Brainscape's Knowledge GenomeTM

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


See full index

Undeleted > Clinical cytogenetics > Flashcards

Clinical cytogenetics Flashcards

1
Q

3 common reasons for chomosomal studies

A
  1. neonatal and peds - testsing
  2. infert. and prenatal - 50% of aborts have abnormality
  3. leukemia and lymphoma - diagnostic and prognostic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

def. chromatin

A

uncondensed DNA

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

how is karyotype organized

A

by size and shape

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

what type of cells must be used for karyotype

A

dividing

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

what is G banding and result

A

technique where treat with 2 dyes and then get band pattern - most genes in light band

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

what is nomenclature for Downs’ susndrom

A

47, XY, +21

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

what are replication phases of meiosis

A

S phase - chomosomes replicate
prophase 1 - maternal and paternal chromos recombine
telophase 1 - chormosomes separate
M2 - sister chromatids separate - 4 gametes

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

what is major cause of aneuploidy

A

nondisjunction

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

what is result of non-disjunction at M1

A

2 x n+1

2 x n-1

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

what is result of non-disjunction at M2

A

2x n
1 x n +1
1x n-1

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

what is klinefelters

A

47, XXY

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

2 causes of kline

A
  1. non-dis in M1 of dad

2. non-dis in M2 of mom

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

phenotype of klinefelter

A
  • tall
  • narrow shoulders
  • small testes
  • gynecomastia
  • T def.
  • azoospermia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is turner

A

45,X

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

what is turner rare

A

very high rate of spont. abortions

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

features of tri 18

A

mental ret, failure to thrive, sever heart defects, hypertonic, low set ears, short sternum

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

features of tri 13

A

severe mental, poor gorwth, CNS malform,

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

what is triploidy

A

3 sets of chromo

  • dispermy common
  • non-viable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

3 types of specimens for chromo analysis and how they must be treated and time periods

A

all at 37C

  1. peripheral bloods - 72hrs
  2. monolayer cell cultures - skin, abortus, amniotic fluid - 1 to 2 weeks
  3. bone marrow or lymph nodes 1-24hr
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

2 types of invasive prenatal testing

A
  1. amnicenticis - 16-18wk - fine needle through abdo wall and into uterus
  2. chorionic villus sampling - 10-12 weeks - cells from the developing placenta are tested instead of fluid through vagina or abdo wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

5 indications for invasive testing

A
  1. high risk preg
  2. late maternal age
  3. abnormal US
  4. previous trisomy 21
  5. carrier of a rearrangement
    6, fam Hx
22
Q

adv. and dis adv. of amnio over CVS

A

adv. - less miscarirgae, better chromo length, less mosaicism,
dis - done later

23
Q

when to suspect mosasicm

A

highly variable phenotype, can be hard to detect unless there are pigment variations

24
Q

what does 46,xx,del(18)(q23)dn mean

A

deletion of long arm of chromosome 18 new (denovo)

25
Q

why does a chromo deletion cause a defect

A

haplotype insufficiency - need enough - generally dose dependent

26
Q

what is cri du chat

A

5p deletion - as more is cut it become more severe

27
Q

types of rearrangments (5)

A
  1. deletion
  2. duplication
  3. translocation
  4. ring chromo
  5. inversion
28
Q

can chromo rearrangment be inherited

A

yes

29
Q

what is reciprocal tranlocation and effect

A

switch of both ends of two different chromo - carrier is usally fine, but can them pass down and they are at risk for imbalance

30
Q

example of writing cytogenic translocation

A

46,XX, t(9;10)(p22;p15)

31
Q

what does breakpoint position determine

A

the amount of abnormality, the more that is switched, the less likely they are to be viable

32
Q

2 reproductive options for carriers of translocations

A
  1. genetics - prenatal testing and can terminate preg

2. fertility - donor egg or sperm

33
Q

how common are chromo abnormalityes at birth

A

rare - less than 1%

34
Q

what is CML translocation

A

somatic - in adulthood

- transfer ABL onto BCL gene - tyrosine kinase activity

35
Q

what is the cytogenic alternative to G-banding

A

FISH - used to detect abscence or presence of a particular sequence of chromos

36
Q

what are adv. of fish

A
  • can detect low level mosaisicm
  • fast
  • specific
  • can do 100s at once
37
Q

what is a genomic disorder

A

small recurrent deletions or duplications

- happen frequently and distinct enough to call a syndrome

38
Q

what is size of genomic disorders

A

very small - too small to see with G banding

- need FISH or microarray

39
Q

what are segemental duplications

A

normal structure in chromo that are repeated mobile elements

40
Q

sig. of segmental duplications

A
  • was evolotionary

- cause of possible genomic disorders

41
Q

def. non-homologous allelic recomb.

A

unequal crossing over that causes both deletions and duplications

42
Q

how to detect genomic disorders

A

microarray - 1000s of FISH at once

43
Q

what is degeorge

A

micro deletion 22q11.2

  • truncus arteriosus
  • facial features
  • infection prone
  • variety of phenotype
44
Q

what is comparison syndrome of deletion duplication

A

dup. - william - cocktail party

del - speech delay, schizoid

45
Q

what is generally better

A

duplication

46
Q

how much of genome coded proteins

A

2%

47
Q

what are Canadian guidelines for child with dev. delay

A

genomic micro array - trio with child and parents

48
Q

what is Gbanding still first test for (4)

A
  1. aneuploidy syndromes
  2. sex chromos
  3. suspected mosaicism
  4. infet., multiple miscarriage
49
Q

see methodology chart

A

see

50
Q

what is impact of micro array on clinical genetics

A
  1. improve diagnosis, treatment, prevention
  2. discover new syndromes
  3. insght into the genes and dev. pathways that lead to harm
51
Q

what is seen in normal people

A

high degree of copy number variants

52
Q

4 possible outcomes of microarray analysis and interpretation

A
  1. normal or benign - harmless
  2. patho or likely patho - trioanalysis reccomneded - known to cause problems
  3. variant of unknown sig. - trioanalysis reccomend
  4. unexpected finding -

Undeleted (589 decks)

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