Lecture 2 Flashcards
Allele
The DNA sequence(s) at a locus of one of the two homologous chromosome
Ex; T allele, C allele
(together make T/C genotype)
Genotype
The combination of alleles at the same locus of the homologous chromosomes in a genome/cell
EX: T/C genotype
Homozygote
When an individual has a pair of identical alleles at the locus, the genotype is homozygous
Heterozygote
Two different alleles at the same locus, the genotype is heterozygous
Hemizygous/Hemizygote
One allele presents, while another allele is missing
Hemizygous genotype is also heterozygous
not common
Mendel’s Law
Each of the parents passes a randomly selected allele (one of the two homologous chromosomes) to the offspring (law of segregation)
Single Nucleotide Polymorphism (SNP)
A single nucleotide is changed to another
The most common DNA sequence variation account for >90% of all genetic variations
Most PGx polymorphisms are _
SNPs
cSNP
SNP in the coding region
Non-synonymous SNP
Changing amino acid in the protien
Missense SNP
Amino acid substitution (could lead to either gain or loss of function for the protein depending on what amino acid it changes to)
Nonsense SNP
amino acid changes to a stop codon **normally lead to a loss-of-function)
Synonymous SNP
Does not change amino acids, usually does not change gene/protein function
CNV
Copy number variation
A DNA region (many contain a part or even one or more entire genes) has 0-n copies in a population
Structural variation
Making each chromosome longer or shorter
more copies someone has, more efficient they are at metabolizing drugs
Indel
Insertion/deletion
-Nucleotide(s) present or absent from a locus: 0 or 1 copy
Can be 1 to N nucleotides
Single nucleotide indel is a specific form of SNP
Large ones are actually CNVs
Example: CYP3A5*7
Insertion and deletion other than _ _______ often causes ____ of the open reading frame leading to truncated protein for degradation
3 nucleotides
Frameshift
*D means
Loss of function
*17 means
Gain of function
