autosomal recessive nonsyndromic deafness 27

Autosomal recessive nonsyndromic deafness 27 (ADNF27) is a genetic condition characterized by nonsyndromic deafness caused by variations in the chromosome region 2q23-q31 [3]. This form of hearing loss is inherited in an autosomal recessive pattern, meaning that a person must inherit two copies of the mutated gene (one from each parent) to express the condition.

The symptoms of ADNF27 typically include postlingual progressive moderate to profound sensorineural hearing loss [5][6]. This means that individuals with this condition may experience a gradual decline in their hearing ability, starting after they have acquired language skills. The degree of hearing loss can vary from mild to profound.

It's worth noting that autosomal dominant forms of nonsyndromic deafness are characterized by very early onset and bilateral hearing loss with varying degrees of severity [8]. However, ADNF27 is specifically associated with variations in the chromosome region 2q23-q31.

In terms of clinical features, individuals with ADNF27 may experience a range of symptoms related to their hearing loss. These can include difficulty understanding speech, especially in noisy environments, and a need for amplification devices such as hearing aids or cochlear implants [7].

Overall, autosomal recessive nonsyndromic deafness 27 is a genetic condition that affects an individual's ability to hear, with symptoms ranging from mild to profound sensorineural hearing loss.

References: [3] - Context result 3 [5] - Context result 5 [6] - Context result 6 [7] - Context result 7 [8] - Context result 8

Autosomal Recessive Nonsyndromic Deafness 27 (DFNB27) is a genetic disorder characterized by progressive hearing loss. The signs and symptoms of this condition are as follows:

• Postlingual progressive moderate to profound sensorineural hearing loss: This means that the hearing loss typically occurs after language development has taken place, and it progresses over time, leading to moderate to severe hearing impairment [7].
• Limited to low frequencies (2000 Hz and below): The hearing loss in DFNB27 is primarily confined to low-frequency sounds, which can make everyday conversations and communication more challenging [8].

It's essential to note that the symptoms of autosomal recessive nonsyndromic deafness 27 may vary from person to person, and not everyone with this condition will experience all of these signs and symptoms. If you're looking for more information on this topic or would like to know about treatment options, please let me know.

References: [7] - [8]

Autosomal recessive nonsyndromic deafness 27, also known as DFNB1-associated hearing impairment, is a form of non-syndromic sensorineural hearing loss. Diagnostic testing for this condition involves evaluating genetic variations that affect the GJB2 gene on chromosome 13q12.

Diagnostic Tests:

• Genetic testing to identify mutations in the GJB2 gene [7]
• Chromosomal analysis to confirm the presence of a variation in the chromosome region 2q23-q31 [2]

These tests are typically recommended for patients with a clinical suspicion of unilateral or bilateral non-syndromic hearing loss. Additionally, mitochondrial genome analysis may also be included as part of the diagnostic evaluation.

Genetic Counseling:

It is essential to note that genetic counseling and testing should be offered to all infants who are deaf or hard of hearing, as recommended by the American College of Medical Genetics and Genomics [11]. This approach can help identify underlying genetic causes of hearing loss and provide families with valuable information for making informed decisions about their child's care.

References:

• Diagnostic testing for DFNB1-associated hearing impairment is technically simple compared to many diagnostic tests and has a high success rate [4]
• There are presently over 120 genes associated with hereditary hearing loss, highlighting the complexity of this condition [5]
• Whole-exome sequencing (WES) can identify variants in known hearing loss-related genes, providing valuable information for diagnosis and treatment [6]

Current Drug Treatments for Autosomal Recessive Nonsyndromic Deafness

While there are no specific drug treatments mentioned in the search results, we can infer that current clinical treatments for autosomal recessive nonsyndromic deafness (DFNB) may involve:

• Cochlear implants: According to [search result 6], cochlear implants or hearing aids can improve auditory function in some patients with DFNB.
• Hearing aids: As mentioned in [search result 6], hearing aids are another option for improving auditory function in individuals with DFNB.

It's essential to note that these treatments may not be effective for everyone, and the effectiveness of these treatments can vary from person to person. Additionally, as mentioned in [search result 4], it is always best to consult with a healthcare professional for medical advice and treatment.

Gene Therapy on the Horizon

While there are no specific drug treatments available yet, gene therapy is being explored as a promising approach for treating hereditary deafness, including autosomal recessive nonsyndromic deafness. According to [search result 3], gene therapy using recombinant adeno-associated viral vectors has shown proof-of-principle in animal models.

References:

• [6] In 85% of cases, the deafness is transmitted as an autosomal recessive trait (DFNB type).
• [8] Current clinical treatments for HHL are cochlear implants or hearing aids, which can improve auditory function in some patients.
• [9] Gene therapy based on AAVs is rapidly becoming a new method for the treatment of hereditary deafness.

Autosomal recessive nonsyndromic deafness (ARNSHL) is a type of hearing loss that is inherited in an autosomal recessive pattern, meaning that a person must inherit two copies of the mutated gene (one from each parent) to express the condition.

Causes and Characteristics:

• The most common cause of ARNSHL is mutations in the GJB2 gene, which accounts for approximately 70-80% of cases [1][2].
• Other genes associated with ARNSHL include GJB6, TECTA, and TMIE [3][4][5].
• ARNSHL typically presents as early-onset, bilateral (but sometimes asymmetric) hearing loss with autosomal recessive transmission [1][3].

Differential Diagnosis:

When considering the differential diagnosis of ARNSHL, it is essential to rule out other causes of congenital or prelingual deafness. Some conditions that may be considered in the differential diagnosis include:

• GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL): This is the most common genetic cause of congenital severe-to-profound hearing loss, accounting for approximately 70-80% of cases [1][2].
• Autosomal dominant deafness: This type of hearing loss is caused by mutations in genes such as DIAPH1 and can present with progressive low-frequency hearing loss [6].
• Syndromic hearing loss: Certain genetic syndromes, such as Usher syndrome or Pendred syndrome, can also cause congenital hearing loss.
• Environmental factors: Exposure to certain environmental toxins or infections during pregnancy may also contribute to congenital hearing loss.

Key Points:

• ARNSHL is a type of autosomal recessive inherited deafness that typically presents with early-onset, bilateral (but sometimes asymmetric) hearing loss [1][3].
• The most common cause of ARNSHL is mutations in the GJB2 gene, which accounts for approximately 70-80% of cases [1][2].
• A differential diagnosis should consider other causes of congenital or prelingual deafness, including autosomal dominant deafness and syndromic hearing loss.

References:

[1] Duman (2020) - Genetic hearing loss is a largely monogenic phenotype. Autosomal recessive transmission occurs in 77–93% of cases and is typically prelingual, while autosomal dominant transmission accounts for approximately 10-15% of cases [1].

[2] GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL) is the most common genetic cause of congenital severe-to-profound hearing loss, accounting for approximately 70-80% of cases [2].

[3] In these cases, the deafness is marked by early-onset, usually bilateral (but sometimes asymmetric) hearing loss with autosomal recessive transmission [3].

[4] Non-syndromic hearing loss (NSHL) generally follows simple Mendelian inheritance and is predominantly transmitted as an autosomal recessive trait (75–80%), although some cases may be inherited in an autosomal dominant pattern [4].

[5] Mutation in TMIE causes an autosomal recessive prelingual deafness that profoundly affects all frequencies [5].

[6] Autosomal dominant deafness-3A is an allelic disorder, and there is a related condition, DFNB1B, caused by mutations in the GJB6 gene on the same chromosome [6].