syndromic hearing disorders Flashcards
syndromic condition categories
- External ear changes
- Eye abnormalities
- Renal
- Cardiac
- Endocrine
- musculoskeletal
- Neurological
- Metabolic
- Integumentary
23 total disorders
syndromic conditions associated with external ear changes
- treacher collins
- branchio-oto-renal (BOR)
- oculo-auriculo-vertebral (OAV)
- CHARGE syndrome
treacher collins syndrome
autosomal dominant (AD) 1st and 2nd brachial arch syndrome caused by deletions or nonsense mutations of the gene that codes treacle protein
- Treacle is a protein plays a crucial role in the development of face structures derived from brachial arch 1 & 2
majority of
treacher collins syndrome characteristics
- receding chin
- tears in eye structure
- large fish-like mouth
audiologic findings in treacher collins
malformed pinna, atresia (no ear canal), absent or malformed ossicles, absence of ME cavity, mild to moderate conductive HL
treatment approach for treacher collins
cleft palate repair, BAHA, speech therapy and educational intervention
treacher collins differential diagnosis
oculo-auriculo-vertebral syndrome (OAV)
branchio-oto-renal (BOR) syndrome
AD inheritance of HL with a transcription factor that is involved within the inner ear and kidney cell development
- cysts on kidneys and facial anomalies
audiologic findings of BOR
- conductive, SNHL, or mixed HL (most common)
- branchial cysts/fistulas
- malformation of pinna
- EAC stenosis (complete closure)
- ossicular deformities
BOR vs Alports
BOR: cystic kidneys
Alports: inflammation of kidneys
oculo-auriculo-vertebral (OAV)
complex of 3 rare congenital disorders resulting in unilateral malformation of craniofacial structures from the 1st and 2nd arches with multifactorial inheritance
- the mildest of the combined 3 complex disorders
what are the 3 complex rare genetic conditions that are believed to be related to one another?
- Goldenhaar (most severe form)
- Hemifacial Microsomia (intermediate form)
- OAV (mildest form)
OAV characteristics
asymmetrical facial abnormalities, cardiac anomalies, vertebral anomalies and deafness or blindness
OAV audiological findings
pinna anomalies:
- tags, microtia, EAC stenosis
conductive HL
SNHL (rare)
CHARGE association syndrome
most cases are sporadic however could be AD
C: coloboma (tear in eye structure)
H: heart defects
A: atresia (narrowing) of nasal conchae
R: Retardation (delay) of growth & development
G: Genital abnormalities & underdeveloped sexual organs (infertile)
E: Ear abnormalities & deafness:
audiologic findings of CHARGE
- external ear anomalies
- ossicular malformations with ET dysfunction - mondini (incomplete cochlea), considered to be a deaf/blind syndrome
syndromic conditions associated with eye disease
usher syndrome and norrie syndrome
usher syndrome
affects the ears and eyes with 3 types and is the most common AR syndromic HL
-most mutations lead to the loss of hair cells in the inner ear and gradual loss of rods and cones within the retina (retinitis pigmentosa)
type 1 usher’s
congenital severe to profound SNHL
- traditional amplification is ineffective
- abnormal vestibular and gait ataxia
- delayed motor milestones
type 2 usher’s
milder than type 1
- congenital mild to severe SNHL
- hearing aids are effective
- normal vestibular function
type 3 usher’s
RARE
- progressive SNHl w/ progressive vestibular dysfunction
- possible founder effect (small gene pool due to consanguinity)
usher syndrome differential diagnosis
norrie syndrome & other disorders with retinitis pigmentosa (RP) and SNHL
explain some other common syndrome’s that have retinitis pigmentosa (RP) & hearing loss
- hallgren syndrome: ataxia, pigmentary retinopathy and SNHL
- cockayne syndrome: associated with dwarfism and motor disturbances
- alstrum syndrome: associated diabetes mellitus
- refsum syndrome: triad of RP, peripheral neuropathy and ataxia SNHL (asymetrical)
norrie syndrome
eyes, hearing, cognitive, & psychological issues
- x-linked recessive
- male phenotype bc males only have one x so no balance
- if it comes from dad girls will be carriers
- mutation is believed to be a deletion
norrie syndrome characteristics
-onset within the 2nd decade
-retinal detachment, congenital progressive blindess NOT caused by RP, cataracts and CNS involvement
audiologic findings of norrie syndrome
progressive moderate to severe SNHL, flat or sloping, atrophy of stria vascularis with degenerations of hair cells
syndromic conditions associated with musculoskeletal diseases
crouzon, stickler, achondroplasia and osteogenesis imperfecta
crouzon syndrome
premature closure of cranial sutures with resulting contracted skill
-AD transmission with mutations in the protein that makes fibroblast growth factors which turns cells to bone
crouzon syndrome characteristics
- abnormal shape head
- bulging eyes/vision problems by shallow eye sockets
- increased space between the eyes
audiologic findings of crouzon
atresia of EAC, ossicular defomity, absent or narrow oval/round window, conductive HL is most common
sitckler syndrome
Autosomal dominant collagen disorder
- mutations involve premature stop codons (nonsense mutations)
- 3 types (type 3 has no myopia bc it’s caused by a gene not expressed in the eye)
sitckler syndrome characteristics
- distinctive facial apperance: flat face high arched palate
- eye abnormalities: severe myopia, cataracts & glaucoma (blindness rare)
- joint problems
audiologic findings of stickler syndrome
mixed or pregressive high frequency SNHL
achondroplasia
form of short limbed dwarfism
-AD inheritance in familial cases but can be sporadic
achondroplasia characterstics
average trunk with short arms and legs, frontal bossing, stubby hands, bowed legs, lordotic lumbar spine, decrease in reproductive fitness
genotype with achondroplasia
homozygosity: both parents affected, lethal for offspring (AA)
Aa: dwarfism
aa: normal