Genetic Mutations And Polymorphisms Flashcards Preview

Biochem 4 > Genetic Mutations And Polymorphisms > Flashcards

Flashcards in Genetic Mutations And Polymorphisms Deck (79):
1

Mutation of the CFTR gene results in:

Chloride channel does not reach plasma membrane disrupting the movement of chloride ions

3

One of the specific mutations for Tay-Sachs involves:

A point mutation G to C that alters the proper slicing of the mRNA at the boundary between exon 12 and intron 12 of hexA gene

4

Charcot-Marie-Tooth disease (CMT) specific genetic mutation

Duplication of 1.5 million base pairs of chromosome 17 produced by misalignment during recombination. All genes are present as three copies

5

Charcot-Marie-Tooth disease alters the ___________ gene and is a ___________ disorder

PMP22
Neurological

7

VNTRs repeat polymorphisms:

14-500 bp

10

Tay-Sachs is a __________ inheritance

Autosomal recessive

11

Example of lethal mutation

Infantile Tay-Sachs

12

B-Thalassemia is a _____________ inheritance

Autosomal recessive

13

B-Thalessemia specific genetic mutation

Different point mutations affect B-globin gene and result in a decrease in the production of B-globin

16

Hemophilia B specific genetic alteration:

An A to G transition alters the bind of a key transcription factor needed for expression

17

Frame-shift mutation

Insertion/Deletion of 1-2 bp. Everything past the insertion/deletion is read in the wrong frame

18

SNPs

Single Nucleotide Polymorphisms

20

Conditional Mutations:

Depend on the environment for manifestation of the disease symptoms

21

Cystic Fibrosis is a ____________ inheritance

Autosomal recessive

23

Cystic fibrosis alters the ___________ gene and is a __________ disorder

CFTR
Lung

24

How does VNTR technique work in solving identity

Excluding people rather than recognizing people

25

Charcot-Marie-Tooth disease (CMT) results in:

Peripheral nervous system disease resulting in progressive atrophy of distal limb muscles

26

In a transition point mutation, a ______ is replaced by a ______

Purine, different purine
Or
Pyrimidine, different pyrimidine

30

B-thalassemia is alters the __________ gene and is a __________ disorder

B-globin
Blood

31

The number of repeats in a sequence can be used to creat a:

“Molecular fingerprint” of individuals

32

Nuerofibromatosis Type 1 (NF1) has a _______________ phenotype

Highly variable

34

Tay-Sachs is common among populations of:

Ashkenazi Jewish
Cajun
French Canadian

35

Most common inherited neurological disorder:

Charcot-Marie-Tooth disease

36

Point mutation:

Represent single base pair changes in the sequence of DNA

38

Huntington’s disease is the result of:

An expansion of a CAG triplet

40

Tay-Sachs is a deficiency:

Lysosomal storage disorder resulting from a deficiency of the lysosomal hexosaminidase A protein coded for by hexA gene

41

Large deletion can be a result of:

Aberrant recombination

42

Lack of hexosaminidase A leads to:

A build-up of GM2 ganglioside in neuronal lysosomes, causing neuron damage

44

Symptoms of Neurofibromatosis Type 1 (NF1)

Neurofibromas
Cafe-au-lait spots
Lisch nodules in the iris

45

The most common genetic mutation for cystic fibrosis:

Deletion of three nucleotides within the coding region (In-Frame mutation)

46

Example of conditional mutation

G6PD deficiency

47

In-frame mutation

Insertion/Deletion of 3 bp. Extra amino acids are inserted/deleted by remaining codons are read correctly

49

Mutations can be generated by:

Failure of the DNA to copy accurately
Internal/external influences of the DNA structure/nucleotides

50

Lethal mutations:

Cause the organism to die, often during development leading to miscarriage

52

Neurofibromatosis Type I (NF1) specific genetic mutation

Nonsense mutation that introduces a stop codon into the NF1 coding region. Shortened protein is unstable and rapidly degraded

54

Which gene is associated with Charcot-Marie-Tooth disease?

PMP22: encodes peripheral myelin protein

56

CFTR:

Cystic Fibrosis Transmembrane Conductance Regulator

57

Example of a large deletion mutation:

A-thalassemia

59

A-thalassemia alters the _____________ gene and is a ___________ disorder

A-globin genes
Blood

60

VNTRs stand for:

Variable Number Tandem Repeats (mini satellites)

61

CFTR function:

Chloride channel

64

Missense mutation:

Wrong amino acid

65

Tay-Sachs alters the gene _______ and is a ________ disorder

HexA (hexosaminidase A)
Neurological

66

Example of Loss-of-function mutation

NF-1, cystic fibrosis

69

The most common variant of Tay-Sachs is caused by:

A 4 base insertion in the hexA gene (frameshift) resulting in a premature stop codon (nonsense)

70

Hemophilia B alters the gene ________ and is a __________ disorder

Factor IX
Blood clotting

71

Gain-of-function mutation:

Increased protein activity, novel protein activity, or protein expressed in a novel location

72

Neurofibromatosis Type I (NF1) is ___________ inheritance

Autosomal dominant

74

Neurofibromatosis type 1 alters __________ gene and is a ____________ disorder

NF1 (neurofibromin)
Neurological (neurofibromas, learning disabilities)

75

Phenotype represents:

The observable character of the cell or organism

76

Sickle-cell disease alters _________ gene and is a ________ disorder

B-globin
Blood

78

STRPs are repeats of about

205 bp

80

Epigenetic changes are:

Alterations in phenotype without a true alteration in genotype

83

Loss-of-function mutation:

Function of the GENE is lost, either partially or completely

84

In a transversion point mutation, a ________ is replaced by a _____________

Purine, pyrimidine
Or
Pyrimidine, purine

85

Methylation (is/is not) a form of mutation

Is not

87

CODIS:

(Combined DNA Index System) is a panel of 15 VNTR loci used by the FBI

88

Large insertion disease:

Charcot-Marie-Tooth disease

92

Most severe form of Tay-Sachs

Infantile

93

Influences on phenotype

Genotype and environment

96

Polymorphism versus Mutations

Polymorphism: common variants in DNA sequence in a population

Mutations: changes in the DNA sequence of an individual

98

Purine:

Adenine (A) and guanine (G)

99

Silent mutation:

Base change that doesn’t change the amino acid

101

Sickle cell disease specific mutation

Missense mutation A to T transversion that changes the amino acid

106

Point mutations in B-thalassemia can affect:

Transcription levels of the gene (promoter region mutation)
Splicing of the gene
Amino acid sequence of the the coding region (missense, nonsense)
Stability of protein (nonsense)

108

Two types of point mutation:

Transitions and Transversions

109

Pyrimidine=

Thymidine (T) and Cytosine (C)

110

CNVs have repeat polymorphisms:

Greater than 1000 bp, up to 2 million bp

113

Consequences of point mutations:

Missense, nonsense, silent

116

Nonsense mutation

New stop codon

117

Sickle cell disease is a __________ inheritance

Autosomal recessive

121

An allele is a:

Variant form of a gene that was created by the occurrence of a mutation in the DNA sequence

122

Hemophilia B is a ____________ type of inheritance

X-linked recessive

125

Changes in genotype do or do not always result in changes in phenotype

Do not

131

Genotype represents:

The genetic constitution of an organism. It is the summation of all of the DNA within the cell or organism

132

Mutations are:

Changes to the nucleotides within the DNA

134

STRPs stands for:

Short tandem repeat polymorphisms (microsatellites)

143

CNVs stand for:

Copy Number Variations

144

Much of the inter-individual variation seen between people is attributed to:

Polymorphism