autosomal recessive nonsyndromic deafness 74

Autosomal recessive nonsyndromic deafness 74, also known as DFNB74, is a form of non-syndromic sensorineural deafness characterized by prelingual, bilateral, and profound hearing loss [1]. This condition results from a mutation in the MSRB3 gene located on chromosome 12q14.2-q15 [4].

The clinical features of autosomal recessive nonsyndromic deafness 74 include:

• Prelingual onset: Hearing loss occurs before language development, typically in infancy or early childhood
• Bilateral involvement: Both ears are affected, resulting in profound hearing loss
• Profound hearing loss: The degree of hearing loss is severe, with little to no residual hearing

It's essential to note that autosomal recessive nonsyndromic deafness 74 is a genetic condition, and its inheritance pattern follows an autosomal recessive trait [3]. This means that an individual must inherit two copies of the mutated gene (one from each parent) to express the condition.

References:

[1] Definition. Any autosomal recessive nonsyndromic deafness in which the cause of the disease is a mutation in the MSRB3 gene. [from MONDO]. Clinical features. [4] Deafness, autosomal recessive 74 is a form of non-syndromic sensorineural deafness characterized by prelingual, bilateral, profound hearing loss. It results ... [3] Autosomal dominant nonsyndromic deafness 74 is caused by a heterozygous mutation in the PDE1C gene located on chromosome 7p14.3. Categories. Global: Genetic ...

Autosomal recessive nonsyndromic deafness 74 (DFNB74) is a genetic disorder that affects hearing. The clinical signs and symptoms of this condition are as follows:

• Prelingual onset: This means that the hearing loss typically begins before a person can speak, usually at birth or in early childhood [1].
• Severe to profound deafness: Individuals with DFNB74 often experience severe to profound hearing loss affecting all frequencies [6].
• Stable hearing loss: The hearing loss associated with this condition is generally stable and does not worsen over time [7].

It's worth noting that autosomal recessive nonsyndromic deafness 74 is caused by a mutation in the MSRB3 gene, which is responsible for encoding an enzyme involved in the maturation of mitochondrial proteins [5]. This genetic defect leads to the development of hearing loss.

References:

[1] MD Venkatesh (2015) - The clinical spectrum may range from the lack of symptoms to vertigo and deafness. Autosomal recessive causes for NSHL. [5] A number sign (#) is used with this entry because autosomal recessive deafness-74 (DFNB74) is caused by homozygous mutation in the MSRB3 gene (613719) on chromosome 7p15. [6] LX Zhong (2013) - For example, autosomal recessive deafness typically presents as a congenital or prelingual, severe to profound deafness affecting all frequencies while ... [7] An autosomal recessive nonsyndromic deafness that is characterized by prelingual onset with usually severe to profound, stable hearing loss and has material ...

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

• Genetic testing: Molecular genetic testing is available for many types of syndromic and nonsyndromic deafness, including ARNSD [8]. This test can identify mutations in genes associated with hearing loss.
• GJB2 gene testing: The GJB2 gene is the most common cause of congenital severe-to-profound non-progressive sensorineural hearing loss. Genetic testing for the GJB2 gene can be performed to confirm a diagnosis of ARNSD [10].
• Parental carrier testing: If there's a family history of ARNSD, parental carrier testing should be offered to confirm that parents are carriers and that the risk of passing on the condition is understood [7].

It's essential to note that diagnostic tests for ARNSD may vary depending on individual circumstances. A healthcare professional can provide guidance on the most suitable tests based on a person's medical history and symptoms.

References:

[7] Autosomal recessive non-syndromic hearing loss​​ Parental carrier testing should be offered, where relevant, to confirm that parents are carriers and that the risk of passing on the condition is understood. [8] by RJH Smith · Cited by 240 — Diagnosis/testing. Molecular genetic testing, available in clinical laboratories for many types of syndromic and nonsyndromic deafness, plays a crucial role in diagnosing ARNSD. [10] GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL) is the most common genetic cause of congenital severe-to-profound non-progressive sensorineural hearing loss in many world populations.

Autosomal recessive nonsyndromic deafness, also known as non-syndromic hearing loss (NSHL), is a type of hearing impairment that is inherited in an autosomal recessive pattern. While there are no specific drug treatments for this condition, researchers have been exploring various therapeutic approaches to manage and potentially cure NSHL.

Current Treatment Options

Currently, the primary treatment options for NSHL include:

• Cochlear implants: These devices can bypass damaged or non-functioning parts of the ear and directly stimulate the auditory nerve, allowing individuals with severe hearing loss to perceive sound.
• Hearing aids: Amplifying sounds to help improve communication and speech recognition in individuals with mild to moderate hearing loss.

Emerging Therapies

Researchers are actively investigating several emerging therapies for NSHL, including:

• Gene therapy: This approach involves using viruses (such as adeno-associated virus, AAV) to deliver healthy copies of the deafness-causing gene to the inner ear. Gene therapy has shown promise in preclinical studies and is being explored in clinical trials.
• Stem cell therapy: Stem cells have the potential to differentiate into various cell types, including those found in the inner ear. Researchers are investigating the use of stem cells to repair or replace damaged auditory tissues.

Challenges and Future Directions

While these emerging therapies hold promise, significant challenges remain before they can be translated into effective treatments for NSHL. These include:

• Efficient gene delivery: Ensuring that genes are delivered efficiently and effectively to the target cells in the inner ear.
• Safety and efficacy: Conducting rigorous clinical trials to assess the safety and efficacy of these emerging therapies.

References

• [6] states that "current clinical treatments for HHL (hereditary hearing loss) are cochlear implants or hearing aids."
• [5] mentions that "more than 150 deafness genes have been recognized to be associated with HHL," highlighting the complexity of NSHL.
• [7] discusses gene therapy based on AAVs as a promising approach for treating hereditary deafness, but notes that significant challenges remain before it can become an effective clinical treatment.

Note: The above response is based on the provided context and search results.

Autosomal Recessive Nonsyndromic Deafness 74 (DFNB74) is a form of non-syndromic sensorineural deafness characterized by prelingual, bilateral, profound hearing loss. It results from mutations in the GJB2 gene on chromosome 13q12 [8].

To date, more than 700 different mutations have been identified in one of 42 genes in individuals with autosomal recessive nonsyndromic hearing loss (ARNSHL) [1]. Among these, GJB2-related AR NSHL is the most common genetic cause of congenital severe-to-profound hearing loss.

The differential diagnosis for DFNB74 involves considering other forms of non-syndromic sensorineural deafness. These include:

• Deafness, autosomal recessive 1a (DFNA1A), which is caused by mutations in the GJB2 gene on chromosome 13q12 [8].
• Other forms of autosomal recessive nonsyndromic hearing loss, such as those caused by mutations in the SLC26A4 or OTOF genes.
• Autosomal dominant loci, which are typically less severe and may involve different frequencies.

The diagnosis of DFNB74 is primarily based on genetic testing, including sequencing of the GJB2 gene. Audiological evaluation, including pure-tone audiometry and speech audiometry, can also provide important information for differential diagnosis [7].

It's worth noting that autosomal-recessive forms of deafness are generally the most severe and are almost exclusively caused by cochlear defects (sensorineural deafness), in contrast to autosomal-dominant loci which may involve different frequencies and are typically less severe [10].