Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FOM Quiz 6 > 10/20 Genetics > Flashcards

10/20 Genetics Flashcards

1
Q

What are the effects of trisomy 18

A

edwards syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the three anisomy trisomy that is compatible with live birth?

A

Thri 18; Tri 13; Tri 21

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the symptoms of trisomy 16?

A

sever cns defects; congenital heart disease; low,rotated ears, small mouth prominent occiput; houshoe kidneys; rocker-bottom feet; hypertonia; cardiac and renal failure, common causes of death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the effect of trisomy 13?

A

Patau syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how many of the tri 13/18 are lost before birth?

A

90%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the feature of the pataue syndrom?

A

postaxial polydactyly; often omphalocele; and some midline defects (cleft lip or palate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is one eye called or other mid-line defects

A

holoprosencephaly –can be

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the gene that causes holoprosencephaly?

A

sonic hedge hog

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the take-away for tri 13/18 survival

A

although usually lethal, some tri 13/18 can survive and reach some developmental milestones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does occurance of trisomy 13/18 change with age of mother

A

they go up! esp. after 35

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where is most of the tri 13/18 come from –maternal or paternal?

A

from the maternal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the result of having only one X as a sex chromosome

A

Turner syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why does turner syndrome happen when you usually inactivate the x chromosome anyway?

A

there is about 15-20% of the ggenes on the inactive x chromo that are not inactive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the phenotype of terner syndrom?

A

reduced stature; webbed neck; shield shaped chest; gonadal dysgenesis; sterility; renal malformations; aortic coarctation; diminished spatial IQ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why reduced stature in turner syndrome

A

shox transcrition factor gene deleted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is cystic hygroma?

A

a large cyst associated with turner syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

where is the SHOX gene?

A

on the distal 2.6 Mb of X or the distal tip of the Y and escapes silencing in silencing the X chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how many of the turner syndrome conceptions are lost?

A

99% of them – acounts for 10-15% of first trimester miscarriages.

19
Q

How could a turner syndrome baby survive?

A

by being a mosaic where some of the cells lose one of the X chromosomes after fertilization.

20
Q

how can treat turner syndrome?

A

growth hormone treatment; estrogen replacement; gonadectomy; monitor for cardiovascular defects; psychiatric management when needed.

21
Q

what is the result of having XXY?

A

klinefelter sydrome

22
Q

Klinefelter syndrome phenotypes

A

increseased stature; hypogonadism; sterility; female habitus; gynecomastia; reduced IQ;

23
Q

what if there is XXX

A

then you have a rather mild phenotype of increased stature, hypertelorism; premature ovarian failure; slight IQ reduction; and wide set eyes.

24
Q

what if XYY?

A

then you get a slight phenotype of increased stature and slight IQ reduction.

25
Q

what percent of the numerical chromosome abnormalities are from the mother or father?

A

1-2% from the paternal; 20-25% are maternal gametes in origin

26
Q

what percent of the structural abnormalities are from paternal/maternal gametes?

A

5% paternal; 1% maternal

27
Q

what if fusion of long arms of acrocentric chromosomes 13 and 14? (missing 14 and very large 13 chromosome)

A

Robertsonian translocation.

28
Q

what is a acrocentric chromosme

A

a chromosome where the centromere is neat the tip of the chomosome and not in the middle: 13, 14, 21 etc.

29
Q

what happens if you have a robertsonian translocation of chromosome 21?

A

down syndrome!

30
Q

what is the difference in a balanced and not balanced robertsonian translocation

A

you get a net trisomy or monosomy or normal expression if it is balanced or not.

31
Q

why would it be important to know if the down syndrome is due to translocation or a true trisomey

A

the recurence is much higher with translocation

32
Q

what is a partial trisomy and monosomy and how can that happen?

A

reciprocal translocation: exchange between non-homologous chromosomes.

33
Q

what is the philedelphia chromosome and how does it happen

A

reciprocal translocation between 9 and 22.

34
Q

what does a philadelphia chromosome do?

A

causes chronic myelogenous leukemia by fusing the ABL proto-oncogene with the BCR promoter gene!

35
Q

what is the treatment for the philadelphia chromosome?

A

gleevac (imatinib) binds to BCR-ABL ATP binding site and stops it!

36
Q

what if there is a deletion of the short arms of 5?

A

then you get Cri-du-Chat (cry of the cat): 46,XX,del(5p); you get low IQ and small head etc.

37
Q

what if extra short arm of 5?

A

then you get a mild form of Cri-du-Chat! deletion is worse than duplication!

38
Q

how could a XX be a male?

A

by SRY gene placement on the X chromosome during male meiosis.

39
Q

What is FISH?

A

fluorescent label of specific gene probes that hybridize to target regions of DNA in a denatured strand of DNA. this highlights the genes and can easily show number or deletion of genes.

40
Q

what is comparative genomic hybridization.

A

you take a control DNA that is normal but with a flourescent marker and hybridize with test DNA with a different colored flourescent signal and then compare the result to see if you get any with just a test or just a control signal that would indicate extra or missing genes.

41
Q

what is a possible application of FISH

A

to make sure that you are implanting a good zygote in invetro implantiation.

42
Q

what are the advantages of FISH

A

done at any cell stage and can highlight abnormalities in higher resolution

43
Q

what is the basic application of CGH analysis of DNA?

A

to check for chromosomal deletions or duplications.

44
Q

what is a common patient to get checked with CGH?

A

children with any significant developmental delays.

FOM Quiz 6 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions