Hearing Loss Flashcards
What is the phenotype of Usher syndrome?
Hearing loss
Retinitis pigmentosa (makes cells in the retina break down slowly over time, causing vision loss)
How many newborns are born profoundly deaf
1 in 1,000
What percentage of children in the US have low or high-frequency hearing loss?
15%
What genes cause Usher syndrome?
USH2A, MYO7A (AR)
What percentage of hearing loss is due to preventable causes and what are those causes?
Viruses, prematurity and perinatal complications, head injury, ototoxicity, noise)
CMV is the most common viral cause
What ratio of genetic causes of hearing loss is syndromic/non-syndromic?
1/3 syndromic
2/3 non-syndromic (50% caused by Connexin mutations)
What are the characteristics that you measure in hearing loss?
Conductive vs sensorineural
Unilateral vs bilateral
Pattern-rising, sloping, flat
Congenital (65%) or acquired (35%)
Severity
What does the pattern of conductive hearing loss look like charted?
Two horizontal parallel lines
(Fluid in the ear, ear wax, external abnormality)
What does the pattern of sensorineural hearing loss look like charted?
Two lines together descending
(Damage to the inner ear)
What does the pattern of conductive and sensorineural hearing loss together look like charted?
Two parallel lines descending
What is diagnostic testing you would perform in Jervell-Lange-Nielsen syndrome (profound hearing loss at birth)?
EKG
Long QT syndrome, which is a heart condition that causes the heart (cardiac) muscle to take longer than usual to recharge between beats.
What is the phenotype of Alport syndrome?
Hearing loss
Kidney disease (blood in urine)–Urinalysis
Eye abnormalities that seldom lead to vision loss
What is the gene that causes Alport syndrome?
COL4A5 (X-linked)
What is the phenotype of Branchio-oto-renal syndrome?
Branchial cleft cysts in the neck
Hearing loss
Ear abnormalities
Ear pits/tags
Renal abnormalities–Renal ultrasound
What is the gene that causes Branchio-oto-renal syndrome?
EYA1 (AD)
What is the phenotype of Non-syndromic hearing loss and deafness (DFNB1)?
Congenital, non-progressive, mild to profound sensorineural hearing loss
What genes cause Non-syndromic hearing loss and deafness (DFNB1)?
GJB2 and GJB6 (AR)
What is the phenotype in Pendred syndrome?
Enlarged vestibular aqueduct–characteristic (MRI)
Severe to profound sensorineural hearing loss
Balance issues
Goiter (enlarged thyroid gland)
What is the phenotype of Treacher Collins syndrome?
Affects facial bones and tissue
Underdeveloped facial bones, micrognathia
Hearing loss in 50%
What gene causes Treacher Collins syndrome?
TCOF (AD)
What is the phenotype of Waardenburg sydnrome?
Heterochromia
Patch of white hair on head
Moderate to profound congenital hearing loss although most have normal hearing
How does the cochlear implant work?
Transmits sound directly to the auditory nerve through electrical stimulation of the cochlea
What is the earliest you can implant a cochlear implant?
9 months
Hearing aid trial for minimum of 3-6 mos
