Genetic Causes of Hearing Loss
Syndromic (More than one organ system involvement)= 30% of deaf children
Waardenburg Syndrome
Stickler Syndrome
Branchio-oto-renal Syndrome
Treacher Collins Syndrome
Neurofibromatosis
Otosclerosis
Osteogenesis Imperfecta
Usher Syndrome
Pendred Syndrome
Jervell and Lange-Neilsen Syndrome
Norrie Syndrome
Otopalatodigital Syndrome Type I and Type II
Wildervaank Syndrome
Alport Syndrome
Multifactorial Genetic Disorders
  • clefting syndromes, involving conductive hearing loss
  • microtia/hemifacial microsomia/Goldenhar spectrum.
  • Goldenhar’s syndrome ( preauricular tags/pits, vertebral anomalies such as hypoplastic or hemivertebrae in the cervical region, epibulbar dermoids, and coloboma of the upper lid.
  • multifactorial inheritance of susceptibility to hearing loss and hyperlipidemia.
  • Chromosomal Syndromes
  • Down syndrome children (Middle ear, mastoid disease, and sensorineural hearing loss)
  • Trisomy 13 (sensorineural hearing loss in survivors)
  • Turner’s syndrome, monosomic for all or part of one X chromosome (gonadal dysgenesis, short stature, and often webbed neck or shield chest, sensorineural, conductive, or mixed hearing loss, which can be progressive and may be the first evidence of the syndrome in prepubertal females.)
  • Mitochondrial Disorders
    • Keams-Sayre
    • MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke)
    • MERRF (myoclonic epilepsy with ragged red fibers)
    • Lebers hereditary optic neuropathy
    • A condition involving diabetes, hearing loss, and stroke due to a mitochondrial deletion.
    • Enhanced sensitivity to the ototoxic effects of aminoglycosides
    Non-Syndromic (Isolated Inner-ear/Cochlea-Vestibule defect)
    Dominant Progressive Hearing Loss (More than 12 genes have been localized.)
    • Early onset
    • High Frequency
      • Type I
      • Type II
      • Type III
      • Type IV
    • Mid Frequency
    • Low Frequency
    Recessive Nonsyndromic Hearing Loss (15 gene loci including: the most common DFNB2/connexin 23 on chromosome 13 and DFNB1/connexin 26 , also found on chromosome 13 )
    • Congenital severe-profound (most prevalent
    • Congential moderate
    • Early Onset (progresses rapidly from onset at age 1 ½ years to profound loss by age 6 )
    Nonsyndromic X-Linked Hearing Loss ( at least 6 loci : Xp21.2, Xq13-q21.2, DNF3/POU3F4
    • Early onset rapidly progressive
    • Moderate slowly progressive