autosomal recessive nonsyndromic deafness 115

Autosomal Recessive Nonsyndromic Deafness 115, also known as DFNB115, is a form of non-syndromic deafness characterized by severe sensorineural hearing impairment in early childhood. This condition results from damage to the inner ear, specifically the cochlea and auditory nerve, which affects the transmission of sound signals to the brain.

Causes and Symptoms

DFNB115 is caused by mutations in a specific gene that affects the development and function of the inner ear. The symptoms typically manifest in early childhood, with affected individuals experiencing severe hearing loss that can range from profound to moderate. This condition is inherited in an autosomal recessive pattern, meaning that both parents must be carriers of the mutated gene for their child to inherit the condition.

Prevalence and Diagnosis

The prevalence of DFNB115 varies among different populations, but it is considered a relatively rare form of non-syndromic deafness. The diagnosis of this condition typically involves genetic testing, which can identify the specific mutations responsible for the hearing loss. Audiological evaluations, such as pure-tone audiometry and speech audiometry, are also essential in assessing the extent of hearing impairment.

References

• [1] DFNB115 is a form of non-syndromic deafness characterized by severe sensorineural hearing impairment in early childhood.
• [2] This condition results from damage to the inner ear, specifically the cochlea and auditory nerve.
• [3] The symptoms typically manifest in early childhood, with affected individuals experiencing severe hearing loss that can range from profound to moderate.
• [4] DFNB115 is caused by mutations in a specific gene that affects the development and function of the inner ear.
• [5] This condition is inherited in an autosomal recessive pattern, meaning that both parents must be carriers of the mutated gene for their child to inherit the condition.

Autosomal recessive nonsyndromic deafness 115 (DFNB115) is a genetic disorder that affects hearing. The main clinical feature of this condition is severe to profound sensorineural hearing loss, which typically begins in early childhood.

Characteristics:

• Severe to profound sensorineural hearing loss
• Onset in early childhood, often prelingually
• Hearing loss can be stable and non-progressive

Other possible features:

• Moderate to severe intellectual deficit (in some cases)
• Congenital sensorineural hearing impairment
• Broad, stubby hands and feet (not a universal feature)

It's essential to note that the severity and progression of hearing loss can vary among individuals with DFNB115. A detailed medical evaluation by an audiologist or geneticist is necessary for accurate diagnosis and management.

References: [6] [7]

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

• Genetic testing: Genetic testing is the primary method for diagnosing ARNSHL. It involves analyzing DNA samples from individuals with suspected ARNSHL to identify mutations in genes associated with the condition, such as GJB2 [1][2].
• Newborn hearing screening (NBHS): NBHS is a common practice that can detect severe-to-profound hearing loss, including ARNSHL, in newborns. However, it may not always identify milder cases of ARNSHL [3].
• Audiological assessment: An audiological assessment involves testing an individual's hearing thresholds and speech recognition abilities to determine the extent of their hearing loss.
• Genetic counseling: Genetic counseling is essential for individuals with suspected ARNSHL, as it helps them understand the genetic basis of the condition, the risks of passing it on to offspring, and the implications for family members.

It's worth noting that a combination of these diagnostic tests can provide a comprehensive understanding of an individual's hearing loss and help guide treatment decisions.

References:

[1] GJB2-AR NSHL is established in a proband with suggestive findings and confirmed by genetic testing [10].

[2] Genetic testing for ARNSHL typically involves analyzing DNA samples from individuals with suspected ARNSHL to identify mutations in genes associated with the condition, such as GJB2 [4].

[3] NBHS can detect severe-to-profound hearing loss, including ARNSHL, but may not always identify milder cases of ARNSHL [5].

Current Therapies for Autosomal Recessive Nonsyndromic Deafness

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

• Hearing aids: These can be fitted between the ages of 10 and 40 to assist with sound amplification [3].
• Cochlear implants: These can also be used to restore hearing in individuals with severe or profound hearing loss [6].

It's worth noting that gene therapy is an area of active research, and several preclinical studies have investigated its potential to rescue hearing loss in mouse models with mutations in TMC1 (DFNB7 and DFNB11) [7]. However, these findings are still preliminary, and more research is needed before any potential treatments can be developed.

Gene Therapy on the Horizon

Recent advances in gene therapy have shown promise for treating genetic hearing loss. A study published in 2024 found that AAV1-hOTOF binaural gene therapy was feasible, safe, and efficacious for patients with DFNB9 [2]. This suggests that gene therapy may be a potential treatment option for autosomal recessive nonsyndromic deafness in the future.

Consulting 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 situation [9].

References:

[1] Not applicable (no relevant information found)

[2] by H Wang · 2024 · Cited by 12

[3] by RJH Smith · 2018 · Cited by 18

[6] Aug 31, 2022

[7] by D Brotto · 2024

[9] Please consult with a healthcare professional for medical advice and treatment.

Differential Diagnosis of Autosomal Recessive Nonsyndromic Deafness

Autosomal recessive nonsyndromic deafness (ARNSHL) is a form of hearing loss that is inherited in an autosomal recessive manner, meaning that it requires mutations in both copies of the gene to manifest. The differential diagnosis for ARNSHL involves identifying other genetic conditions that may present with similar symptoms.

Common Causes of ARNSHL

• GJB2-related deafness: This is the most common cause of congenital severe-to-profound non-progressive sensorineural hearing loss in many world populations [10].
• STRC-related autosomal recessive hearing loss: This condition comprises both nonsyndromic sensorineural hearing loss and sensorineural hearing loss with decreased fertility in males who have biallelic contiguous gene deletions involving STRC and CATSPER2 [11].

Other Genetic Conditions to Consider

• Usher Syndrome: A genetic disorder that causes progressive vision and hearing loss, inherited in an autosomal recessive manner [4].
• Deafness, autosomal recessive 1a: A form of non-syndromic sensorineural hearing loss caused by mutations in the GJB2 gene on chromosome 13q12 [3].

Diagnostic Approach

A stepwise diagnostic approach is recommended for the genetic testing of nonsyndromic hearing loss, which includes a molecular diagnosis spectrum of 92 non-syndromic hearing loss patients [12]. This approach can help identify the underlying cause of ARNSHL and guide treatment decisions.

In conclusion, differential diagnosis of autosomal recessive nonsyndromic deafness involves considering other genetic conditions that may present with similar symptoms. A thorough diagnostic approach is essential to identify the underlying cause of ARNSHL and provide appropriate treatment recommendations.

References: [3] Deafness, autosomal recessive 1a [4] Usher Syndrome [10] GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL) [11] STRC-related autosomal recessive hearing loss (STRC-HL) [12] Molecular diagnosis spectrum of 92 non-syndromic hearing loss patients