App. B Genetic testing Flashcards
What are the three observed types of hereditary diseases
- A single gene mutation causes the hereditary disease
- A mutation in any one of multiple genes causes the
hereditary disease - The combination of genes plus the influence of outside
factors causes the onset of the hereditary disease
What are the three classifications of hereditary disease? Know the key points of each
- Mendelian Conditions
- Chromosomal Conditions
- Multifactorial Conditions
Molecular analysis tests ____ or ________ and is useful when there is suspicion of a specific ____________ condition
DNA/ RNA/ Mendelian
6 types of genetic testing
- Presymtomatic genetic testing
- Carrier genetic testing
- Newborn genetic screening
- Prenatal genetic testing
- Preimplantation genetic screening
- Direct-to-consumer genetic testing
How many repeats does a normal HD gene contain? What are the triplet that is repeated
- contains up to 34 CAG repeats that are consecutive
- Repeats encode a string of glutamine amino acids in the huntingtin protein
- of more than 34 CAG repeats then it will become unstable
What type of testing determines if a person is a heterozygous carrier for a recessive disease? If one partner is determined to not be a genetic carrier does the other partner need to be tested?
Carrier genetic testing
* The other partner does NOT need to be tested.
Is the newborn genetic screening mandated in all 50 US States?
YES
What is the main disease screened for using the Guthrie test?
Phenylketonuria (PKU)
What is the Guthrie test also known by
as known as heel stick or PKU
Prenatal genetic testing can look for which 3 abnormalities?
Inherited diseases, chromosomal abnormalities, and skeletal or developmental abnormalities
Fetal cell sorting is done by and can identify which diseases?
- Cystic fibrosis
- Spinal muscular atrophy
What is genetic counseling?
- integral part of medical genetics and is provided by specially trained genetic counselors
- aim to provide comprehensive, understandable medical information about a current condition or recurrence risk of a condition
What analysis does the probability estimation methodology use?
Bayesian analysis determines the probability of a
certain genotype occurring in a certain family member
- Uses known or inferred genotype information and prior information from offspring produced by set of parents
What is prior, conditional, and joint probability?
- prior probability of a genotype is determined; this is the likelihood that the hypothesis that an individual has a certain genotype is true
- conditional probability is calculated using
information such as traits of other offspring of the same parents as the individual of interest - joint probability is calculated by multiplying the prior probability by the conditional probability
Mendelian Conditions
- mutation of a single gene
- may be inherited from one or both parents carrying he mutation or may be the result of a new mutation
- Six patterns of inheritance
- Autosomal, Sex linked, Mitochondrial
- Dominant or Recessive
Multifactorial conditions
- influenced by multiple genes along with environmental factors
- Diabetes is an example
- Inherited genetic variation may play a role in making some
individuals more likely to develop the condition than others - This increased likelihood is referred to as an “inherited
susceptibility,” which may vary between populations - This variation is often due to differing mutant allele
frequencies in different populations
Presymtomatic genetic testing
determines whether or not a person carries a mutation that will cause future disease; few diseases can be tested this way
Carrier genetic testing
is more common; it determines if a person is a heterozygous carrier for a recessive disease
Newborn genetic screening
mandated in all 50 US states, tests newborns for three dozen or more treatable, rare genetic diseases
Prenatal genetic testing
identifies inherited diseases, chromosome abnormalities, and skeletal or developmental abnormalities
Preimplantation genetic screening
for specific and limited circumstances, tests for hereditary diseases in fertilized embryos produced by in vitro fertilization
Direct-to-consumer genetic testing
offered by for-profit companies, either duplicates medically available genetic carrier testing or provides information about
inheritance of genetic markers associated with certain hereditary conditions
