1-15-25

Question 1

what is an allele?

Answer 1

the DNA sequence at a locus of one of the two homologous chromosome

Question 2

what is a genotype?

Answer 2

the combination of alleles at the same locus of the homologous chromosomes in a genome/cell

Question 3

what is a homozygote?

Answer 3

pair of identical alleles at the locus

Question 4

what is heterozygote?

Answer 4

two different alleles at the same locus

Question 5

what is hemizygous/hemiygote?

Answer 5

one allele present while another allele is missing
genotype is still heterozygous

Question 6

what is mendel’s law?

Answer 6

each of the parents passes a randomly selected allele to the offspring via the law of segregation

Question 7

what is single nucleotide polymorphism (SNP)?

Answer 7

when a single nucleotide is changed to another
most common variation and accounts for 90% of all differences
most PGx polymorphisms

Question 8

what are the types of SNPs?

Answer 8

non-synonymous SNP
synonymous SNP
noncoding region SNPs

Question 9

what is non-synonymous SNP?

Answer 9

changing amino acid in the protein
either missense or nonsense

Question 10

what is missense SNP?

Answer 10

amino acid substitution
could lead to either gain or loss of function for the protein depending on what amino acid it changes to

Question 11

what is a nonsense SNP?

Answer 11

amino acid changes to a stop codon leading to loss of function

Question 12

what is synonymous SNP?

Answer 12

does not change amino acids and usually does not change gene/protein function
also referred to as silent SNP

Question 13

what is non-coding region SNP?

Answer 13

itronic SNP, SNP in the gene flanking regions and intergenic regions, or SNPs in the UTR region

Question 14

what is a copy number variation (CNV)?

Answer 14

when a DNA region has 0-n copies in a population
structural variation
makes each chromosome longer or shorter

Question 15

what is indel polymorphism?

Answer 15

insertion/deletion
causes frameshift of the open reading frame leading to truncate protein for degradation

Question 16

what is a truncate protein?

Answer 16

loss-of-function
Nonsense mutation results in a similar consequence

Question 17

what are the changes associated with CNV?

Answer 17

7 copies of CYP in genome in transcription
70K drug molecules metabolize
GAIN-OF-FUNCTION

Question 18

what are the changes associated with repetitive DNA variation?

Answer 18

makes 50 copies of mRNA in transcription
5K drug molecules metabolized
LOSS-OF-FUNCTION

Question 19

what are the changes associated with missense?

Answer 19

results in either GoF or LoF
hyperactivation of protein that metabolizes 15K drug molecules

Question 20

what is the changes associated with nonsense?

Answer 20

LoF
truncated non-functional protein
non-function protein all degraded thus 0 metabolized drug molecules

Question 21

what is the rs number?

Answer 21

reference SNP

Question 22

what encompasses a gene name?

Answer 22

the super family (CYP), family (2), subfamily (C), and isoform (19)

Question 23

what does 1A mean in the CYP2C19* protein?

Answer 23

no change
normal function

Question 24

what does 2D mean in the CYP2C19* protein?

Answer 24

splicing defect
LoF

Question 25

what does 3A mean in the CYP2C19* protein?

Answer 25

nonsense (stop codon)
LoF

Question 26

what does 17 mean in the CYP2C19* protein?

Answer 26

missense (point mutation)
GoF