Week 1: Cyto, Aneuploidy, Deletions Flashcards Preview

Amy's Updated Board Exam Deck > Week 1: Cyto, Aneuploidy, Deletions > Flashcards

Flashcards in Week 1: Cyto, Aneuploidy, Deletions Deck (53)
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1
Q

5 main features of T21

A

Hypotonia, ID, flat facial profile, CHD, GI anomalies

2
Q

Most common genetic cause of T21

A

Nondisjunction

3
Q

Mosacism is always a _____ event

A

Mitotic

4
Q

RR for nondisjunction T21

A

1% OR maternal age risk

5
Q

5 major features of T18

A

Hypertonia, clenched fist with overlapping 3rd and 4th finger, rocker-bottom feet, ID, hernia

6
Q

RR for T18

A

Less than 1% (since most SAB)

7
Q

5 major features of T13

A

(Midline) HPE, CL+P, polydactyly, omphalocele, ID+ seizures

8
Q

RR for T13

A

Less than 1% (since most SAB)

9
Q

5 major features of 22q11

A

Velopharngyeal incompetence, CHD, asymmetric crying facies, immunodeficiency, hypocalcemia

10
Q

Is 22q usually de novo or inherited

A

de novo

11
Q

5 major features of XXY

A

Hypogonadism, infertility, lower IQ than sibs, behaviour problems, gynecomastia

12
Q

Treatment for XXY

A

Testosterone supplementation

13
Q

5 major features of XO

A

Short stature, gonadal dysgenesis, webbed neck, CHD, transiet congenital lymphedema

14
Q

Treatment for XO

A

Estrogen replacement therapy

15
Q

Risk for 45, X/ 46, XY Mosaics

A

Gonadoblastoma

16
Q

What is used to stop the cell cycle in metaphase when making a karyotype

A

Colchicine

17
Q

Best uses for FISH

A

Partial/full aneuploidy–but you must known what you are looking for

18
Q

Array CGH cannot detect

A

Balanced translocations, triploidy

19
Q

SNP-array is useful for detecting:

A

Consanguinity (ROHs), triploidy, UPD

20
Q

4 posible gametes for reciprocal translocation carrier

A

Normal, Balanced, Unbalanced (two forms)

21
Q

3 major features of Cri du Chat

A

Cat-like cry, microcephaly, low birth weight

22
Q

Where is deletion in Cri du Chat

A

5p

23
Q

3 major features of Wolf Hirschhorn

A

Greek warrior helmet appearance, FTT, ID

24
Q

Where is deletion in Wolf Hirschhorn

A

4p16.3

25
Q

3 major features of 1p36.3 del

A

severe ID, seizures, behaviour problems

26
Q

Where is deletion in 1p36.3

A

1p36.3

27
Q

3 major features of William’s Syndrome

A

Elfin face, outgoing personality, supravalvular aortic stenosis

28
Q

Where is deletion in William’s Syndrome

A

7q11.23

29
Q

T/F: X-inactivation affects all genes

A

False

30
Q

2 major features of Miller Dieker Syndrome

A

Type 1 lishencephaly, dysmorphic facies

31
Q

Where is deletion in Smith Magenis

A

17p11.2

32
Q

3 major features in Smith Magenis

A

Self-destructive behaviour, peripheral neuropathy, ID

33
Q

Deletion in Prader Willi

A

15q11-q13

34
Q

What parent’s copy is missing in PWS

A

Dad

35
Q

What parent’s copy is missing in Angelman

A

Mom

36
Q

Where is deletion in Angelman

A

15q11-q13

37
Q

3 major features of Prader Willie

A

Infantile hypotonia, hyperphagia, hypogenitalism

38
Q

3 major features of Angelman

A

Seizures, Unusual laughter, ataxic gait

39
Q

Where is duplication in BWS

A

11p15

40
Q

3 major features in BWS

A

Macrosomia, Macroglossia, Omphalocele

41
Q

Alternate segregation usually leads to balanced or unbalanced gametes?

A

Balanced

42
Q

Adjacent segregation usually leads to balanced or unbalanced gametes?

A

Unbalanced

43
Q

Centromeres in Adjacent 1

A

Unlike centromeres travel together

44
Q

Centromeres in Adjacent 2

A

Like centromeres travel together

45
Q

Tertiary 3:1 Segregation

A

2 normal chromosomes; 1 translocation chromosome

46
Q

Interchange 3:1 Segregation

A

2 translocation chromosomes; 1 normal chromosome

47
Q

List afrocentric chromosomes

A

13, 14, 15, 21, 22, Y

48
Q

RR if mom passes t(13;21)

A

15%

49
Q

RR if mom passes t(14;21)

A

10%

50
Q

RR if mom passes t(21;22)

A

10%

51
Q

Paracentric Inversion

A

Breaks in either short arm or long arm, no centromeres involved

52
Q

Pericentric Inversion

A

Break in the short arm and long arm, centromeres involved

53
Q

Inversions in what chromosomes are considered normal variation?

A

1, 9, 16, Y