Brainscape's Knowledge GenomeTM

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


See full index

Pathology Exam 1 > Lecture 12 - Genetic Diseases > Flashcards

Lecture 12 - Genetic Diseases Flashcards

1
Q

What are the basic units of the body?

A

Cells

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

Where are chromosomes located in the cell?

A

in the nucleus

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

genes reside on what?

A

chromosomes

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

Genes carry the code for _____

A

proteins

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

the genetic code consists of 4 letters, what are the letters and names?

A

Adenine
Cytosine
Guanine
Thymine

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

the nucleus of each human cell contains strands of DNA known as __________ and they are arranged in _____

A

chromosomes and they are arranged in pairs

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

There are 22 pairs of ____ chromosomes and one pair of ____ chromosomes

A

22 pairs of autosomal chromosomes and one pair of sex chromosome

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

Each chromosome consists of a series of genes, and the Human Genome Project has identified about how many protein-coding genes?

A

19,000

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

Each gene contains the genetic information required to produce a ____.

A

protein

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

Each ____ is made specifically to perform a necessary body function

A

protein

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

Mutations of a certain gene locus may affect one or both of the ______ in a pair

A

chromosomes

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

What does it mean to be heterozygous for a disorder?

A

when one chromosome in the pair is affected

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

what does it mean to be homozygous for a disorder?

A

if both chromosomes at a given gene locus are affected

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

what is the definition of mutation>

A

permanent change in the DNA

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

when a mutation affects germ cells, it can be transmitted to _____

A

progeny

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

when a mutation affects a somatic cell it can result in what two things?

A

tumors or developmental malformations

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

What are the names of the three types of mutations?

A

point (missence) mutation
frameshift mutation
trinucleotide repeat mutation

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

what is the definitions of a point (missence) mutation and what is an example?

A

single nucleotide base substituted

Examp: sickle cell anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the definition of a frameshift mutation?

A

insertion or deletion of one or two base pairs, altering reading frame of the DNA strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the definition and what is an example of trinucleotide repeat mutation?

A

amplification of sequence of 3 nucleotides

Examp: Fragile X syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is a single nucleotide polymorphism?

A

variation in just one nucleotide (for example, A or T) at a single site on the DNA molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

over 6 million polymorphisms have been identified, but most are within which three regions?

A

exons
introns
and intergenic regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

polymorphisms may be markers for multigenic complex diseases, such as what?

A

diabetes or hypertension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are different numbers of large contiguous stretches of DNA, from 1,000 to million of base pairs?

A

copy number variations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

in copy number variations how many involve gene-coding sequences, and this may account for variation in what?

A

half involve gene-coding sequences, and it may account for much PHENOTYPIC variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what refers to modulation of gene expression without altered DNA sequence?

A

epigenetic changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

epigenetic changes are important in what?

A

development as well as normal homeostasis

28
Q

with epigenetic changes, methylation of promoter regions makes them inaccessible to RNA polymerase, thus reducing what?

A

protein synthesis

29
Q

what is the definition of alterations in non-coding RNAs?

A

micro-RNAs (miRNA’s) inhibit translation of their target messenger RNAs into their corresponding proteins

30
Q

mendelian disorders are diseases caused by what?

A

single gene defects

31
Q

what is the definition of autosomal dominant disorders?

A

implies that the altered gene locus is on an autosome and disease will be evident clinically when only one of the chromosomes i the pair exhibit a mutation at the affected gene locus

32
Q

the majority of autosomal dominant disorders create which type of changes?

A

outward physical changes

33
Q

when is the mutant gene present in autosomal dominant disorders and what is an example?

A

it is present from birth

example: Huntington disease

34
Q

(T/F)

  1. Many Autosomal dominant disorders are exhibited at birth
  2. In autosomal dominant disorders the mutant gene is present from birth.
A
  1. False - many autosomal dominant disorders exhibits a delayed age of onset
  2. True
35
Q

With autosomal dominant disorders, how many parents are usually affected?

A

one of he parents is usually affected

36
Q

(T/F) only females can have the disorder and transmit the mutant gene

A

False - both males and females can have he disorder and transmit the mutant gene

37
Q

what percent of the offspring will have the disease if only one parent is affected with autosomal dominant diseases?

A

half or 50% of the offspring will have the disease

38
Q

what is the definition of reduced or incomplete penetrance?

A

person has a mutant gene but does not express it phenotypically

39
Q

what is the definition of variable expressivity?

A

trait is seen phenotypically in the individuals having the mutant gene but is EXPRESSED DIFFERENTLY among individuals

40
Q

what is the definition of de novo mutation?

A

affected individuals may not have affected parents because their disease arose from a new mutation

41
Q

what is the definition of autosomal recessive disorders?

A

recessive implies that the trait is expressed only if both genes at a given locus are affected (homozygous individuals)

42
Q

what is the largest group of mendelian disorder?

A

autosomal recessive disorders

43
Q

with autosomal recessive disorders do the parents of the affected individual show the disease?

A

the parents of the affected individual usually do not show the disease

44
Q

offspring of heterozygous carrier parents have what chance of getting the disease

A

offspring of heterozygous carrier parents have a one in four chance of the disease

45
Q

offspring of heterozygous carrier parent have what chance of being a carrier?

A

one and two chance of being a carried

46
Q

if the mutant gene is rare, there is a strong probability that the affected child (proband) is the product of what kind of relationship?

A

consanguineous

this means - relating to or denoting people descended from the same ancestor.

47
Q

what are the basic concepts of autosomal recessive disorders?

A
  • two germline mutations (one from each parent)
  • equally transmitted by men and women
  • 25% of offspring; horizontal pattern in family
48
Q

what type of pattern is seen in families with autosomal recessive disorders?

A

horizontal pattern in family

49
Q

with autosomal recessive disorders - many of these disorders present with enzyme defects that produce what?

A

inborn error of metabolism

50
Q

in heterozygous individuals with autosomal recessive disorders, the disease is not clinically event but they may possess reduced amount of what?

A

the normal enzyme

carriers are heterozygous individuals (the disease is not evident clinically)

51
Q

in autosomal recessive disorders the age of onset is more frequently when?

A

in early life

52
Q

the expression of the defect tends to be more ____ and _____ _____ is common

A

tends to be more uniform and complete penetrance is common

53
Q

although new mutations do occur, they are usually not detected for what reasons?

A

since that individual would be a carrier without clinical manifestations

54
Q

almost all X-linked disorders are recessive or dominant?

A

recessive

55
Q

are males or females carried for X linked disorders?

A

females - because they are usually heterozygous for the gene because they have 2 X chromosomes

56
Q

who is affected by x linked recessive disorders?

A

homozygous females and males (who are automatically hemizygous because they have only 1 X chromosome) are affected

  • mutant genes are on the X (sex) chromosome
  • women must inherit 2 mutated copies to be affected
  • all men who inherit the mutation are affected (only one X chromosome)
57
Q

although it is rare, heterozygous females may demonstrate full expression due to what?

A

unfavorable lyonization

58
Q

what is lyonization?

A
  • 16 days after concpetion, all but one X chromosome is randomly inactivated in all of the cells within the zygote’’- Either the maternal or paternal X may be inactivated in each cell and that X remains inactivated in the progeny of the cell
59
Q

with lyonization, the cells in normal females represent a mixture of two cell types, what are they?

A

those with active paternal X and those with active maternal X
- in disorders of the X chromosome, typically females are an even mixture of normal and abnormal chromosomes

60
Q

what is unfavorable lyonization?

A

inactivation of an abnormally high percentage of normal X chromosomes, leading to clinical evidence of the disease in a heterozygote

61
Q

what is affected in x linked dominant and what is an example?

A

heterozygous
homozygous
hemizygous are all affected

Example: Oral-Facial-Digital syndrome (OFD) type I

62
Q

What are 2 diseases that are caused by mutations in structural proteins?

A

Marfan syndrome

Ehlers-Danlos Syndrome

63
Q

what is Marfan syndrome?

A

-Autosomal dominant disorder of connective tissue due to mutation of the FBN1 gene, resulting in abnormal FIBRILLIN, a glycoprotein necessary for normal elastic fiber production

64
Q

what is the prevalence of Marfan syndrome?

A

1 in 5,000

65
Q

what are some clinical manifestations of Marfan syndrome?

A

tall, thin body habitus with abnormally long legs, arms and fingers (arachnodactyly - spider fingers)
-Dislocation of lens of the eye
-Aortic aneurysm and dissection leading to heart failure and aortic rupture
Examples: Abraham lincoln? sudden death of basketabll players?

Pathology Exam 1 (6 decks)

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