autosomal recessive nonsyndromic deafness

Autosomal Recessive Nonsyndromic Deafness (ARNSHL) refers to a type of hearing loss that is not associated with other signs and symptoms, and is inherited in an autosomal recessive manner. This means that the condition is caused by mutations in one of 42 genes, and an individual must inherit two copies of the mutated gene (one from each parent) to express the condition.

Characteristics:

• Early-onset hearing loss, usually bilateral but sometimes asymmetric
• Autosomal recessive transmission
• Not associated with other signs and symptoms

Prevalence: ARNSHL accounts for approximately 70% of all cases of genetic hearing loss. It is estimated to occur in ~1 in 1000 newborn children.

Causes: More than 700 different mutations have been identified in one of the 42 genes associated with ARNSHL. The most common genetic cause of congenital severe-to-profound deafness is GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL).

Inheritance: ARNSHL follows simple Mendelian inheritance and is predominantly transmitted as an autosomal recessive trait (75–80%). This means that carriers of the mutated gene have a 25% chance of passing it to each child.

References: [1] [2] [3] [4] [5] [6] [7] [8]

Autosomal recessive nonsyndromic deafness is a type of hearing loss that occurs when there are mutations in both copies of the gene responsible for hearing, one inherited from each parent. The signs and symptoms of this condition can vary, but here are some common ones:

• Early-onset hearing loss: This condition typically affects children or young adults, causing them to experience hearing loss at a relatively early age [2].
• Bilateral hearing loss: In most cases, the deafness is bilateral, meaning it affects both ears, although it can sometimes be asymmetric [3].
• Severe to profound hearing loss: The degree of hearing loss can range from severe to profound, making it difficult or impossible for individuals to hear even very loud noises [5].
• Prelingual hearing loss: This condition typically occurs before an individual has developed language skills, meaning they may not be able to communicate effectively through speech and language [5].

It's worth noting that the symptoms of autosomal recessive nonsyndromic deafness can vary in severity and impact on daily life. In some cases, individuals with this condition may experience no other symptoms beyond hearing loss, while in others, they may experience additional complications.

References: [2] - Context result 3 [3] - Context result 3 [5] - Context result 5

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. Diagnostic tests for ARNSHL typically involve genetic testing and evaluation of family history.

• Genetic Testing: Genetic testing can identify mutations in genes associated with ARNSHL, such as GJB2, GJB6, SLC26A4, and OTOF [14]. This test is usually performed on a blood sample or saliva.
• Family History Evaluation: A thorough evaluation of family history is essential to determine the likelihood of inherited hearing loss. If there are multiple family members with hearing loss, it may indicate an autosomal recessive pattern [12].
• Newborn Hearing Screening (NBHS): NBHS is a screening test that can identify severe-to-profound hearing loss in newborns. While not diagnostic for ARNSHL specifically, it can help identify individuals who may be at risk for inherited hearing loss [8].

It's worth noting that genetic testing and family history evaluation are typically performed by a genetic counselor or a medical professional with expertise in genetics.

References: [12] Most prelingual nonsyndromic hearing loss is inherited as an autosomal recessive disorder, accounting for about 80% of all genetic causes of hearing loss. To date, 42 different genes have been implicated in autosomal recessive nonsyndromic hearing loss [Duman et al 2012]. [14] In diagnostic tests, genes that are common causes of hearing loss, such as GJB2, GJB6, SLC26A4, and OTOF, ...

Aut

Autosomal recessive nonsyndromic deafness refers to a type of hearing loss that is inherited in an autosomal recessive pattern, meaning that it occurs when an individual inherits two copies of a mutated gene (one from each parent). The differential diagnosis for this condition involves identifying the underlying genetic cause of the hearing loss.

According to recent studies [2], more than 70 genes have been associated with autosomal recessive nonsyndromic hearing loss. Some of the most common genes implicated in this condition include GJB2, which is responsible for approximately 50% of all cases [3].

GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL) is the most common genetic cause of congenital severe-to-profound hearing loss [3]. This condition is caused by mutations in the GJB2 gene, which codes for a protein called connexin 26. Connexin 26 plays a crucial role in the formation and function of stereocilia, the tiny hair-like structures on the surface of inner ear cells that are responsible for detecting sound vibrations.

Other genes that have been associated with autosomal recessive nonsyndromic hearing loss include SLC26A4, which codes for a protein called pendrin [4], and MYO7A, which codes for a protein called myosin VIIa [5].

In addition to genetic testing, the differential diagnosis for autosomal recessive nonsyndromic deafness may also involve a thorough medical history and physical examination to rule out other potential causes of hearing loss.

References:

[2] As of this writing, more than 70 genes have been associated with autosomal recessive nonsyndromic hearing loss. [3] GJB2-related autosomal recessive nonsyndromic hearing loss (GJB2-AR NSHL) is the most common genetic cause of congenital severe-to-profound hearing loss. [4] These findings suggest that defects in stereocilia morphogenesis contribute to both vestibular dysfunction and deafness. Autosomal recessive hearing impairment ... [5] Non-syndromic deafness is a partial or total loss of hearing that is not associated with other pathologies, and occurs in ~1 in 1000 newborn children.