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Flashcards in Genetic Pathologies Deck (72)
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1
Q

Non-disjunction has higher frequency in males or females?

A

Females

2
Q

What is the consequence of mutation in the 3’ UTR?

A

Disturbed translation and localization

3
Q

What are the genetic causes of Prader-Willi syndrome?

A
Paternal deletion (70%) - del(15q11-13)
Maternal UPD of chromosome 15 (28%)
Wrong imprinting (>2%)
4
Q

A genetic defect can be expressed all over the body of a males while in females it will be expressed in some parts and some part it won’t. This is example of?

A

Chromosome inactivation

5
Q

What are the causes for Down syndrome?

A

Almost always due to meiotic non-disjunction; small chance by Robertsonian translocation (centric fusion), mostly t(14;21)

6
Q

Robertsonian translocation (centric fusion) can occur in which chromosomes?

A

13, 14, 15, 21 and 22 (acrocentric chromosomes)

7
Q

Ring chromosome can occur in which chromosomes

A

Any chromosome

8
Q

What are the symptoms of Turner syndrome?

A

Short stature, webbed neck, sexually undeveloped

9
Q

What are the chances a kid will inherited an AR disease from his parents, if both are heterozygote healthy (carriers)?

A

25%

10
Q

Marfan syndrome- name the inheritance mode, the defected gene and protein

A

Autosomal dominant, FBN1 gene and fibrillin protein

11
Q

Fragile X syndrome- name the inheritance mode, the defected gene and the mutation

A

X-linked dominant, FMR1 gene and it is a triplet repeat disease (more than 200 triplets of CGG)

12
Q

What are the symptoms of Angelman syndrome?

A

Developmental retardation
Compulsive movements
Inappropriate laughter (“happy puppet syndrome”)
Poor / incomplete speech ability

13
Q

Name all the chromosome structural aberrations

A
Deletion (interstitial or terminal)
Duplication
Translocation (can be Robertsonian)
Insertion
Inversion
Ring chromosome
Isochromosome
14
Q

Give an example of loss of imprinting (LOI) in a cancer

A

Loss of IGF2 imprinting in colon cancer (usually, only the maternal is expressed but in colon cancer the paternal is also expressed due to LOI)

15
Q

What is the consequence of mutation in the polyadenylation site?

A

Decreased mRNA stability

16
Q

What is the consequence of anaphase bridge?

A

Breakage of the chromosome, can be seen as acentric fragment (micronucleus)

17
Q

How does red-green color blindness is inherited?

A

X-linked recessive

18
Q

What is the consequence of exon mutation?

A

Changed amino acid or truncated protein (i.e., stop codon)

19
Q

Huntington’s disease manifest earlier and more severely in successive generation. This is example of what?

A

Anticipation (a special type of variable expressivity)

20
Q

Which 2 mutations occur in most of the cancers (60%)?

A

Ras (oncogene) and P53 (tumor suppressor) mutations

21
Q

Which gene is defected in achondroplasia?

A

FGF3 gene

22
Q

What are the chances a kid will inherited an AD disease from his parents, if one is heterozygote (sick) and the other is healthy?

A

50%

23
Q

Define in-frame mutation

A

Triplet nucleotide insertion or deletion that will keep the reading frame

24
Q

What is the reason for multipolar division?

A

Atypical duplication and division of the centrosome

25
Q

What are the genetic causes of Angelman syndrome?

A
Maternal deletion (70%) - del(15q11-13)
Paternal UPD of chromosome 15 (4%)
Wrong imprinting (~8%)
UBE3A mutation (~8%)
26
Q

Chimerism can occur due to?

A

Double fertilization
Dizygotic twins
Gene manipulation

27
Q

Define frame shift mutation

A

Insertion or deletion of nucleotide bases that change the reading frame

28
Q

What is the most common translocation in C-myc incase of Burkitt’s lymphoma? what are the others?

A

Reciprocal translocations- most common is t(8;14), others are t(2;8) and t(8;22)

29
Q

What is the consequence of intron mutation?

A

Errors in splicing or in regulation

30
Q

What is the inheritance pattern of adult PKD?

A

AD (remember- ADult is AD)

31
Q

Replications errors are higher in males or females?

A

Males

32
Q

Triplet repeat of CAG is the background of which disease?

A

Huntington’s disease

33
Q

Which gene is the most common defected in Waarndenburg syndrome?

A

Pax3 gene

34
Q

How many Barr bodies are in a Turner syndrome patient’s cell?

A

0 (there is no Barr body in Turner syndrome)

35
Q

What is the consequence of mutation in the 5’ UTR?

A

Decreased protein synthesis (translation)

36
Q

What is the mechanism of anaphase bridge?

A

Merotelic attachment of kinetochore microtubules- one chromatid is pulled from the two poles while the other chromatid is pulled only from one pole

37
Q

What is the reason fragile X syndrome is more common in males?

A

Reduced penetrance in females (although it is inherited in X-linked dominant pattern)

38
Q

Which protein is mutated in androgen insensitivity syndrome (AIS)?

A

Testosterone receptor

39
Q

A cystic fibrosis patient has a deletion of F508 in one chromosome and a point mutation in the other allele (of the homologue chromosome). This is example of what phenomenon?

A

Complex heterozygoty

40
Q

What will happen if mitosis is not followed by cytokinesis?

A

Multinuclear (giant) cell will be formed

41
Q

What is the mutation type in the background of Becker muscular dystrophy?

A

In-frame mutation (small deletion of trinucleotide repeat)

42
Q

What are the symptoms of Prader-Willi syndrome?

A

Obesity
Small hands and feet
Underdeveloped genitalia
Mild mental retardation

43
Q

What are the most important symptoms of Klinefelter syndrome?

A

Sexual immaturity (no sperm), breast swelling

44
Q

What is the inheritance pattern of infantile PKD?

A

AR

45
Q

What is the mutation type in the background of Duchenne muscular dystrophy?

A

Frame-shift mutation (large deletion)

46
Q

What is the consequence of mutation in the promotor region?

A

Altered transcription

47
Q

What are the symptoms of triploidy?

A

It is lethal (result in death; no symptoms)

48
Q

What is the result of mutation in sonic hedgehog gene (SHH)?

A

Cyclopia (rare form of holoprosencephaly), in which the eyes due not separate

49
Q

Nucleotide Excision Repair - What genetic error is it aimed to fix?

A

Thymine dimer

Formed by UV exposure

50
Q

Base Excision Repair - What genetic error is it aimed to fix?

A

Uracil created by deamination

of cytosine

51
Q

Mismatch Repair - What genetic error is it aimed to fix?

A

Bases mismatch (e.g. C with A)

52
Q

What is the Mitochondrial DNA repair system?

A

There is no mitochondrial DNA repair.

53
Q

What is the gene mutation that is leading to Ataxia telangiectasia? Inheritance pattern?

A

ATM (DNA repair)

AR

54
Q

What is the gene mutation that is leading to Li-Fraumeni syndrome? Inheritance pattern?

A

TP53

AD

55
Q

What is the gene mutation that is leading to Fanconi Anemia ?

A

BRCA1

56
Q

Huntington’s disease is an example of a Poly________ disease.

A

Huntington’s disease is an example of a Polyglutamine disease.

57
Q

Fragile X syndrome is an example of a Poly________ disease.

A

Fragile X syndrome is an example of a Polyarginine disease.

58
Q

What are the groups of repeats included in the VNTR?

A

Minisatellite (E.g Telomere) and Microsatellite

59
Q

What are the two kinds of Interspersed repeats (transposons)?

A

SINEs and LINEs

60
Q

What is a Transition?

A

Point mutation (Change in nucleotide) where the following can happen:
Pyrimidine to Pyrimidine (e.g. C to T)
Purine to Purine (e.g. G to A)

61
Q

What is a Transversion?

A
Point mutation (Change in nucleotide) where the following can happen:
Pyrimidine to Purine (or vice versa)
62
Q

What will be the result of a del(5p-)?

A

Cri-du-chat syndrome

63
Q

What will be the result of a del(22q11.2)?

A

DiGeorge syndrome

64
Q

What will be the result of a t(9;22)(q11;q34)?

A

Philadelphia chromosome - CML

65
Q

What will be the result of a t(8;14)?

A

Burkitt lymphoma (Due to EBV infection)

66
Q

What will be the result of a inv(9) (p11q13)?

A

Major cause of frequent abortions

67
Q

X-Linked Hypophosphatemia:

Gene and Mode of Inheritance?

A

X-Linked Hypophosphatemia:

PHEX gene and XD

68
Q

Albinism:

Gene and Mode of Inheritance?

A

Albinism:

Tyrosinase and AR

69
Q

Leber’s hereditary optic neuropathy:

Gene and Mode of Inheritance?

A

Leber’s hereditary optic neuropathy:

ND4 and Mitochondrial

70
Q

Waardenburg syndrome:

Mode of Inheritance?

A

Waardenburg syndrome: AD

71
Q

Sickle cell disease: Gene

A

Sickle cell disease: Beta-Globin

72
Q

Amelogenesis imperfecta:

Gene and Mode of Inheritance?

A

Amelogenesis imperfecta:

AMELX and Multiple forms dependent on gene