Genetic Disorders Flashcards
Genotype is..
entire genetic composition
Phenotype is…
expression of genes
Chromosome contains
DNA
DNA is made up of
nucleotide bases
Cytosine, thymine, adenine, and Guaninine
How many pairs of chromosomes; how many total?
23 pairs; 46 total
True/False
There are 22 pairs of autosomal chromosomes?
True
True/False
There is 1 pair of sex chromosomes?
True dat
What does this mean?
47, xx, +21
47= extra chromosome xx= female \+21= extra chromosome is on #21
What does this mean?
46, xy, -10q
46= correct number of chromosome xy= male -10q= chromosome #10 is missing its q arm
Monosomy means
When one chromosome of a pair is missing
Trisomy means
Presence of an extra chromosome
Deletion means
part of the chromosome is missing; part of the genetic code has been omitted
Translocation means
part of a chromosome has been detached and reattached its self to another chromosome
Trisomy 21
47xx+21 0r 47xy+21
Down syndrome
most common trisomy
Trisomy 18
47xy+18 OR 47xx+18
Edwards Sydrome
2nd most common trisomy with more serious organic malfunctions
Trisomy 13
47xy+13 OR 47xx+18
Patau syndrome
True/False
Does the risk of incident increase with age?
Does a bear shit in the woods?….yes
Down syndrome common physical features are..
upward slanted eyes, small oral cavity resulting in a protruding tongue (macroglossia), Epicanthal fold at the eyes, saddle nose, small ears
Common instability associated with down syndrome?
AA instability
clinical picture of Down syndrome?
1) Simplicity in convolutional pattern ( not so deep gyri and sulci)
2) reduced synaptogenesis
3) lack/delay of myelination
4) decreased # of small neurons
5) Structural abnormalities of neurons
6) increased # neurofibrillary tangles and senile plaques
7) MR
8) Microbrachyechaly ( flat skull A/P and wider M/L)
9) Cardiopulm abnormalities (valve issues)
Down syndrome, musculoskeletal clinical picture
1) hypotonia (low resistance to stretch, hang on Ligamentous structures)
2) Foot deformities
3) Hip sublux/dislocation
4) patellar instability
5) Scoliosis
6) AA instability
Down syndrome, Sensory deficits
1) Hearing loss
2) Strabismus (esotropia= eye turned out)
3) Cataracts
4) Chronic otitis media (ear infections)
5) Nystagmus
6) Myopia (near sighted)
AFP
Alpafitoprotein
Is Edward syndrome related to maternal age?
yeppers
what percentage of children survive past 1 year?
10%
true/false
seen more in females then males 3:1
the truth
Clinical picture of Edwards Syndrome
1) LBW, small stature
2) CV/GI/urogenital/skeletal malformations
3) Long narrow skull with misshapen ears
4) Tone abnormalities
5) profound MR
6) Leads to poor cerebellar function
true/false
Is Patau syndrome correlated with advanced maternal age?
dats da truth
Clinical picture of Patau syndrome
1) CNS/CV/MS/urogenital
2) severe-profound MR
3) An/microopthalmia - no eyes/small eyes
What percentage of babies survive past 3 years?
5%
Sec chromosome disorders are characterized by…
absent, extra, or damaged chromosomes
45XO is also known as
Turner Syndrome
Turner syndrome is only found in which Sex?
Females
True/False
Turner syndrome is the most common cause of spontaneous abortions
True
True/False
Turner Syndrome is correlated to advanced maternal age.
False
Physical features of Turner Syndrome
1) Webbed neck
2) Cubital valgus
3) dorsal edema of hands and feet
4) Hypertelorism (eyes wide set)
5) Epicantal folds
6) Ptosis
7) elongated ears
8) Growth retardation
Comorbidity w/ Turner Syndrome
1) Congenital heart disease
2) Kidney infection
3) Hearing loss
4) Decreased gustatory and olfactory
5) Defects in spatial perception and orientation
6) Average intellect– not cognitive impaired
7) Sexual infantilism
Skeletal abnormalities associated w/ Turner Syndrome
1) hip dislocation
2) Foot deformities
3) osteoporosis
4) Idiopathic scoliosis
47XXY is also known as
Klinefelter Syndrome
Klinefelter Syndrome is characterized
An extra X chromosome in males
Clinical picture of Klinefelter Sundrome
1) Testes fail to enlarge
2) Gynecomastia– breast development
3) Normal IQ (unlike Connor)
4) Sterility (probs like Connor)
Klinefelter Syndrome in severe karyotypes
1) severe MR
2) hypertelorism
3) Strabismus
4) cleft palate
5) radioulnar stenosis
6) genu valgus
7) malformed cervical vertebrae
8) pes planus
Fragile X syndrome is characterized by:
abnormalities w/ the X chromosome functioning; not missing parts, just parts don’t work right (like ehlers)
Clinical features of Fragile X syndrome are:
1) large head/ears/jaw
2) myopic
3) v-shaped palate
4) large testes
5) active (ADHD)/autistic
True/False
There is no intervention for Fragile X syndrome
true
True/False
Fragile X syndrome is only found in males
Truth
Partial deletion of a chromosome is…
where a section of the chromosome is missing
When is it usually deleted?
Replication process during meiosis
Which arm is the Q arm?
The long arm of the Chromosome
Which arm is the P arm?
The short arm of the chromosome
46XY-4p OR 46XX-4p is also known as?
Wolf-Hirschhorn syndrome
Which arm is effected by Wolf-Hirschhorn Syndrome?
the short arm of chromosome 4 (-4p)
True/False
Wolf-Hirschhorn is very rare, only 120 cases since 1992?
True
Clinical features of Wolf-Hirschhorn syndrome?
1) severe psychomotor and growth retardation
2) hypotonicity
3) microcephaly
4) hypertelorism
5) cleft lip/palate
6) heart malformation
7) hip dislocation
8) club feet
46XY-5p OR 46XX-5p is also known as?
Cri-du-chat syndrome; cry of the cat syndrome due to the high pitched cry at birth
Which arm is effected by Cri-du-chat syndrome?
the short arm of the 5th chromosome (-5p)
Clinical features of Cri-du-chat syndrome
1) high pitched cry
2) microcephaly
3) growth/mental retardation
4) hypertolerism
5) strabismus
6) tone abnormalities
7) scoliosis
8) hip dislocation
9) club feet
10) respiratory/feeding problems
46XY-15q OR 46XX-15q is also known as?
Prader Willi Syndrome
synophrys looks like?
unibrow
Early Clinical features of Prader Willi Syndrome?
1) hypotonia
2) expressionless face
3) waek cry
4) poor feeding
5) slow weight gain*
6) dysmorphic facial features
Late Clinical features of Prader Willi Syndrome?
1) improved mm tone w/ coordination and motor delays
2) persistent/compulsive appetite*
3) obesity
4) hypogonadism
5) mid/mod MR
6) maladaptive behaviors
Prader Willi Syndrome is associated with?
Lack of development of secondary sex characteristics and FTT
Autosomal Dominant Disorders results from?
abnormality or mutation in a single gene
True/False
Abnormal or mutated genes override the normal allele inherited from the other parent.
True
Pathophysiology of Osteogenesis Imperfecta
deficits in collagen synthesis
True/False
The children can be born with Fx
true
Clinical picture of Osteogenesis imperfecta
1) types I-IV
2) brittle bones
3) hyperextensible ligaments
4) blue teeth
5) skeletal deformities
6) deafness
7) Small stature/limbs
Pathophysiology of Tuberous Sclerosis
Spontaneous mutation related to increased paternal age
Clinical picture of Tuberous Sclerosis
Triad of symptoms:
1) seizures
2) MR
3) sebaceous adenomas
sebaceous adenomas are…
a cutaneous condition characterized by a slow-growing tumor usually presenting as a pink, flesh-colored, or yellow papule or nodule.
Pathophysiology of von Recklinghausen Disease (neurofibromitosis)
spontaneous mutation or family related
Clinical picture of von Recklinghausen Disease
cafe au lait spots, neurofibroma, MR, seizures
Pathophysiology of Huntington’s Chorea
Gross atrophy of corpus striatum, neuronal degeneration in caudate nucleus/putamen/deep nuclei and frontal cortex.
Clinical picture of Huntington’s Chorea
Choreic movements, variable progression and regression; involuntary and uncontrolled movements
True/False
There is a cognitive decline as the disease progresses
True
Huntington’s Chorea develops
later in life 30s,40s,50s
Pathophysiology of Charcot-Marie-Tooth disease
Hereditary motor and sensory neuropathy or peroneal muscular atrophy
Clinical picture of Charcot-Marie-Tooth disease
Pes cavus
hammer toe
foot drop
hip/knee flex w/gait to compinsate
What can be done to CMT-2
can strengthen and lengthen but cant reverse damage
What is an autosomal recessive disorder?
allele inherited from each parent is abnormal. The combo of the 2 alleles results in the disorder.
Do the parents need to have the disorder, in an autosomal recessive disease?
Negative ghost rider
Pathophysiology of Hurler Syndrome
error in metabolism
Clinical picture for Hurler Syndrome
appear normal at birth w/ symptoms progressing over 1-3 y/o. Seeing:
1) facial deformities
2) mental and physical deterioration
3) early death secondary to cardiac pathology.
Management of Hurler Syndrome
no medical management, just supportive
Pathophysiology of Phenylketonuria (PKU)
Absence of phenylalanine hydroxylase prevents conversion of phenylalanine to tyrosine.
Clinical picture of Phenylketonuria (PKU)
untreated causes MR/GR, seizures and movement disorders
