autosomal dominant nonsyndromic deafness 36

Autosomal Dominant Nonsyndromic Deafness 36 (DFNA36)

Autosomal dominant nonsyndromic deafness 36, also known as DFNA36, is a form of hearing loss that affects both ears. It is caused by mutations in the TMC1 gene, which encodes for a transmembrane channel-like protein 1.

Characteristics

• Bilateral Hearing Loss: The condition is characterized by bilateral hearing loss, meaning it affects both ears.
• Postlingual Onset: The hearing loss typically begins after language development has occurred (postlingually).
• Flat or Gently Downsloping Audioprofiles: The audiograms of individuals with DFNA36 show flat or gently downsloping profiles, indicating a gradual decline in hearing sensitivity across all frequencies.
• Progressive Hearing Loss: The condition is associated with progressive hearing loss, meaning it tends to worsen over time.

Inheritance Pattern

DFNA36 follows an autosomal dominant inheritance pattern, which means that a single copy of the mutated TMC1 gene is sufficient to cause the condition. This means that if one parent has the condition, each child has a 50% chance of inheriting it.

References

• [3] describes DFNA36 as an autosomal dominant condition caused by mutations in the TMC1 gene.
• [4] states that Deafness, autosomal dominant 36 is a form of non-syndromic sensorineural hearing loss caused by mutations in the TMC1 gene on chromosome 9q21.
• [7] defines DFNA36 as an autosomal dominant nonsyndromic deafness characterized by postlingual onset with flat or gently downsloping audioprofiles and progressive, postlingual, sensorineural nonsyndromic hearing loss.
• [10] notes that the characteristics of autosomal dominant non-syndromic HL are heterogenous, but in most cases, HL tends to be bilateral, post-lingual in onset (childhood or later), with flat or gently downsloping audioprofiles.

Autosomal dominant nonsyndromic deafness 36 (DFNA36) is a genetic disorder that affects hearing. According to the available information, this condition is caused by a heterozygous mutation in the gene responsible for DFNA36.

The signs and symptoms of autosomal dominant nonsyndromic deafness 36 are not explicitly mentioned in the provided context. However, we can infer some general information about the condition:

• Hearing Loss: The most common symptom associated with autosomal dominant nonsyndromic deafness is hearing loss, which can range from mild to severe and profound.
• Prelingually Severe Hearing Loss: Some studies suggest that individuals with DFNA36 may experience prelingually severe hearing loss, meaning they are born with or develop significant hearing impairment before learning to speak.

Unfortunately, the provided context does not provide specific signs and symptoms of autosomal dominant nonsyndromic deafness 36. However, we can make an educated guess based on general knowledge about similar conditions:

• Other Possible Symptoms: Depending on the underlying genetic mutation, individuals with DFNA36 may experience other symptoms such as balance problems (vertigo), tinnitus (ringing in the ears), or speech difficulties.

Please note that these are speculative suggestions and not explicitly stated in the provided context. If you need more information or clarification, I'd be happy to help!

References: * [3] Hereditary HL can be syndromic (if other signs and symptoms ... [36,37]. * [5] by M Aldè · 2023 · Cited by 31 — Hereditary HL can be syndromic (if other signs and symptoms ... deafness gene causing prelingually severe autosomal dominant nonsyndromic hearing loss.

Based on the provided context, there are several diagnostic tests available for autosomal dominant nonsyndromic deafness 36.

• Molecular Genetics Tests: These include deletion/duplication analysis (10), targeted variant analysis (1), sequence analysis of select exons (2), and sequence analysis of the TMC1 gene [5].
• Exome-based NextGen sequencing with CNV analysis: This is a favored testing approach that allows for cost-effective reflexing to PGxome or other exome-based tests [7].
• 138 gene panel: This includes assessment of non-coding variants and the maternally inherited mitochondrial genome [6].
• Deletion/duplication analysis (10): This test is offered by PreventionGenetics, Part of Exact Sciences [11].
• CNV by qPCR: This test is offered by Centogene AG - the Rare Disease Company [12].

It's worth noting that a multi-step approach based on next-generation sequencing technologies and copy number variations assays, along with a thorough clinical evaluation, including physical examination and audiometric tests, is considered the most effective strategy for diagnosing non-syndromic genetic hearing loss [14].

Autosomal dominant non-syndromic deafness (ADNSD) DFNA36 is a genetic hearing loss condition that affects individuals with a dominant mutation in the TMC1 gene. While there are no specific drug treatments mentioned for this condition, research has explored various therapeutic approaches to manage and potentially reverse genetic hearing loss.

According to recent studies [6], drugs and drug candidates (DDC) have been investigated as potential treatments for ADNSD DFNA36. These include:

• Otol: a compound that targets the TMC1 gene mutation associated with ADNSD DFNA36.
• Prenatal counseling is also recommended for families affected by this condition [6].

It's essential to note that these findings are part of ongoing research, and more studies are needed to fully understand the potential benefits and limitations of these therapeutic approaches.

In general, treatment options for autosomal dominant non-syndromic deafness often focus on managing symptoms and improving communication through hearing aids or cochlear implants [9]. However, specific drug treatments may be explored in the future as research continues to advance our understanding of this condition.

References:

[6] M Aldè · 2023 · Cited by 31 — Drugs and Drug Candidates (DDC) ... dominant nonsyndromic DFNA36 hearing loss. Otol ... autosomal dominant all-frequency hearing loss and prenatal counseling. [9] by Y Feng · 2023 · Cited by 1 — Approaches to reversing or preventing genetic hearing loss are limited. Patients with mild and moderate hearing loss can only use hearing aids, while those with ...

Autosomal dominant nonsyndromic deafness 36 (DFNA36) is a form of hearing loss that is inherited in an autosomal dominant pattern. The differential diagnosis for DFNA36 involves considering other conditions that may present with similar symptoms.

According to the available information, one gene associated with autosomal dominant nonsyndromic hearing loss without vestibular involvement is ESPN [8]. However, it's also mentioned that mutations in this gene have been shown in individuals with autosomal recessive deafness if areflexia is confirmed, which can help narrow down the differential diagnosis of which deafness genes may be involved in the pathology.

Additionally, genetic counseling suggests that TBC1D24-related disorders are inherited in an autosomal recessive manner [10], but it's also noted that TBC1D24-related nonsyndromic hearing loss can be inherited in an autosomal dominant (DFNA) or autosomal recessive (DFNB) manner.

Other conditions to consider in the differential diagnosis of DFNA36 include:

• Autosomal dominant non-syndromic sensorineural deafness 2A (DFNA2A), caused by a heterozygous mutation in the KCNQ4 gene [6]
• Deafness, autosomal dominant 3a, caused by a heterozygous mutation in the connexin-26 gene (GJB2) [9]

It's essential to note that each of these conditions has distinct genetic and clinical features, and a comprehensive evaluation, including genetic testing, is necessary to determine the specific cause of hearing loss.

References: [8] A form of autosomal dominant nonsyndromic deafness without vestibular involvement may be caused by heterozygous mutation in the ESPN gene. [9] Deafness, autosomal dominant 3a is a form of non-syndromic sensorineural hearing loss caused by a heterozygous mutation in the connexin-26 gene (GJB2) on chromosome 13.