DFNB48 is an autosomal recessive form of deafness. Affected individuals have prelingual onset of severe to profound sensorineural hearing loss affecting all frequencies (summary by Riazuddin et al., 2012).

Autosomal recessive deafness-3 (DFNB3) is a congenital, profound, neurosensory deafness. There are no apparent vestibular abnormalities or dysmorphic features (Friedman et al., 1995).

Congenital deafness with labyrinthine aplasia, microtia, and microdontia (LAMM syndrome) is characterized by: profound bilateral congenital sensorineural deafness associated with inner ear anomalies (most often bilateral complete labyrinthine aplasia); microtia (type I) that is typically bilateral (although unilateral microtia and normal external ears are observed on occasion); and microdontia (small teeth). Individuals with LAMM syndrome commonly have motor delays during infancy presumably due to impaired balance from inner ear (vestibular) abnormalities. Growth, physical development, and cognition are normal.

An autosomal recessive nonsyndromic deafness that has material basis in variation in the chromosome region 18p11.32-p11.31.

Any autosomal recessive nonsyndromic deafness in which the cause of the disease is a mutation in the RDX gene.

Autosomal dominant deafness-78 (DFNA78) is characterized by profound congenital bilateral sensorineural hearing loss affecting all frequencies. Some patients may have mild motor delay early in life due to vestibular dysfunction, although the motor skills catch up with age. Affected individuals do not have systemic or other neurologic manifestations (summary by Mutai et al., 2020).

Congenital deafness and adult-onset progressive leukoencephalopathy (DEAPLE) is an autosomal recessive complex neurodegenerative disorder characterized by congenital neurosensory deafness followed by onset of neurodegenerative symptoms, including pyramidal signs and cognitive decline, in young adulthood. Some patients may have mild developmental delay or learning difficulties in childhood, but most can function independently. The onset of motor and cognitive decline in adulthood can be rapid and may result in early death. Brain imaging shows diffuse white matter abnormalities affecting various brain regions, consistent with a progressive leukoencephalopathy. More variable additional features may include visual impairment and axonal peripheral neuropathy (summary by Scheidecker et al., 2019).

Congenital cranial dysinnervation disorder with absent corneal reflex and developmental delay (CCDDRD) is an autosomal recessive disorder characterized by abnormal development of the proximal cranial sensory ganglia and nerves, mainly CN V (trigeminal nerve) and CN VIII (vestibulocochlear nerve). Affected individuals present at birth or in early infancy with corneal opacities due to absent blinking. Most patients also have sensorineural deafness associated with hypoplastic or malformed cochlea and hypoplasia or agenesis of CN VIII. Developmental delay with poor speech and autistic behavior are also present. Additional features may include expressionless face, feeding or chewing difficulties due to oromotor dysfunction, and dysmorphic facial features (Dupont et al., 2021; Sheth et al., 2023).