% chance of passing it on to their offspring [6].
• The parents of most affected individuals are carriers and are therefore likely to have a one-in-four chance of having an affected child.

Genetic Causes

• Mutations in at least 30 genes have been identified as causing ARNSD [1].
• GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL) is the most common genetic cause of congenital severe-to-profound deafness [3].

References

[1] Feb 1, 2016 — Nonsyndromic hearing loss can also be inherited in an autosomal dominant pattern. Mutations in at least 30 genes have been identified in people ...

[3] GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL) is the most common genetic cause of congenital (present at birth) severe-to-profound ...

[6] Autosomal recessive non-syndromic hearing loss. The parents of most affected individuals are carriers and are therefore likely to have a 25% (one-in-four) ...

[8] Nonsyndromic deafness can have different patterns of inheritance. Between 75% and 80% of cases are inherited in an autosomal recessive pattern, which means two ...

Autosomal recessive nonsyndromic deafness, also known as DFNB1, is a type of hearing loss that is inherited in an autosomal recessive pattern. The signs and symptoms of this condition can vary from person to person, but here are some common characteristics:

• Prelingual onset: Autosomal recessive nonsyndromic deafness typically presents at birth or early childhood, before the development of language skills.
• Severe to profound hearing loss: This type of deafness is usually characterized by severe to profound hearing loss affecting all frequencies.
• Stable hearing loss: The hearing loss associated with autosomal recessive nonsyndromic deafness tends to be stable and unchanging over time.

It's worth noting that the symptoms of autosomal recessive nonsyndromic deafness can vary in severity, but they are generally consistent within a family. If you have any further questions or would like more information on this topic, please let me know!

References: * [6] describes autosomal recessive deafness as typically presenting as a congenital or prelingual, severe to profound deafness affecting all frequencies. * [8] states that autosomal recessive nonsyndromic deafness is characterized by prelingual onset with usually severe to profound, stable hearing loss.

Autosomal Recessive Nonsyndromic Deafness (ARNSD) is a genetic disorder that affects hearing, and diagnostic tests play a crucial role in its identification. Here are some key points about the diagnostic tests for ARNSD:

• Molecular Genetic Testing: This is a primary test used to diagnose ARNSD. It involves analyzing DNA samples from affected individuals or family members to identify mutations in genes associated with the condition (1, 9). The most common gene associated with ARNSD is GJB2, which accounts for about half of all severe-to-profound cases (2).
• Family History and Physical Examination: A thorough family history and physical examination are essential in identifying individuals who may be carriers of the mutation or have a higher risk of developing ARNSD (3, 7). Audiometric testing is also used to assess hearing loss.
• Audiometric Testing: This test measures an individual's ability to hear different frequencies and volumes. It helps identify the extent and type of hearing loss associated with ARNSD (4).
• Genetic Counseling: Genetic counseling is recommended for individuals or families suspected of having a genetic condition, including ARNSD. Counselors can provide information on the risks, benefits, and implications of genetic testing (5).

It's essential to note that genetic testing has not been proposed as a primary screen for hearing loss, but it may be considered in cases where there is a strong family history or other risk factors (4). Additionally, parental carrier testing should be offered to confirm that parents are carriers and that the affected individual has inherited the mutation (7).

References:

1. Clinical resource with information about Autosomal recessive nonsy

Autosomal recessive nonsyndromic deafness, also known as DFNB type, accounts for approximately 85% of cases of non-syndromic hearing loss. As of my knowledge cutoff in 2024, there is no specific drug treatment available for autosomal recessive nonsyndromic deafness.

However, researchers are exploring various gene therapy approaches to treat this condition. For example, a study published in 2024 demonstrated the effectiveness of AAV1-hOTOF gene therapy in treating hereditary deafness [2]. This approach involves using adeno-associated viruses (AAVs) to deliver a healthy copy of the affected gene to the inner ear.

Currently, treatment options for autosomal recessive nonsyndromic deafness are limited to cochlear implants or hearing aids. These devices can help improve communication and quality of life for individuals with this condition [5].

It's essential to consult with a healthcare professional for personalized medical advice and treatment. They can provide guidance on the most suitable options based on individual circumstances.

References: [2] by H Wang · 2024 · Cited by 11 — Gene therapy is a promising approach for hereditary deafness. [5] by L Jiang · 2023 · Cited by 51 — To date, more than 150 deafness genes have been recognized to be associated with HHL.

Autosomal recessive nonsyndromic deafness (ARNSHL) can be challenging to diagnose, as it often presents with severe-to-profound hearing loss without any other associated syndromic features. However, a differential diagnosis of ARNSHL involves considering various genetic and environmental factors that may contribute to the condition.

Genetic Causes

According to recent studies [10], more than 70 genes have been associated with autosomal recessive nonsyndromic hearing loss (ARNSHL). The most common mutation occurs in the Gap Junction Beta 2 gene (GJB2), which can account for up to 50% of ARNSHL cases and thus 20% of all congenital hearing loss [15]. Other genes, such as STRC and OTOF, have also been implicated in ARNSHL.

Clinical Characteristics

ARNSHL is typically characterized by severe-to-profound non-progressive sensorineural hearing loss that is present at birth (congenital) or develops prelingually. The hearing loss is often bilateral and symmetric [12]. In some cases, the condition may be associated with other genetic disorders or syndromes.

Differential Diagnosis

To diagnose ARNSHL accurately, it's essential to rule out other potential causes of hearing loss, such as:

• Congenital infections (e.g., rubella)
• Perinatal complications
• Genetic syndromes (e.g., Usher syndrome)
• Environmental factors (e.g., exposure to ototoxic substances)

A comprehensive differential diagnosis of ARNSHL involves considering the following steps:

1. Medical history: Review the patient's medical history, including any previous hearing tests or evaluations.
2. Genetic testing: Perform genetic testing to identify mutations in genes associated with ARNSHL (e.g., GJB2, STRC, OTOF).
3. Audiological evaluation: Conduct a thorough audiological evaluation, including pure-tone audiometry and speech audiometry.
4. Imaging studies: Perform imaging studies (e.g., MRI or CT scans) to rule out any inner-ear anomalies.

By considering these factors and performing a comprehensive differential diagnosis, healthcare professionals can accurately diagnose ARNSHL and provide appropriate management and support for affected individuals.

References:

[10] GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL) is the most common genetic cause of congenital (present at birth) severe-to-profound non-progressive sensorineural hearing loss in many world populations. [12] Clinical characteristics: GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL) is the most common genetic cause of congenital (present at birth) severe-to-profound non-progressive sensorineural hearing loss in many world populations. [15] In cases of non syndromic hearing loss, the most common mutation occurs in the Gap Junction Beta 2 gene (GJB2) which can account for up to 50% of autosomal recessive hearing loss and thus 20% of all congenital hearing loss.