genetic screening Flashcards
genetic testin
1) changes in DNA
2) changes in chromosome
3) measure genetic changes, RNA analysis as an output of gene expression
4) biochemical analysis to measure protein output
—
tests available for more than 2000 genetic conditions
history of genetic testing
1 )1950s, counting chromosomes per cell
- trisomy 21
- monosomy x
2) 70s stain chromosome banding to analyzed chromosome structure
- structural arrangements
3) present, analyze cytogenetics, molecular genetics and genomics
- changes at levels of individual genes, or even SNPs
DCT genetic tests
1) direct to consumer
2) info about medical and non medical traits
3) ancestry, responses to medication, risk for developing conditions
4) cannot determine if you will get a disease
- should not be used alone to determine medical care
reasons for genetic testing
1) learn whether you have a genetic condition that runs in your family
2) learn about chances a child will have it
3) diagnose a condition if you or child has symptoms
4) understand and guide cancer prevention
5) do not do it if it is NOT relevant to you
categories of genetic tests
1) single gene testin
2) panel testing
3) large scale genetic or genomic testing
-
no single test can detect all genetic conditions
single gene testing
1) changes in one gene
- duchene muscular dystrophy
- sickle cell
panel testing
1) changes in many genes in one test
- breast cancer
- colon cancer
large scale genetic testing
1) exon sequencing external icon
- whole exome or just genes related to medical conditions
1) genome sequencing external icon
- all person’s DNA
for complex medical histories
types of genetic testing
1) cell free fetal DNA
- non invasive for fetus
- Down syndrome
2) newborn screening
- can identify genetic disorders to treat early in life
- congenital hypothyroidism
- must test for at least 21 disorders
3) diagnostic testing
- rule out a specific condition
- carrier testing
- cystic fibrosis
4) preimplantation genetic diagnosis
- human embryos prior to implantation as part of in vitro fertilization
5) prenatal diagnosis
- detect changes in fetus before birth
predictive and presymptomatic genetic testing
1) test gene mutations that appear after birth
2) predictive testing identify mutations that increase changes of developing disorders
- cancers
- BRCA1 => 65% of breast cancer
3) presymptomatic testing can determine disorder before signs and symptoms occur
- hemochromatosis
4) half of men and 1/3 women will develop cancer in their lifetime
5) certain genetic variants can make risk of cancer higher than average
pharmacogenomics
1) influence o genetic variation on drug response
- examine genetic makeup to determine what medicine and dosage is safest
2) 11 million SNPS in genomes in human
- response to certain drugs can be found in them
non diagnostic testing
1) forensic testing
- DNA sequencing to identify individual
2) paternity testing
- DNA markers to identify inheritance patterns
3) genealogical DNA test
- genetic genealogy to determine ancestry
4) research testing
- to find unknown genes and how they work
estonia
1) all residents offered genome wide genotyping
- personalized reports
2) healthier lifestyles and preventative drugs
united states
1) genetic information nondiscrimination act
- cannot deny health coverage on the basis of genetic predisposition to developing a disease in the future
2) bars employers from using individuals genetic information for job decisions
3) passed by Goerge W Bush and US senate
prenatal diagnosis
1) couples at high risk had to choose between taking risk, abortion, sterilization, adoption, or donor insemination
2) in 1960s, fetal medicine
- perform karyotype on unborn child
- detect abnormalities in fetus
3) 150,000 born in each year with birth defect in US
prenatal testing can involve
1) blood tests
2) imaging
3) chromosome analysis
4) other genetic testing to assess health of mother and baby
prenatal genetic screening and testing
1) Noninvasive
2) invasive
noninvasive
- maternal serum
- cell free fetal DNA
- ultrasonography
- fetal MRI
- fetal echocardiography
invasive
- amniocentesis (fluid, cells)
- chorionic villus sampling
-fetoscopy (Blood, liver, skin, visual)