genetics

Question 1

autosomal dominance inheritance and examples of…

Answer 1

single mutated or abnormal gene from one parent overrides the matching normal gen from the other parent. inherited from affected parent. ex: osteogenesis imperfect, congenital myotonic dystrophy, neurofibromatosis

Question 2

autosomal recessive inheritance and examples of…

Answer 2

same recessive mutated gene is inherited, typically neither parent is affected and no family history. ex: cystic fibrosis, , spinal muscle atrophy and biochemical disorders.

Question 3

X linked recessive inheritance

Answer 3

only affects males while females are carriers. ex: hemophilia, duchenne muscular dystrophy.

Question 4

What does this represent: xp21gene dmd

Answer 4

x linked on the short arm (p) dmd gene=type of muscular dystrophy

Question 5

Common characteristics with genetic syndromes

Answer 5

hypotonia
microcephaly
failure to thrive?
dysmorphic features
GDD
intelectual disability

Question 6

Define difft types of structural choromosomal abnormalities

Answer 6

deletion, duplication, inversion, translocation-ex: cri-du-chat, Prader Willi Syndrome, Angelman syndrome, Williams syndrome

Question 7

Trisomy 21 is an example of a numerical or structure chromosomal abnormality?

Answer 7

numerical-non-disjunction error

Question 8

Describe clin pic of fragile x

Answer 8

inherits FMR1 gene on the long arm of the X chromosome is mutated. responsible for brain development. small section of the gene code repeats itself on a fragile area of the x chromosome. GDD, walks by 2, speech and motor and language delays. hypotonia, hypermobile, intellectual disability, ASD, SZ, poor coordination, impaired balance, poor motor planning.

Question 9

What type of inheritance syndrome do Rett’s and fragile x syndrome represent?

Answer 9

x linked dominant-only one needs to be inherited to have the disease

Question 10

failure to thrive

Answer 10

1. weight consistently below 3rd-5th% OR
2. progressive loss of weight to <3rd-5th % OR
3. decrease in percentile rank for height and weight in a short period

Question 11

numerical abnormalities

Answer 11

autosome or sex chromosome

non-disjunction error

Question 12

non-disjunction error

Answer 12

entire chromosome or sister chromatids don’t separate and go into different cells. problem occurs during meiosis or mitosis.

Question 13

Prader Willi syndrome

Answer 13

de novo parental deletion chromosome 15

Question 14

Cri-du-Chat

Answer 14

de novo deletion of chromosome 5

Question 15

Angelman Syndrome

Answer 15

de novo maternal deletion of chromosome 15

Question 16

Williams Syndrome

Answer 16

de novo deletion of chromosome 7

Question 17

Retts stage I

Answer 17

subtle slowing of development. 6-18 mos. days in gross motor. less eye contact. stage can last up to one year.

Question 18

Retts stage 2

Answer 18

rapid or gradual loss of acquired skills. ages 1-4. ASD like behaviors. hand movements lost–>wringing, washing, clapping. unsteady gait w/ wide BOS. toe walking. tremors

Question 19

Retts stage 3

Answer 19

can last many years. 2-10 years. apraxia, SZ, comm skills may improve, motor difficulties, mod-sever intellectual disability, hyperventilation/valsalva

Question 20

Retts stage 4

Answer 20

motor deterioration. reduced mobility. mm weakness, rigidity, spasticity, dystonia. NM scoliosis (75% by age 13). cognition, comm and hand skills generally DON’T decline.life expect. uncertain beyond 40. osteoporosis high risk for femoral fx.

Question 21

mitochondrial disorders

Answer 21

alterations of small mitochondrial DNA fragments that are inherited from the mother. mtDNA codes polypeptides involved with oxidative phosphorylation. can only be transmitted by the mother b/c zygote gets all its moitochondria from the egg. CNS and mm. affected b/c of large amounts of mitochondria found in tissues. myopathies, generalized weakness, decreased balance, exercise intolerance, encephalopathy, retinal degeneration.. can look like CP.