What type of HL can you expect from a MT-RNR1 mutation?

late onset moderate-profound sensorineural HL

What is the function of MT-RNR1?

to encode mitochondrial RNA proteins

Is MT-RNR1 homoplasmic or heteroplasmic?

homoplasmic

What is the function of MT-TS1?

it encodes mitochondrial transfer RNA for serine

Is MT-TS1 homoplasmic or heteroplasmic?

What type of hearing loss is associated with a MT-TS1 mutation?

childhood onset of sensorineural hearing loss

Nonsyndromic mitochondrial hearing loss and deafness is transmitted by what type of inheritance?

it is transmitted by maternal inheritance

How are the offsprings affected if a female has an mtDNA mutation? If the male has the mutation?

What is Treacher Collins syndrome caused by?

it is caused by a defective protein called treacle

What is the function of the Treacle protein?

treacle is a critical protein for development of bones in the face that come from the cephalic neural crest

What is the prevalence of Treacher Collins syndrome?

~1/50,000 live births

What are the characteristic symptoms of Treacher Collins syndrome?

bilateral, symmetrical facial abnormalities (auricular tags, cleft palate, poor development of orbital bones, abnormal development of zygomatic arches, underdeveloped jaw), normal intelligence and cognition, inheritance pattern, ear abnormalities (low set abnormally small pinna)

What kind of hearing loss is associated with Treacher Collins?

mild to severe conductive hearing loss, not progressive

What causes Charge syndrome?

Describe the inheritance pattern for someone with Charge syndrome?

it is a spontaneous dominant mutation

What are the characteristic symptoms of Charge syndrome?

nasal airway blockage, coloboma, congenital heart disease, brain structure abnormalities, abnormally low intelligence and cognitive function, endocrine issues, potential renal issues, potential skeletal issues, facial nerve palsy

small, absent lobes, ossicular anomalies, middle ear structure anomalies

What is the prevalence of charge syndrome?

~1/8,500-10,000 live births

What is the prevalence of Jervell & Lange-Nielsen?

1/170,000-625,000

Describe the pattern on inheritance for Jervell & Lange-Nielsen

recessive

What are the symptoms of Jervell & Lange-Nielsen?

cardiac abnormalities (seizures, cardiac arrest, sudden death, fainting)

What is the hearing loss associated with Jervell & Lange-Nielsen?

congenital, profound, bilateral SNHL

What causes Pendred syndrome?

mutation on chromosome 7

What are the characteristic symptoms of Pendred syndrome?

goiter

What kind of hearing loss is associated with Pendred syndrome?

severe to profound congenital SNHL

Is Pendred syndrome progressive?

not progressive

What causes stickler syndrome?

mutations in collagen genes (chromosome 1 and/ 12)

What is the prevalence of stickler syndrome?

1:7,500-1:9,000

What are the characteristic symptoms of stickler syndrome?

cleft palate, joint abnormalities, eye abnormalities, midface flattening

What hearing loss is associated with Stickler syndrome?

high frequency sensorineural hearing loss, progressive (60-90%)
mixed hearing loss (30%)

What causes Waardenburg Syndrome?

mutation on chromosome 2; PAX3 mutation or deletion

What is the prevalence of Waardenburg Syndrome?

1/10,000-1/20,000

What are the characteristic symptoms of Waardenburg syndrome?

white forelock, premature graying, eye pigment disturbance, wide set eyes, broad nasal root

What type of hearing loss do you get when you have Waardenburg syndrome?

congenital, moderate-profound SNHL, typically bilateral

What is the inheritance pattern of Waardenburg syndrome?

autosomal dominant

What are the characteristic symptoms of Usher syndrome?

deafness, blindness, vestibular involvement

What is the prevalence of Usher syndrome?

3.6-6.2/100,000

What is the inheritance pattern for Usher syndrome?

autosomal recessive

Describe Type 1 Usher syndrome

characteristic symptoms: blindness, onset in childhood, absence of vestibular responses, congenital, bilateral profound SNHL

Describe Type 2 Usher syndrome

characteristic symptoms: visual impairment, normal vestibular function, congenital, bilateral SNHL

Describe Type 3 Usher syndrome

characteristic symptoms: visual impairment, vestibular issues progressive in nautre, post-lingual, bilateral SNHL

What is the prevalence of down syndrome?

~1/740 live births

What is the inheritance pattern of down syndrome?

men are infertile, women have 50% chance of having offspring with down syndrome

What are the physical symptoms of down syndrome?

hypotonia at birth, flattened nose, single crease in the palm of the hand, small ears, small mouth, upward slanting eyes, wide short hands with short fingers, short stature, delayed physical development, heart defects, GI tract issues

What are the mental symptoms of down syndrome?

impulsive behavior, poor judgement, short attention span, slow learning, low IQ

What is the prevalence of Turner syndrome?

1/2000-2500 female births

What is Turner syndrome caused by?

caused by only one X chromosome

What is characteristic of NF type 2?

growth of bilateral vestibular schwannomas

What is the inheritance pattern for NF type 2?

autosomal dominant