From the Guidelines
Hearing loss associated with a syndrome typically refers to sensorineural hearing impairment that occurs as part of a recognized medical condition or syndrome, such as Usher syndrome, Waardenburg syndrome, or Pendred syndrome, which can affect multiple body systems beyond hearing loss. This type of hearing loss is often congenital or develops early in life due to genetic disorders. According to the most recent study 1, approximately 30% of congenital hearing loss cases are associated with genetic syndromes, while 70% are nonsyndromic. The hearing impairment in syndromic cases may be conductive, sensorineural, or mixed, and management requires a multidisciplinary approach addressing both the hearing loss and other syndrome manifestations.
Key aspects of syndromic hearing loss include:
- Age of onset: congenital, prelingual, or postlingual
- Type of hearing loss: sensorineural, conductive, mixed, or auditory neuropathy
- Laterality and symmetry: unilateral or bilateral, symmetric or asymmetric
- Stability: progressive, nonprogressive, or fluctuating
- Degree of hearing loss: slight, mild, moderate, moderately severe, severe, or profound
Early identification through genetic testing and newborn hearing screening is crucial for timely intervention, as it allows for the implementation of personalized health maintenance strategies and appropriate referrals for therapeutic options. Understanding the genetic basis of syndromic hearing loss helps in predicting progression, planning interventions, and providing genetic counseling for affected families, as highlighted in 2. The most common syndromes associated with hearing loss include Down syndrome, Usher syndrome, Waardenburg syndrome, and Pendred syndrome, each with distinctive features beyond hearing loss, as noted in 3 and 4. However, the most recent and highest quality study 1 provides the most up-to-date information on the clinical evaluation and etiologic diagnosis of hearing loss.
From the Research
Types of Hearing Loss Associated with a Syndrome
- Usher syndrome is a syndromic form of genetic hearing loss that is accompanied by impaired vision associated with retinitis pigmentosa and, in many cases, vestibular dysfunction 5
- Down syndrome is associated with conductive hearing loss, but a small proportion of children with Down syndrome may have severe to profound sensorineural hearing loss that could benefit from cochlear implantation 6
- Usher syndrome type IIa is characterized by congenital moderate to severe hearing impairment and retinitis pigmentosa, and cochlear implantation can increase performance and quality of life in patients with this condition 7
- Type 2 Usher Syndrome is a cause of sensorineural hearing loss, and early detection of this condition with audiological and ophthalmic examination can improve the quality of life, improve hearing, and delay the progression of complete blindness 8
Characteristics of Hearing Loss in Usher Syndrome
- Usher syndrome is the most common cause of deaf-blindness, and it is divided clinically into three significant groups: Type I, Type 2, and Type 3 5, 8
- Individuals with Usher syndrome type 1 have congenital, profound hearing loss, and recent research in genetics indicates that the cause of deafness in individuals with Usher type 1 could be beneficial for the outcome with cochlear implants 9
- Children with Usher syndrome type 1 and cochlear implants have a similar level of performance on cognitive tasks as children with hearing impairment and hearing aids, but have a different performance profile on tests of working memory, phonological skill, and lexical skill than children with non-Usher syndrome deafness using cochlear implants 9