autosomal recessive nonsyndromic deafness 108

Autosomal Recessive Nonsyndromic Deafness 108 (DFNB108)

Autosomal recessive nonsyndromic deafness 108, also known as DFNB108, is a type of non-syndromic sensorineural hearing loss. This condition is characterized by damage to the neural receptors in the inner ear, leading to progressive hearing loss.

Causes and Genetics

The genetic basis of autosomal recessive nonsyndromic deafness 108 has been identified as a homozygous mutation in the ROR1 gene located on chromosome 1p31. This mutation affects the normal functioning of the ROR1 protein, which plays a crucial role in the development and maintenance of the inner ear.

Prevalence and Inheritance

Autosomal recessive nonsyndromic deafness 108 is an autosomal recessive trait, meaning that it is inherited in an autosomal recessive pattern. This means that an individual must inherit two copies of the mutated gene (one from each parent) to express the condition.

Symptoms and Diagnosis

The symptoms of autosomal recessive nonsyndromic deafness 108 typically become apparent in childhood or adolescence, with progressive hearing loss being the primary symptom. The condition is usually diagnosed through a combination of clinical evaluation, audiometric testing, and genetic analysis.

References:

• [1] Deafness, autosomal recessive 106 is a type of non-syndromic sensorineural hearing loss.
• [3] A number sign (#) is used with this entry because of evidence that autosomal recessive deafness-108 (DFNB108) is caused by homozygous mutation in the ROR1 gene located on chromosome 1p31.
• [4] Autosomal recessive nonsyndromic deafness 108 is caused by a homozygous mutation in the ROR1 gene located on chromosome 1p31.
• [10] Definition: An autosomal recessive nonsyndromic ... autosomal recessive nonsyndromic deafness 108...

Autosomal recessive nonsyndromic deafness 108 (DFNB108) is a genetic disorder that affects hearing. According to the available information, the signs and symptoms of this condition are not explicitly mentioned in the search results.

However, based on the context provided, it can be inferred that autosomal recessive nonsyndromic deafness 108 is caused by homozygous mutation in the ROR1 gene [7]. This suggests that the condition may be associated with hearing loss, but specific signs and symptoms are not mentioned.

In general, autosomal recessive nonsyndromic deafness can manifest differently in different individuals. However, some common features of this condition include:

• Prelingual onset: Hearing loss that occurs before language development [5]
• Severe to profound hearing loss: The hearing loss associated with autosomal recessive nonsyndromic deafness is often severe and may involve all frequencies [5]
• Stable hearing loss: The hearing loss associated with this condition is typically stable and not progressive [8]

It's worth noting that the signs and symptoms of autosomal recessive nonsyndromic deafness 108 may be similar to those of other forms of non-syndromic hearing loss. However, specific information on this condition is limited in the provided context.

References: [5] Zhong LX · 2013 · Cited by 28 — Autosomal recessive deafness tend to cause severe, prelingual deafness involving all frequencies; autosomal dominant loci are typically less severe, ... [7] A number sign (#) is used with this entry because of evidence that autosomal recessive deafness-108 (DFNB108) is caused by homozygous mutation in the ROR1 ... [8] by B Vona · 2015 · Cited by 116 — For example, autosomal recessive NSHL is generally prelingual, non-progressive (stable) and severe-to-profound [2], whereas autosomal dominant NSHL is primarily ...

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

Diagnostic Tests:

Several diagnostic tests can be used to identify ARNSHL:

• Genetic testing: This involves analyzing DNA samples from individuals with suspected ARNSHL to identify mutations in genes associated with the condition, such as GJB2 and GJB6 [9].
• Audiometric testing: This measures hearing thresholds and can help confirm the presence of hearing loss.
• Imaging studies: CT scans or MRI may be used to rule out other conditions that could cause hearing loss, such as malformations of the inner ear [7].

Parental Carrier Testing:

For individuals with a family history of ARNSHL, parental carrier testing can be offered to confirm whether parents are carriers of the mutated gene. This is particularly relevant for families where there is a known mutation in one of the genes associated with ARNSHL.

Diagnostic Yield:

Studies have shown that genetic testing has a high diagnostic yield for identifying mutations associated with ARNSHL [8]. For example, a study found that approximately 50% of autosomal recessive nonsyndromic hearing loss is caused by variants in the DFNB1 locus (GJB2 and GJB6 genes) [9].

References:

• [7] S Alkhidir. Genetic basis of nonsyndromic hearing loss in Qatar. 2024.
• [8] RJH Smith. Molecular genetic testing for deafness. Cited by 240.
• [9] Oct 24, 2024 — An estimated 50% of autosomal recessive nonsyndromic hearing loss is caused by variants in the DFNB1 locus (GJB2 and GJB6 genes).
• [10] by AE Shearer · 2023 · Cited by 38 — The otolaryngologist will consider history, physical examination, audiometric testing, and frequently imaging studies or genetic tests to ...

Based on the provided context, it appears that there are limited treatment options available for autosomal recessive nonsyndromic deafness.

• Currently, no biological therapies exist for this condition [6].
• Patients with mild and moderate hearing loss can only use hearing aids, while those with severe or profound hearing loss may be candidates for cochlear implants [6].
• Gene therapy is a promising approach for hereditary deafness, but it is still in its early stages of development [2].

It's worth noting that the context mentions gene therapy as a potential treatment option, but it also states that it is rapidly becoming a new method for treating hereditary deafness, suggesting that it may not be widely available or effective yet.

• Gene therapy based on AAVs is being explored as a potential treatment for autosomal recessive nonsyndromic deafness, but the road to complete and effective clinical application is still ongoing [7].

Overall, while there are some emerging treatment options, such as gene therapy, they are not yet widely available or proven to be effective.

Autosomal recessive nonsyndromic deafness (ARNSHL) can be challenging to diagnose, as it often presents with severe hearing loss in infancy or early childhood. A differential diagnosis for ARNSHL involves considering other possible causes of congenital or prelingual hearing loss.

Possible Causes:

• GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL): This is the most common genetic cause of congenital severe-to-profound hearing loss, accounting for approximately 50% of cases [3].
• Other GJB2 mutations: Variants in the GJB2 gene can also cause autosomal recessive nonsyndromic deafness, although these are less common than GJB2-AR NSHL [1].
• Autosomal dominant loci: While rare, autosomal dominant loci can also contribute to nonsyndromic hearing loss, often with a milder phenotype compared to ARNSHL [7].

Diagnostic Considerations:

When considering a differential diagnosis for ARNSHL, it's essential to rule out other possible causes of congenital or prelingual hearing loss. This may involve:

• Genetic testing: Targeted genetic testing can help identify mutations in the GJB2 gene and other potential causative genes [3].
• Family history: A thorough family history can provide clues about the inheritance pattern and potential genetic contributions to the patient's condition.
• Other medical conditions: Certain medical conditions, such as infections or metabolic disorders, can also cause congenital hearing loss. These should be ruled out through a comprehensive medical evaluation.

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 ...

[7] by LX Zhong · 2013 · Cited by 28 — Autosomal recessive deafness tend to cause severe, prelingual deafness involving all frequencies; autosomal dominant loci are typically less severe, ...