autosomal dominant nonsyndromic deafness 74

Autosomal dominant nonsyndromic deafness 74 (DFNA74) is a form of hearing loss that is characterized by progressive, postlingual hearing impairment with onset in the third decade of life [1, 2, 5]. This means that individuals affected by DFNA74 typically experience a gradual decline in their hearing abilities after they have already developed language skills.

The condition is caused by a heterozygous mutation in the PDE1C gene located on chromosome 7p14.3 [4, 7, 8, 9]. This genetic mutation leads to the development of nonsyndromic postlingual progressive hearing loss, which is distinct from other forms of hearing loss that may be associated with syndromes or other medical conditions.

In most cases, DFNA74 affects individuals bilaterally, meaning that both ears are affected by the condition [6]. The hearing impairment associated with DFNA74 tends to be high-frequency and mid-frequency in nature, although the exact pattern of hearing loss can vary from person to person.

It's worth noting that autosomal dominant nonsyndromic deafness 74 is a relatively rare form of hearing loss, and more research is needed to fully understand its characteristics and implications for affected individuals.

Autosomal dominant nonsyndromic deafness 74 (DFNA74) is characterized by nonsyndromic postlingual progressive hearing loss, with onset in the third decade of life [4]. This means that individuals with DFNA74 typically experience a gradual decline in their hearing ability after they have learned to speak and understand language.

The symptoms of DFNA74 are primarily related to hearing loss, which can range from mild to profound degrees of impairment. The hearing loss may be stable or progressive, meaning that it can change over time [12]. In some cases, the hearing loss may be limited to high frequencies, while in others, it may affect middle and high frequencies as well [3].

It's worth noting that DFNA74 is a form of non-syndromic hearing loss, which means that it does not occur with other signs and symptoms affecting other parts of the body. This distinguishes it from syndromic hearing loss, where hearing loss occurs in addition to other clinical manifestations.

In terms of specific signs and symptoms, there are no distinct features associated with DFNA74 beyond the progressive hearing loss itself. The condition is typically diagnosed based on a combination of medical history, physical examination, and audiometric testing [13].

References: [3] by M Aldè · 2023 · Cited by 31 — HL is generally diagnosed between 5 and 15 years old and is initially limited to high frequencies, with later involvement of the middle and high ... [4] Oct 2, 2018 — Autosomal dominant deafness-74 (DFNA74) is characterized by nonsyndromic postlingual progressive hearing loss, with onset in the third ... [12] Hearing loss can affect one (unilateral) or both (bilateral) ears and can range from mild to profound degrees of hearing loss. The hearing loss may also be stable or progressive, meaning that it can change over time. Non-syndromic hearing loss is inherited in one of the following patterns: Autosomal recessive; Autosomal dominant; X-linked ... [13] Hereditary hearing loss can be classified into syndromic and non syndromic hearing loss. 3 Syndromic hearing loss includes more than 400 syndromes in which hearing loss occurs in addition to other signs and symptoms. 4 Non syndromic hearing loss (NSHL) can be inherited in an autosomal recessive manner (75–80%), autosomal dominant pattern (20 ...

Autosomal dominant nonsyndromic deafness (ADNSHL) can be diagnosed through various genetic tests, which are crucial for identifying the underlying cause of hearing loss in individuals and families affected by this condition.

• Molecular Genetic Testing: This is a key diagnostic tool for ADNSHL. Molecular genetic testing involves analyzing DNA samples to identify mutations in specific genes associated with ADNSHL (Smith RJH, 2018 [7]). The test can be performed on blood or tissue samples.
• Exome Sequencing: Exome sequencing is a comprehensive genetic test that examines the protein-coding regions of the genome (Smith RJH, 2018 [2]). It is often used to identify mutations in genes associated with ADNSHL.
• Genome Sequencing: Genome sequencing involves analyzing the entire DNA sequence of an individual. This test can be used to identify rare or novel mutations in genes associated with ADNSHL (Smith RJH, 2018 [2]).
• Exome Array: An exome array is a genetic test that examines specific regions of the genome associated with hearing loss. It may be considered if exome sequencing is not available or feasible (Smith RJH, 2018 [2]).

It's essential to note that diagnosis and testing for ADNSHL require expertise in genetics and dysmorphology. A comprehensive evaluation by a qualified healthcare professional is necessary to determine the best course of action for each individual case (Alkhidir S, 2024 [8]).

Based on the provided context, it appears that there are currently no specific drug treatments available for autosomal dominant nonsyndromic deafness.

However, researchers are exploring gene therapy as a potential treatment option. Gene replacement, in particular, has shown promise in treating genetic diseases, including those caused by autosomal dominant inheritance (see [14]).

Additionally, adeno-associated virus (AAV)-mediated editing is being investigated for its potential to treat human autosomal dominant hearing loss (see [13]). This approach involves using AAV to deliver a healthy copy of the gene responsible for the hearing loss, which can help restore normal hearing function.

It's worth noting that these emerging treatments are still in the early stages of research and have not yet been widely tested or approved for use in humans. Further studies are needed to determine their safety and efficacy (see [6]).

Key points:

• Currently, there is no specific drug treatment available for autosomal dominant nonsyndromic deafness.
• Gene

Autosomal dominant nonsyndromic deafness (ADNSHL) can be challenging to diagnose, as it presents with a wide range of hearing loss severities and ages of onset. However, there are several key factors that can help in the differential diagnosis of ADNSHL.

Key Diagnostic Features:

• Family History: A positive family history is a crucial factor in diagnosing ADNSHL. Most individuals with ADNSHL have a parent or sibling with hearing loss.
• Age of Onset: ADNSHL typically presents with early onset, often before the age of 10-15 years.
• Bilateral Hearing Loss: Bilateral hearing loss is a hallmark of ADNSHL, although unilateral cases can occur.
• Progressive Hearing Loss: The hearing loss in ADNSHL is usually progressive, meaning it worsens over time.

Genetic Considerations:

• KCNQ4 Gene: Mutations in the KCNQ4 gene are a common cause of ADNSHL, particularly in families with a history of early-onset hearing loss.
• TECTA and MYO6 Genes: Mutations in the TECTA and MYO6 genes have also been associated with ADNSHL.

Other Conditions to Consider:

• Autosomal Recessive Hearing Loss: While less common, autosomal recessive hearing loss should be considered in cases where there is a family history of hearing loss on both sides.
• X-linked Hearing Loss: X-linked hearing loss can also present with early-onset hearing loss and should be ruled out.

Diagnostic Testing:

• Genetic Testing: Genetic testing for the KCNQ4, TECTA, and MYO6 genes is recommended in cases where ADNSHL is suspected.
• Auditory Profiling: Auditory profiling can help identify characteristic patterns of hearing loss associated with ADNSHL.

In conclusion, differential diagnosis of autosomal dominant nonsyndromic deafness requires a thorough evaluation of family history, age of onset, bilateral hearing loss, and progressive nature of the condition. Genetic testing for KCNQ4, TECTA, and MYO6 genes can also aid in the diagnosis. [1][2][3][4][5]