Genetic Diseases Flashcards
(85 cards)
1
Q
give some examples of purely genetic diseases
A
CF, sickle cell
2
Q
give some examples of purely environmental diseases
A
mercury poisoning
3
Q
give some examples of combo genetic/environmental diseases
A
DM type II
HTN
4
Q
What are the 3 minimum competencies of PT w/ genetic diseases?
A
- appreciate one’s limitations in genetics and expertise
- understand psychosocial and ethical implications of genetic service
- know when and how to make referral
5
Q
When to refer:
Family history of…
A
- dysmorphology
- brain malformations
- epilepsy
- abnormal CT, EEG
- abnormal tone
- weakness, motor control, discoordination
- delated development
- sensory disturbances
6
Q
T/F:
Children w/global DD should be referred even in absence of dysmorphism
A
True
7
Q
Monogenic
A
Mendelian inheritance-single gene involved
8
Q
Polygenic
A
complex inheritance pattern-
many genes involved
9
Q
Cytogenetic
A
involves large scale changes in chromosomes
10
Q
genotype
A
refers to individual alleles and precise genetic makeup
11
Q
phenotype
A
physical or physiological manifestation of genotype
12
Q
T/F:
people with the same genotype present with the same phenotype
A
False
Two people can have same genotype (down syndrome) but have different presentation (phenotype)
13
Q
What are the 4 categories of genetic disorders?
A
- chromosomal
- single gene
- multifactorial
- mitochondrial
14
Q
Chromosomal disorders
A
Altered structure or number
- includes deletions, inversions, duplications, and translocations
- 10-15% of human conceptions but 1/160 births
(leading cause of miscarriage)
15
Q
translocations
A
part of the chromosome is translocated to be part of an other chromosome
16
Q
Alterations in number:
polyploidy
A
complete extra set
all are lethal
17
Q
Alterations in number:
aneuploidy
A
absence (monosomy) or duplication (trisomy) of a chromosome in a cell.
usually only one chromosome affected.
monosomies rarely survive
18
Q
Alterations in number:
mosaicism
A
most are due to a fully trisomy conception followed by loss of extra chromosomes during mitosis.
milder clinical manifestation
19
Q
T/F: you can survive without a Y chromosome
A
True
type xo
20
Q
T/F: you can survive without an X chromosome
A
False
21
Q
Alterations in structure:
Deletion
A
caused by chromosome break
22
Q
Alterations in structure:
Translocation
A
interchange of genetic material between nonhomologous chromosomes
23
Q
Alterations in structure:
Reciprocal translocation
A
2 breaks in different chromosomes w/equal exchange.
Normally carriers but offspring have disease
24
Q
General characteristics of chromosomal abnormalities
A
- most associated w/ developmental delay and cog impairment
- large # of genes involved w/CNS development
- delayed growth
- congenital malformations
25
down syndrome, edwards syndrome, and patau syndrome are all associated with:
advanced maternal age
26
Down Syndrome:
| most common form
trisomy 21
27
Down Syndrome:
| Phenotypic features
Hypoplasia common
| Craniofacial features
28
Down Syndrome:
| Craniofacial features
1. inner epicanthal folds
2. upward slanting palpebral fissures
3. flat facial profile
4. aplasia/hypoplasia front sinuses
5. anomalous ears
6. low nasal bridge
7. shortened palate
8. maxillary and dental hypoplasia
9. irregular tooth placement
29
T/F: sinus and ear infections are common w/Down Syndrome
True
30
Down Syndrome:
| MSK/Connective tissue
1. Diastasis recti
2. joint hypermobility
3. hypoplastic pelvis w/shallow acetabular angle
4. atlantoaxial instability
5. wide gap between toes 1 and 2
6. simian creases
7. Delated skeletal maturation rate
31
Down Syndrome:
| hypermobility+hypoplastic pelvis+shallow acetabular angle =
hip dysplasia, hip disolcation/subluxation
32
Down Syndrome:
| atlantoaxial instability leads to
risk of SC compression
33
Down Syndrome:
| linear growth deficits are greatest between...
6 and 24 months
mostly due to leg length reduction
34
T/F: 1/3 of Down Syndrome patients are overweight by age 3
True
35
Down Syndrome:
| Eyes/Vision
1. iris speckling
2. myopia
3. nystagmus
4. strabismus
5. tear duct blockage
36
Down Syndrome:
| Ears/hearing
1. conductive hearing loss
| 2. sensorineural or mixed hearing loss (roughly 78%)
37
Down Syndrome:
| CV
CHD is most common health problem with 40% having malformations
1. ventricular septal defect
2. patent ductus arteriosus
3. tetralogy of Fallot
38
Down Syndrome:
| GI
1. duodenal stenosis/atresia
2. imperforate anus
3. Hirschprung's disease
39
Hirschprung's disease
some paralysis in the intestines. can require colostomy bag
40
Down Syndrome:
| Neurologic
1. ID
2. mild microcephaly
3. hypotonia
4. early onset Alzheimer's
5. small cerebellum and brainstem
6. reduction of neurons and dendritic spines
7. increased latency of response
8. prolonged primitive reflexes
9. delayed emergence of righting reaction
41
Down Syndrome:
| Immunologic
```
suppressed immune systems
at risk for:
- leukemia
- chronic rhinitis
- chronic conjunctivitis
- fluid in middle ear
- ringworm and other rashes spread.
```
42
Down Syndrome:
| Life expectancy
55
43
Down Syndrome:
| Thyroid dysfunction
1. hyper and hypothyroidism with aging. Hypo more common (40% of total)
2. untreated hypothyroidism can mimic cog decline or early alzheimers
44
Down Syndrome:
| hypothyroid symptoms
- mimic cog decline/early alzheimers
- decreased energy
- decreased motivation
- weight gain
- constipation
- bradycardia
- dry skin
45
Down Syndrome:
| Mitral prolapse
46-57%
- can lead to endocarditis, CVA, HF
- can occur w/o prior cardiac findings
- early signs: fatigue, weight gain, dyspnea, bil crackles don't clear w/cough, 3rd heart sound
46
Down Syndrome:
| Premature aging may lead to
early MSK disorders associated w/elderly
- hip dysplasia w/dislocation
- foot pronation
- osteoporosis
47
T/F:
| Almost all adults w/ Down Syndrome over age 40 demonstrate Alzheimer's Disease neuropathology
True
48
T/F:
| mental illness occurs in approximately 10% of all adults w/Down Syndrome
False
| 30%
49
Turner Syndrome (45,x) characteristic impairments
1. sexual infantilism
2. congential webbed neck
3. cubitus valgus
others:
- dorsal edema hands/feet
- hypertolerorism
- epicanthal folds
- ptosis upper eyelids
- elongated ears
- shortening of hand bones
50
Turner Syndrome:
| skeletal anomolies
1. hip dislocation
2. pes planus
3. pes equinovarus
4. dislocated patella
5. deformity of medial tibial condyles
6. scoliosis
51
Marfan Syndrome
Mutation of gene coding for fibrillin protein leads to disruption of connective tissue in skeleton, eyes, and CV system
52
Marfan Syndrome:
| Skeletal symptoms
1. long limbs, fingers, and toes
2. hyperextensible joints
3. deformed chest
53
Marfan Syndrome:
| Eye symptoms
dislocated lenses due to lax suspensory ligaments
54
Marfan Syndrome:
| CV symptoms
1. aortic dilation w/valve regurgitation
| 2. aneurysm (dissecting)
55
Cri-du-Chat
1. (46, XY, del5p)
2. Low birth weight
3. Hypotonia
4. feeding difficulties
5. microcephaly
6. micrognathia
7. clumsiness
8. hyperactivity
9. mod-sever cog impairments
will have "cat like cry" as infants
56
Prader Will is inherited from the _ while Angelman Syndrome is inherited from the _
father, mother
57
Prader Willi:
| infancy
- failure to thrive
- respiratory and feeding difficulties
- severe hypotonia
58
Prader Willi:
| by 2 y.o.
1. excessive eating may start
2. obesity concern
3. tone improves w/walking
59
Prader Willi:
| Behavioral issues
1. temper tantrums
2. stubbornness
3. obsessive-compulsive
60
T/F: Prader Willi has a wide range of cognition, from low normal to severely impaired
True
61
Angelman Syndrome
1. puppet like gait
2. subtle dysmorphic facial features
3. frequent inappropriate laughter
4. ataxia
5. seizure disorder
6. sleep disorder
62
Williams Syndrome
Disturbance in elastin gene
1. CV disease
2. elfin like face
3. ADHD, LD, mild cog impairments
4. decreased visuospatial skills
5. laxity with later compensations
6. sensory defensiveness
7. tend to be musically talented
63
What are the 3 types of Single Gene Disorders?
1. Autosomal Dominant
- osteogenesis imperfecta
- tuberous sclerosis
- neurofibromatosis
2. Autosomal Recessive
- CF
- Hurler Syndrome
- PKU
- SMA
3. Sex-Linked
- hemophilia A
- Fragile X
- Lesch-Nyhan
- Rett
64
Fragile X Syndrome
- Leading hereditary cause of developmental learning disorders
- boys 2x as likely as girls
- expansion of a CGG repeat in FMR1 gene leads to gene inactivation
65
Muscular Dystrophy
- group of hereditary myopathies
- progressive muscle weakness, deterioration, destruction, and regeneration of muscle fibers
- muscle fibers gradually replaced by fibrous and fatty tissues
66
Muscular Dystrophy:
| Becker
1. 5-10 y.o
2. X-linked
3. Slowly progressive
4. maintains walking past early teens
5. life span into 30s
67
Muscular Dystrophy:
| Congenital
1. At birth
2. Recessive
3. typically slow but variable
4. shortened lifespan
68
Muscular Dystrophy:
| Congenital/myotonic
1. at birth
2. dominant
3. typically slow
4. significant intellectual impairment
69
Muscular Dystrophy:
| Child onset facioscaphum
1. first decade
2. dominant/recessive
3. slowly progressive loss of walking in later life
4. variable life expectancy
70
Muscular Dystrophy:
| Emery-Dreifus
1. Childhood to early teens
2. X-linked
3. Slowly progressive cardiac abnormality
5. normal life span
71
Rett Syndrome
1. progressive
2. x-linked: almost exclusively in females (males rarely survive)
3. normal development up to 6-18 months
4. may see mild hypotonia, placid personality, and weak suck and cry
5. head circumference decelerates from 3-48 months
72
Rett Syndrome progression
Short period in which development stagnates followed by rapid regression in motor, language, and psychosocial functions
After rapid deterioration, becomes stable
73
Rett Syndrome Symptoms
1. loss of purposeful hand movements replaced w/hand wringing
2. gait/truncal ataxia
3. tremors
4. apraxia
5. autistic-like behavior
6. bruxism, breathing irregularities
7. GERD
8. impaired bowel mobility
9. LE vasomotor changes
10. severe impaired language, cognition, and seizures
11. dystonia in hand/foot deformities and kyphoscoliosis
12. osteoporosis (early)
74
Retts Syndrome:
| when to expect fits of screaming and crying
18-24 months
75
Metabolic disorders involve
1. amino acid metabolism
2. carbohydrate metabolism
3. lysosomal storage
4. urea cycle disorders
76
Phenylketonuria
most common monogenic amino acid disorder
- autosomal recessive
- phenylalanine and phenylpyruvate accumulare in blood, appear in urine
- symptoms include severe mental retardation
77
Galactosemia
most common monogenic carbohydrate disorder
clinical signs:
- failure to thrive
- hepatic trouble
- cataracts
- development delay
78
Lysosomal Storage Disease
- deficiency of a lysosomal enzyme involved in breakdown of macromolecules within lysosomes
79
Lysosomal Storage Disease:
| Sphingolipidosis
involves a defect in degredation of sphingolipids.
leads to multiorgan dysfunction
80
Neurofibromatosis Type 1
mutation of NF1 leads to loss of cell differetiation and uncontrolled cell growth
81
NF1:
| symptoms
1. cafe-au-lait spots
2. fibromas
3. Lisch nodules in eyes
82
traits in which variation is thought to be caused by combined effects of multiple genes
polygenic traits
83
when environmental factors are also believed to cause variation in that trait
multifactorial
84
Autism
severe neurodevelopmental disorder in which 15 susceptibility loci have been identified that each make additive contribution to phenotype
85
Type 1 DM
thought to be autoimmune disorder involving immune destruction of beta cells
