Genetic and Development disorders Flashcards
Genetic Defect types
- X-linked (dominant vs recessive)
- Y-linked
- Autosomal dominant
- Autosomal recessive
- Codominant: 2 differnet allels of a gene are expressed
- mitochondrial inhertied disease
Diagnosis of a genetic defect
- Chromosomal testing/DNA analysis
- Blood tests
- clinical exam
- EMG, Muscle biopsy
- often detected at birth
Causes of genetic defects
- mutations
- breakage of chromosomes
- transplant or chromosomes
Down syndrome: Etiology
- trisomy 21
- translocation of chromosome 15, 21, or 22
- mosaicism: fauly cell division occurs after fertilization (group of “normal” cells and group of mutated cells)
- can be related to mothers age
Down syndrome Diagnosis
- Triple screen: alpha fetoprotein, human chorionic gonadotropin, uncondjugated estrogen indicators to do more tests
- amniocentesis
Down syndrome
prognosis
- improved
- life expectancy is now 60+
Down syndrome
Clinical manifestations
- congenital heart disease (tetralogy of fallot)
- endocrine diseases
- Atlanto-axial instability
- alzheimers disease
- primitive reflexes persist
- sensory motor impairments
- affects muscule tone, increased joint laxity
- slower intiating movements
Down syndrome
Tetralogy of fallot
- hole between ventricles that doesnt close
- transposed Aorta over the hole
- pulmonary valve stenosis
- right ventricular hypertrophy
will have cynosis, decreased endurance
Down syndrome: AA joint laxity
- When you flex, extend, laterally rotate, and side bend there will be too much motion
- vertebral artery is in the are and the spinal nerves as well
- monitored to detect this and then will need to have is fused
- hypermobilty: careful with doing activites that will encourage a lot of movement at this joint
Scoliosis
What causes this/types
- iodapthic
- osteopathic: owning to spinal disease or bony abnormality
- myopathic: owing to muscule weakness
- neuropathic: owing to CNS disorders
Scoliosis
Age of onset classifcations
- infantile 0-3 years
- juvenile 3-10
- adolescent 10-bone maturity (18 -20)
- adult: after skeletal maturation
Measuring Scoliosis
- the top vertebra used in the measurement is identified as the uppermost vertebra whose upper surface tiltis toward the curvature concave side (superiro surface of the vertebra that is most tilted)
- the bottom vertebra is the lowest vertebra whose inferio surface tilts
- A line is drawn parallel to each of those vertbrae
- the angle formed by the two perpendicular lines drawn to each of these lines creates the angle curvature
Curves of scoliosis
medical conscern
- less than 25º= X-rays every so often to monitor
- 25-45º recommended to brace
- after 45º they ecommend surgery but depends on the activity level and the symptoms of the individual
- over 50º – beathing issues
- Risser measures skeletal maturity
Kyphoscoliosis
- Scheuermann disease (juvenile kyphosis, vertrbal epiphysitis)
- structural deformity classically characterzed by anterior wedging of 5ºor more of the three adjacent thoracic bodies
- affects adolescents 12-16 years old
- most common cause of structural kyphosis in adolescence
- likely autosomal dominant but etiological factors and pathogenesis of this excessive kyphosis are unknown
Normal neural tube development
- about 20 days after conception: neural groove develops in the dorsal ectodem
- the neural groove deepens as the two edges fuse to form the neural tube
- completely closed by about day 23 except for an opening at each en d
- the upper end closes on day 25 and continues to fold and develop, forming the brain
- the bottom end closes on day 27 and forms the spinal cord
Neural tube defects
- Spina bifida occulta
- meningocele
- myelomeningocele
- ancencephaly
Nerual tube defects
Spina bifida occulta
- incomplete fusion of the posterior vertebral arch
- all the neual contents are in there - more of a bony deformit
Neural Tube defects
Meningocele
- external protrusion of the meninges
neural tube defects
myelomeningocele
protrusion of the meninges and spinal cord
- similar to spinal cord injury
- presentation depending on the level of involvement
Neural tube defects
Anencephaly
- failure of upper most part of the Neural tube to close
- bain does not develop and the child is not verry functional
Spina bifida- often occurs with what?
- often have hydrocephalus: disruption of the CSF
- will have shunts that run ventroperritoneal
- VP shunt: avoid Crimping it or restrict the fluid moving through it
- squinting due to pressure or holding ears acting out is a sign of back up of fluid
Spina bifida occulta
clinical manifestations
- No neurologic dysfunction
- occasionally bowel and bladder distrubances
- foot weakness occur
Meningocele
clinical manifestations
- Rarely cause neurologic deficits
Myelomeningocele
clinical manifestations
- permanent neurologic impairments depending on the level of involvement
Hydrocephalus with SB clinical manifestations
- Type 1 or tpe 2 Arnold-Chiari malformation
- fetal repair has lowered rate of Chiari malformation and hydrocephalus