Molecular diagnostics

Question 1

Single nucleotide polymorphisms

Answer 1

Most SNPs are variations are in the non coding regions but some affect gene expression

SNPs are identified by RT-PCR, with allele specific dyes binding to targets during the annealing phase

SNP direct hybridization - puts it on a hard surface computer, (only able to detect specific present alleles, unable to detect deletions and null allel)

Question 2

Melting based genotyping

Answer 2

mismatches and AT melt at lower temps than GC

Can find SNPs or indels in a small region of DNA, not just at a specific postion

Cannot specify the varient, and insensitive to deletions

Question 3

Indels

Answer 3

Insertions and deletions, large indels can be found by hybridization.

Microsatellites are small indels, repeating short segments of DNA, they are codominant markers, and follow mendelian genetics

Question 4

Phenotypic Effects and Frequency

Answer 4

The more common a varient is, the less it will have an impact on health

Additive and dominance components of allelic effects

Question 5

Linkage disequilibrium

Answer 5

present when alleles at neighboring loci are associated more frequently than would be expected on the basis of chance alone haplotype issues

Question 6

Cytochrome P450 polymorphisms

Answer 6

different people respond differently to drugs
Pharmacogenetics uses genetic information to predict responses to medication

CYP450 enzymes are phase 1 enzymes that are involved in metabolism and bioactivation of 3/4 of drugs and xenobiotics (they also have SNPs that can impact drug metabolism) *1 allele is the normal fuctional allele of CYP450

Question 7

SNP microarrays

Answer 7

Thousands of nucleic acid sequences are arranged in grids on glass or silicon. DNA or RNA probes are hybridized to the chip and a scanner detects the relative amounts of complementary binding.

Used to profile gene expression levels of thousands of genes simultaneously to study certain diseases and treatments. Can detect SNPs, CNV for genotyping clinical genetic testing, forensic analysis, cancer mutations, and genetic linkage analysis

Question 8

Trinucleotide Repeat diseases

Answer 8

Genetic anticipation (severity increases with age)