Y-linked deafness 2

Characteristics of Y-linked Deafness-2 (DFNY2)

Y-linked Deafness-2, also known as DFNY2, is a rare genetic disorder that affects only males. The primary symptom of this condition is male-limited bilateral progressive sensorineural hearing loss, which means that both ears are affected and the hearing loss progresses over time.

• The onset of hearing loss can vary, but it typically starts in the third decade of life (around age 20-30).
• The severity of hearing loss can range from mild to severe.
• This condition is characterized by a male-limited inheritance pattern, meaning that only males are affected and females are not.

Other possible symptoms

While hearing loss is the primary symptom of DFNY2, some individuals may also experience other related issues. These can include:

• Facial abnormalities: Some people with DFNY2 may have distinctive facial features.
• Unusually diminished coloration: There may be changes in skin, hair, and iris pigmentation.

Important note

It's essential to consult a medical professional for an accurate diagnosis and proper guidance. They can assess individual symptoms and provide personalized advice on next steps.

References:

[2] Y-linked deafness-2 (DFNY2) is characterized by male-limited bilateral progressive sensorineural hearing loss of variable severity, with onset in the third ... [6] A single Mendelian trait has been mapped to the human Y chromosome: Y-linked hearing impairment. The molecular basis of this disorder is unknown.

Diagnostic Tests for Y-linked Deafness 2

Y-linked deafness 2 (DFNY2) is a form of non-syndromic sensorineural hearing loss that affects males, characterized by bilateral progressive hearing loss of varying severity, typically starting in the third to fifth decades of life. The condition is caused by mutations in the TBL1Y gene located on chromosome Yp11.2.

Genetic Testing

Genetic testing for DFNY2 involves analyzing the DNA sequence of the TBL1Y gene to identify any mutations that may be causing the hearing loss. This can be done through various methods, including:

• Sequence analysis: This involves sequencing the entire coding region of the TBL1Y gene to look for any changes in the DNA sequence.
• Next-Generation (NGS)/Massively parallel sequencing (MPS): This is a more comprehensive approach that allows for the simultaneous analysis of multiple genes, including the TBL1Y gene.

Clinical Molecular Genetics Test

A clinical molecular genetics test for DFNY2 is available through CEN4GEN Institute for Genomics and Molecular Diagnostics. This test uses sequence analysis of the entire coding region, NGS/MPS to identify any mutations in the TBL1Y gene that may be causing the hearing loss.

Other Diagnostic Tests

While genetic testing is a key diagnostic tool for DFNY2, other tests such as:

• Whisper test: A simple test where words are spoken at various volumes while covering one ear at a time to assess hearing ability.
• Comprehensive audiological evaluation: A thorough assessment of hearing function that includes pure-tone audiometry and speech audiometry.

may also be used in conjunction with genetic testing to confirm the diagnosis of DFNY2.

References

[10] Y-linked deafness-2 (DFNY2) is characterized by male-limited bilateral progressive sensorineural hearing loss of variable severity, with onset in the third to fifth decades of life (Di Stazio et al., 2019). For a discussion of genetic heterogeneity of Y-linked deafness, see DFNY1 (400043).

[13] Y-linked deafness-2 (DFNY2) is a form of non-syndromic sensorineural hearing loss that affects males. It is characterized by bilateral progressive hearing loss of varying severity, typically starting in the third to fifth decades of life.

[12] Clinical Molecular Genetics test for Deafness, Y

Current Status of Drug Treatment for Y-linked Deafness 2

Unfortunately, there are currently no FDA-approved drugs to treat Y-linked deafness 2 (DFNY2), a form of inherited hearing loss. However, researchers are exploring various approaches to develop effective treatments.

• Gene therapy: Gene therapy is being investigated as a potential treatment option for DFNY2. This approach involves introducing healthy copies of the affected gene into the inner ear to restore hearing function [9].
• Novel gene therapies: Recent studies have shown promising results with novel gene therapies designed to target inherited deafness, including Y-linked deafness 2 [7], [10]. These approaches aim to overcome challenges presented by large genes and restore hearing function in affected individuals.
• Research and development: Researchers are actively working on developing new treatments for DFNY2. However, more research is needed to fully understand the underlying mechanisms of this condition and to identify effective therapeutic strategies.

Key Points

• No FDA-approved drugs exist for Y-linked deafness 2 (DFNY2)
• Gene therapy and novel gene therapies are being explored as potential treatment options
• Research is ongoing to develop new treatments for DFNY2

Citations:

[7] Jan 24, 2024 — A novel gene therapy approach has given five children who were born deaf the ability to hear. The method, which overcomes a roadblock presented by large genes, [9] Y-linked deafness-2 (DFNY2) is characterized by male-limited bilateral progressive sensorineural hearing loss of variable severity, with onset in the third ... [10] Jun 5, 2024 — A novel gene therapy designed to target a form of inherited deafness restored hearing function in five children who were treated in both ears.

Differential Diagnosis of Y-linked Deafness, Type 1

Y-linked deafness, type 1 is a rare form of hereditary non-syndromic deafness that affects only males. The differential diagnosis for this condition involves ruling out other possible causes of hearing loss in males.

• Genetic testing: Genetic testing can confirm the presence of Y-linked deafness, type 1 by identifying mutations in the specific gene responsible for this condition [3].
• Other genetic causes of hearing loss: Other genetic conditions that cause hearing loss should be ruled out, such as those caused by mutations in other genes on the Y chromosome or autosomal chromosomes [6][7].
• Environmental and acquired causes of hearing loss: Environmental and acquired factors that can cause hearing loss, such as exposure to loud noises, infections, or head trauma, should also be considered [8].

Key Points

• Y-linked deafness, type 1 is a rare form of hereditary non-syndromic deafness that affects only males.
• Genetic testing can confirm the presence of this condition.
• Other genetic and environmental causes of hearing loss should be ruled out in the differential diagnosis.

References:

[3] Wang Q. A single Mendelian trait has been mapped to the human Y chromosome: Y-linked hearing impairment. [2013]

[6] Martini A. Overall, genetic factors account for at least 40% of the cases, and a relevant portion of affected patients can have a definite molecular diagnosis thanks to ... [2021]

[7] Zhong LX. 50% of profound HL can be attributed to genetic causes. With over 60 genes implicated in nonsyndromic hearing loss, it is also an extremely heterogeneous trait. [2013]

[8] Martini A. Once confirmed, the differential diagnosis includes all genetic and environmental causes of hearing loss. Conductive hearing loss must be differentiated ... [2024]