autosomal recessive nonsyndromic deafness 55

Autosomal Recessive Nonsyndromic Deafness 55 (DFNB55)

Autosomal recessive nonsyndromic deafness 55, also known as DFNB55, is a genetic condition characterized by nonsyndromic deafness, which means that it affects hearing only and is not associated with other signs or symptoms.

Causes

The material basis of this condition lies in variations in the chromosome region 4q12-q13.2. This suggests that mutations or changes in genes located in this region are responsible for causing DFNB55.

Prevalence

While specific prevalence data is not available, nonsyndromic deafness, including DFNB55, affects approximately 1 in 1000 newborn children, indicating a relatively rare condition.

Inheritance Pattern

DFNB55 follows an autosomal recessive inheritance pattern, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to express the condition. Carriers, who have one copy of the mutated gene, are generally asymptomatic but can pass the mutation to their offspring.

References

• [1] - A clinical resource describes DFNB55 as a genetic condition characterized by nonsyndromic deafness caused by variations in the chromosome region 4q12-q13.2.
• [3] - This condition is also known as autosomal recessive nonsyndromic deafness that has material basis in variation in the chromosome region 4q12-q13.2.
• [10] - The Disease Ontology Definition further confirms that DFNB55 is an autosomal recessive nonsyndromic deafness with a material basis in variation in the chromosome region 4q12-q13.2.

Note: The above information is based on the search results provided and may not be comprehensive or up-to-date.

Autosomal recessive nonsyndromic deafness, also known as congenital or prelingual deafness, is characterized by severe to profound hearing loss that affects all frequencies. This type of deafness typically presents at birth or before speech development.

Common signs and symptoms:

• Severe to profound hearing loss: The most common symptom of autosomal recessive nonsyndromic deafness is a significant reduction in hearing ability, often affecting all frequencies.
• Prelingual onset: Deafness typically begins before speech development, meaning that individuals with this condition may not be able to hear or understand spoken language from an early age.
• Stable hearing loss: The hearing loss associated with autosomal recessive nonsyndromic deafness is often stable and does not fluctuate over time.

Other potential symptoms:

• Dysphagia (difficulty swallowing)
• Abnormal electroretinogram
• Cerebral visual impairment
• Constriction of peripheral visual field
• Myopia (nearsightedness)
• Reduced visual acuity

It's essential to note that not all individuals with autosomal recessive nonsyndromic deafness will exhibit these symptoms, and the severity of the condition can vary from person to person.

References:

[6] - This type of deafness is characterized by prelingual onset with usually stable hearing loss and has material basis in mutation in genes such as GJB2. [10] - An autosomal recessive nonsyndromic deafness that is characterized by prelingual onset with usually severe to profound, stable hearing loss and has material basis in mutation in genes such as GJB2.

Autosomal Recessive Nonsyndromic Deafness (ARNSD) 55, also known as Connexin 26 deafness, is a genetic disorder that affects the inner ear and leads to hearing loss. Diagnostic testing for ARNSD 55 typically involves genetic analysis to identify mutations in the GJB2 gene.

Genetic Testing

• Targeted Familial Testing: This test is recommended for patients with a family history of hearing loss [5]. The diagnostic yield for this test was found to be 60% in one study.
• Gene Panel Testing: This test involves analyzing multiple genes associated with hearing loss, including GJB2. The diagnostic yield for gene panel testing was found to be 50% in another study [5].

Other Diagnostic Tests

While genetic testing is the primary method of diagnosis for ARNSD 55, other tests may also be performed to rule out other conditions that can cause hearing loss.

• Mitochondrial Genome Analysis: This test may be performed to identify mutations in the mitochondrial genome, which can also cause hearing loss [3].
• Clinical Evaluation: A thorough clinical evaluation is essential to determine the presence and severity of hearing loss, as well as any associated symptoms or conditions.

Benefits of Genetic Testing

Genetic testing for ARNSD 55 provides several benefits, including:

• Accurate determination of the etiology of the patient's hearing loss
• Identification of family members who may be at risk of developing the condition
• Early diagnosis and treatment planning

It is essential to consult with a genetic counselor or a healthcare professional experienced in genetic testing for ARNSD 55 to determine the best course of action for diagnostic testing.

References:

[1] Recent clinical studies. Diagnosis. Three novel GJB2 (connexin 26) variants associated with autosomal dominant syndromic and nonsyndromic hearing loss. [3] Clinical resource with information about Autosomal recessive nonsyndromic hearing loss 55 and its clinical features, available genetic tests from US and ... [5] by S Alkhidir · 2024 — The diagnostic yield for targeted familial testing was 60% (n = 3 patients) and for gene panel was 50% (n = 5). Thus, we recommend using GJB2 ...

Current Therapies for Autosomal Recessive Nonsyndromic Deafness

Unfortunately, there are no biological therapies available to treat autosomal recessive nonsyndromic deafness. The current treatment options for this condition are limited to:

• Hearing aids: These can be fitted to assist with sound amplification between the ages of 10 and 40 [5].
• Cochlear implants: These can also be used to improve hearing, but they may not restore normal hearing [6].

It's worth noting that gene therapy is being researched as a potential treatment for certain forms of autosomal recessive nonsyndromic deafness. For example, a study on AAV1-hOTOF binaural gene therapy has shown promising results in patients with DFNB9 [2]. However, this is still an emerging area of research and more studies are needed to confirm its efficacy.

Consultation with a Healthcare Professional

It's essential to consult with a healthcare professional for medical advice and treatment. They can provide personalized guidance on the best course of action for your specific condition [9][10].

References:

[2] by H Wang · 2024 · Cited by 12 [5] by RJH Smith · 2018 · Cited by 18 [6] Aug 31, 2022 [9] Please consult with a healthcare professional for medical advice and treatment. Print. Disease Overview. [10] Please consult with a healthcare professional for medical advice and treatment. Print. Disease Overview.

Autosomal recessive nonsyndromic deafness (ARNSHL) can be challenging to diagnose, and a differential diagnosis is often necessary to rule out other conditions that may present with similar symptoms. Here are some key points to consider:

• GJB2-related ARNSHL: This is the most common genetic cause of congenital severe-to-profound bilateral deafness (result 2). Mutations in the GJB2 gene can lead to hearing loss, and a differential diagnosis should include testing for this mutation.
• OTOF-related ANSD: This condition is characterized by congenital or prelingual severe-to-profound bilateral deafness without inner-ear anomalies on MRI or CT (result 3). A differential diagnosis should also consider OTOF-related ANSD, especially if the patient has a family history of hearing loss.
• Other genetic causes: ARNSHL can be caused by mutations in other genes, such as those involved in the auditory system (results 1 and 4). A differential diagnosis should include testing for these potential genetic causes.
• Non-syndromic deafness: This is a partial or total loss of hearing that is not associated with other pathologies (result 5). While it's not directly related to ARNSHL, a differential diagnosis should consider non-syndromic deafness as a possible cause of hearing loss.
• Autosomal dominant loci: These can also cause hearing loss, although they are typically less severe than autosomal recessive loci (result 7). A differential diagnosis should include testing for these potential causes.

To make an accurate and directed diagnosis, the Igenomix Syndromic and Nonsyndromic Deafness Precision Panel can be used (result 8). This panel can help identify the underlying genetic cause of hearing loss and guide further testing or treatment.

References:

• Result 2: GJB2-related autosomal recessive nonsyndromic hearing loss is the most common genetic cause of congenital severe-to-profound bilateral deafness.
• Result 3: OTOF-related ANSD is characterized by congenital or prelingual severe-to-profound bilateral deafness without inner-ear anomalies on MRI or CT.
• Result 4: Autosomal recessive nonsyndromic deafness can be caused by mutations in other genes, such as those involved in the auditory system.
• Result 5: Non-syndromic deafness is a partial or total loss of hearing that is not associated with other pathologies.
• Result 7: Autosomal dominant loci can also cause hearing loss, although they are typically less severe than autosomal recessive loci.
• Result 8: The Igenomix Syndromic and Nonsyndromic Deafness Precision Panel can be used to make an accurate and directed diagnosis as well as a differential diagnosis of hereditary hearing loss.