Brainscape's Knowledge GenomeTM

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


See full index

Nature and Nurture of Mental Illness > Chapter 9: Identifying Genes > Flashcards

Chapter 9: Identifying Genes Flashcards

1
Q

What are three types of DNA mutations? (3)

A
  1. Substitution. 2. Insertion/Deletion (Indels). 3. Expanded Triplet Repeats.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are indels?

A

When an base pair is added or deleted.

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

What is a frameshift?

A

When an indel is less than 3, which causes an entire shift in the reading frame that may lead to an entirely new translation.

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

What is an expanded triplet repeat?

A

When genes feature repeat sequences (of variable numbers).

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

What is an example disease caused by expanded triplet repeats? What gene is involved?

A

Fragile X syndrome. FMR1 is repeated.

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

Are polymorphisms considered mutations?

A

No.

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

What is a single nucleotide polymorphism (SNP)?

A

A single base pair that varies in at least 1% of the population.

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

Where are the two regions where SNPs can be found?

A
  1. Coding region of the gene. 2. Non-coding region of the gene.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Within the coding region, what kind of SNPs can there be? (2)

A
  1. Synonymous. 2. Non-synonymous.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are synonymous SNPs?

A

When there is not a change in the amino acid created.

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

What are non-synonymous SNPs?

A

When there is a change in the amino acid created.

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

What kind of SNPs are we looking for?

A

Non-synonymous SNPs in the coding region.

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

What is a non-common DNA variant?

A

SNPs that occur rarely in the population (less than 5%).

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

What are copy number variants? Are they mutations?

A

Duplication or deletion of long stretches of DNA. Yes, because they are not inherited.

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

What is a linkage study?

A

Uses family members to examine whether specific DNA markers are linked to a trait.

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

What is a candidate gene association study?

A

Focuses on a single gene or SNP and how its alleles correlate with a trait or SNP in question.

17
Q

What is a Genome-wide association study (GWAS)?

A

Identifies SNPs that occur more frequently in people with a particular trait/disease than in people without.

18
Q

What is a SNP microarray?

A

A procedure that sequences only a part of the genome and amplifies it.

19
Q

What is a haplotype block?

A

A series of SNPs that are very highly correlated (i.e. seldom separated by recombination).

20
Q

What is a haploid genotype (haplotype)?

A

The DNA sequence on one chromosome.

21
Q

What are some limitations of GWAS? (4)

A
  1. Measurement. 2. Development (changes over time). 3. Clinical utility. 4. Doesn’t account for GxE interactions.
22
Q

What are polygenic scores?

A

A formula that aggregates the weighted small effects of many DNA variants associated with a quantitative trait using GWAS results.

23
Q

What do polygenic scores reflect?

A

A person’s genetic standing on a quantitative trait.

24
Q

How are polygenic scores generally obtained? (3)

A
  1. Obtaining a discovery sample. 2. Using that sample on a target sample. 3. Observing the unique polygenic score in each person in the population.
25
Q

What is first method to derive polygenic scores using GWAS?

A

Weighing each tiny SNP above the significance line (less than .05) by its effect size (B) and sum them together.

26
Q

What is the second method to derive polygenic scores using GWAS?

A

By weighing each SNP above a lower significance line (.05) by its effect sized and summing them together.

27
Q

What are three promising results of polygenic scores?

A
  1. More powerful predictive testing. 2. Capturing the full range of variation in a quantitative trait. 3. Thinking positively.
28
Q

Do polygenic scores map to self-report measures of neuroticism?

A

Yes.

29
Q

Are polygenic scores clinically useful yet? Why?

A

No, effect sizes are small and mental disorders are not completely heritable.

30
Q

How much of the phenotypic variance of ADHD can be explained using polygenic scores?

A

.7%.

31
Q

What are the three perils of polygenic scores?

A
  1. They can be manipulated (no standard p-value). 2. Not clinically useful. 3. No accounting for GxE interplay.
32
Q

How are polygenic scores calculated?

A

The sum of an individual’s number of risk alleles times their effect size.

33
Q

What is premutation for Fragile X syndrome?

A

Between 40 and 200 repeats of FMR1.

34
Q

What are quantitative trait loci (GTLs)?

A

Genes of various effect sizes in multiple-gene systems that contribute to quantitative (continuous) variation in a phenotype.

35
Q

What can linkage analyses be useful for?

A

For single gene disorders.

36
Q

What is a linkage analysis?

A

A technique that detects linkage between DNA markers and traits.

37
Q

What is linkage analysis used for?

A

To map genes to chromosomes.

Nature and Nurture of Mental Illness (7 decks)

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