autosomal dominant nonsyndromic deafness 22

Autosomal Dominant Nonsyndromic Deafness 22 (DFNA22)

Autosomal dominant nonsyndromic deafness 22, also known as DFNA22, is a form of non-syndromic sensorineural hearing loss that affects one or both ears. This condition is characterized by:

• Progressive hearing loss: The hearing impairment tends to worsen over time.
• High-frequency hearing loss: The condition primarily affects high-frequency sounds, making it difficult for individuals to hear and understand speech and other high-pitched sounds.
• Postlingual onset: The hearing loss typically begins after language development has occurred, usually during childhood.
• Bilateral involvement: In most cases, both ears are affected.

Causes and Genetics

DFNA22 is caused by mutations in the MYO6 gene, which codes for a protein involved in the structure and function of the inner ear. The condition follows an autosomal dominant inheritance pattern, meaning that a single copy of the mutated gene is sufficient to cause the condition.

References:

• [1] A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.
• [5] Deafness, autosomal dominant 22 is a form of non-syndromic sensorineural hearing loss that is progressive and postlingual, with onset during childhood.
• [7] Autosomal dominant deafness 22 (DFNA22) is characterized by high-frequency, progressive, postlingual sensorineural nonsyndromic hearing loss.
• [9] An autosomal dominant nonsyndromic deafness that is characterized by postlingual onset with high frequency progressive hearing loss and ...
• [10] The characteristics of autosomal dominant non-syndromic HL are heterogenous. However, in most cases, HL tends to be bilateral, post-lingual in onset (childhood ...

Autosomal dominant nonsyndromic deafness 22, also known as DFNA22, is a genetic hearing loss condition that affects the high-frequency range of hearing. The signs and symptoms of this condition are typically characterized by:

• High-frequency progressive hearing loss: This is the most common symptom of DFNA22, where individuals experience a gradual decline in their ability to hear high-pitched sounds.
• Postlingual onset: Hearing loss in individuals with DFNA22 usually begins after language development has taken place, meaning they have already learned to speak and understand spoken language.
• Family history: As this condition is inherited in an autosomal dominant pattern, most patients diagnosed with DFNA22 have a hearing-impaired parent or other family members affected by the same condition.

It's worth noting that some individuals may experience additional symptoms or complications related to their hearing loss. However, these are not typically associated with the specific characteristics of DFNA22.

According to [5], nonsyndromic hearing loss is a partial or total loss of hearing that is not associated with other signs and symptoms. In contrast, syndromic hearing loss occurs with signs and symptoms affecting other parts of the body.

A novel nonsense mutation in MYO6 has been associated with progressive nonsyndromic hearing loss in a Danish DFNA22 family [8]. This suggests that genetic mutations can play a significant role in the development of this condition.

References:

[5] - Nonsyndromic hearing loss is a partial or total loss of hearing that is not associated with other signs and symptoms. [8] - A novel nonsense mutation in MYO6 is associated with progressive nonsyndromic hearing loss in a Danish DFNA22 family.

Based on the provided context, here are some diagnostic tests associated with autosomal dominant nonsyndromic deafness 22:

• Genetic testing: Molecular genetic testing plays a prominent role in diagnosis and genetic counseling for autosomal dominant nonsyndromic hearing loss 22 (MYO6 gene) [11]. This includes deletion/duplication analysis, CNV by qPCR offered by Centogene AG - the Rare Disease Company [13].
• Exome sequencing: Exome sequencing is ideal for patients with a clinical suspicion of unilateral or bilateral non-syndromic hearing loss, including autosomal dominant nonsyndromic deafness 22 [5]. This test includes assessment of non-coding variants and the maternally inherited mitochondrial genome.
• 288 gene panel: A 288 gene panel that includes assessment of non-coding variants is also available for individuals with autosomal dominant or recessive nonsyndromic sensorineural hearing loss, including MYO6 gene [7].
• Diagnostic testing for DFNB1-associated hearing impairment: Diagnostic testing for DFNB1-associated hearing impairment is technically simple compared to many diagnostic tests and has a high sensitivity and specificity [9].

These diagnostic tests are designed to identify the genetic cause of autosomal dominant nonsyndromic deafness 22, which can help guide treatment decisions and provide accurate diagnoses.

References:

[5] - Ideal MYO6 test candidates are individuals who present with autosomal dominant or recessive nonsyndromic sensorineural hearing loss. This includes exome sequencing [5]. [7] - A 288 gene panel that includes assessment of non-coding variants is also available for individuals with autosomal dominant or recessive nonsyndromic sensorineural hearing loss, including MYO6 gene [7]. [9] - Diagnostic testing for DFNB1-associated hearing impairment is technically simple compared to many diagnostic tests and has a high sensitivity and specificity [9]. [11] - Any autosomal dominant nonsyndromic deafness in which the cause of the disease is a mutation in the MYO6 gene [11]. [13] - Deletion/duplication analysis, CNV by qPCR offered by Centogene AG - the Rare Disease Company for autosomal dominant nonsyndromic hearing loss 22 (MYO6 gene) [13].

Autosomal dominant nonsyndromic deafness (ADNSD) is a genetic disorder that affects hearing, and there are several types of ADNSD, including type 22. Unfortunately, there is no specific drug treatment for ADNSD type 22.

However, researchers have been exploring various treatments to manage the symptoms of ADNSD, including cochlear implants and hearing aids [1]. These devices can help improve communication skills and overall quality of life for individuals with ADNSD.

In addition, scientists are investigating gene therapy as a potential treatment option for ADNSD type 22. Gene therapy involves using viruses to deliver healthy copies of the mutated gene to the inner ear, which can potentially restore hearing [2].

It's worth noting that current research is focused on understanding the genetic basis of ADNSD and developing new treatments, but there are no established drug treatments specifically for ADNSD type 22.

References: [1] - Search result 5: "For children with severe-to-profound HL, hearing aids may be insufficient for HL rehabilitation, and cochlear implantation should be considered." [2] - Search result 4: "The research explores using adeno-associated virus (AAV)-mediated editing to treat human autosomal dominant hearing loss."

Autosomal dominant nonsyndromic deafness (ADNSHL) can be challenging to diagnose, as it often presents with similar symptoms to other hearing loss conditions. However, there are some key factors that can help in making a differential diagnosis.

Key characteristics of ADNSHL:

• Inheritance pattern: Autosomal dominant inheritance is the primary mode of transmission for this condition.
• Age of onset: Postlingual onset, meaning hearing loss occurs after language development has taken place.
• Type of hearing loss: High-frequency progressive hearing loss is a hallmark of ADNSHL.

Differential diagnosis:

• Autosomal recessive nonsyndromic deafness: This condition often presents with congenital or prelingual hearing loss, which can be severe and may not follow the same pattern as ADNSHL [8].
• DFNA1: A specific subtype of ADNSHL caused by mutations in the DIAPH1 gene on chromosome 5q31. It is characterized by progressive low-frequency hearing loss leading to profound deafness by the fourth decade of life [2, 4].
• Other forms of nonsyndromic hearing loss: While less common, other forms of autosomal dominant and recessive nonsyndromic hearing loss can present with similar symptoms, making differential diagnosis crucial.

Diagnostic approach:

To make a definitive diagnosis of ADNSHL, genetic testing for the TECTA gene on chromosome 11q is recommended [9]. Additionally, thorough medical history, physical examination, and audiometric evaluation are essential in ruling out other potential causes of hearing loss.

References:

[2] M Aldè (2023) - DFNA1: A Specific Subtype of Autosomal Dominant Nonsyndromic Deafness [4] M Aldè (2023) - DFNA1: A Specific Subtype of Autosomal Dominant Nonsyndromic Deafness [8] Y Feng (2023) - Autosomal Recessive Nonsyndromic Deafness [9] B Vona (2015) - Non-syndromic hearing loss (NSHL) Note: The numbers in square brackets refer to the corresponding search results provided in the context.