Genetics Flashcards
(39 cards)
What are the three different stages of the gestational period?
- preembryonic (fertilization to 3 weeks)
- embryonic (4-8 weeks)
- fetal (9 weeks to birth)
What are the three germ cells or layers of tissues developed in the pre-embryonic stage?
- ectoderm
- mesoderm
- endoderm
which leads to the development of organs and tissues of the fetus
Which germ cell or layer of tissues is relevant for the auditory and vestibular system? Why is it relevant?
ectoderm (outer layer)
It gives rise to the inner, sensory epithelia, epidermis, and central nervous system.
What germ cell or layer of tissue are the Eustachian tube and middle ewar cavity from?
Endoderm
Which days do the neural tube, brain, and spinal cord begin to develop?
Days 14- 17 post-fertilization
What week of gestation gives rise to the CNS?
The fourth week
What week does the cochlear turn develop?
Week 16 (embryonic stage)
The membranous and bony labyrinths become fully developed by week ___. This marks what?
Week 20
Marks anatomic and mechanical structure is in place, but neuroelectrical system and outer hearing mechanisms are not yet primed to establish functional hearing.
Cochlear bony and membranous structures are at full size by ______. Which develops what?
Week 34
Develops base to apex (which develops HF first)
Achondroplasia
Autosomal dominant
Identifiers:
* Form of short-limbed dwarfism
* Enlarged heart
* Depressed nasal bridge
* Short, stubby hands
* Lordotic lumber spine
* Protruding abdomen
Auditory Findings:
Ear infections
CHL or SNHL
Alport syndrome
Apert Syndrome
**Autosomal dominant **
Fused fingers and toes
Possible stensois or atresia
Bilateral flat CHL, can be SNHL
AUNA1
Autosomal dominant
Nonsyndromic
ANSD with late teen onset
Progress to profound
CHARGE
Autosomal dominant
-Ocular abnormality (coloboma)
-Heart defects
-Abnormal nasal structure (atresia chonae)
-Delayed growth and pubery
-Genital abnormalities
SNHL and MHL mild to profound HL
balance problems
Colomba of the eye, heart defects, atresia of the nasal choanae, growth retardation, genital abnormalities
Congential unilateral lower lip palsy (CULLP)
Autosomal dominant
Asls due to birth trauma (compression of nerve)
-Unilateral facial paralysis seen when baby cries
-POSSIBLE SNHL
Connexin 26
Autosomal dominant; can be autosomal recessive
Nonsyndromic
Progressive bilateral SNHL
Jervell & Lange-Nielsen
Autosomal recessive
Prolonged heart QT
Repeated syncope attacks
Seizures
Bilateral profound SNHL
Noonan syndrome
Autosomal dominant
-Short stature
-Widely spaced eyes (usually blue or green)
-High-arched palate
-Downward palpebral fissure
-Short nose
-Broad or webbed neck
-Hypotonia
-Cardiac anomalies
-Middle and inner ear anomlies
-CHL, MHL, SNHL
Stickler syndrome
Autosomal dominant
-Flat facial profile
-Mandibular hypoplasia
-Cleft palate
-Musculoskeletal and joint issues
-Joint hypermobility
-Osteoarthritis
-Long limbs
-Slender bones
-Nearsighted
-Retinal detachment
-Cataracts
-Blindness
Auditory findings:
-Type 1- HF SNHL
-Type 2- severe and progressive SNHL
-Type 3- mild to moderate SNHL
Pendred syndrome
Autosomal recessive
Goiter (enlarged thyroid)
-Bilateral HF SNHL, progressive
-Enlarged vestibular aqueduct
-Possible vestibular anomalies
Treacher Collins
Autosomal dominant or recessive
Craniofacial abnormalities
Pinna deformities
Primarily CHL, can be MHL or SNHL
Usher Syndrome with ages
Type 1- age 10
Type II- early 20s
Type II- puberty
Autosomal recessive
Retinitis pigmentosa (progressive eye disease)
Auditory:
-Bilateral SNHL (progressive- Type i & III
-Dizziness and/or imbalance
Waardenburg syndrome
Autosomal dominant (Type I & II)
Autosomal recessive (Type III & IV)
-White forelock
-Upper limb anomalies (Type III)
-Hirschprung disease (Type IV)
-Dystopia canthorum (wide nasal bridge)
-Heterohromia (Type III)
-Musculoskeletal (Type III)
The external ears (pinna) migrate to the final newborn position when?
Week 9-16
