Lecture 11 Flashcards
(49 cards)
Why do pedigrees?
Punnett squares work well for organisms that have large numbers of offspring and controlled matings
human pedigrees
small families, uncontrolled matings often with heterozygotes, failure to truthfully identify parentage
Goals of pedigree analysis
- determine the mode of inheritance dominant, recessive, partial dominance, sex linked, autosomal, mitochondrial and maternal effect
- Determine the probability of an affected offspring for a given cross
If two affected people have an unaffected child will the pedigree be dominant or recessive?
dominant
If two unaffected people have an affected child, is it dominant or recessive?
recessive
If the affected person has an affected pattern is it dominant or recessive?
dominant
define pre-implantation genetic diagnosis
A test to check whether the fertilized egg has had the genetic disorder passed on
Define Guthrie Test
bacterial inhibition assay- test performed on newborn infants to detect PKU, an inborn error of amino acid metabolism
In recent years, what has happened with the Guthrie Test?
gradually being replaced in many areas with tandem mass spectrometry that can detect a wider variety of congenital diseases
What is hearing loss mostly due to?
congenital issues
How is the Guthrie test done?
blood from heal of the newborn is placed on filter paper then placed on agar plate with a strain of Bacillus subtilis
Define Diagnostic tests
invasive prenatal diagnosis
Define fetoscopy
involves visualization of the fetus by means of endoscope
What is fetoscopy being superseded by?
detailed ultrasonography
Define fluorescent in situ-hybridization
diagnostic tool combines conventional cytogenetics with molecular genetic technology- based on unique ability of a portion of ss DNA to anneal with its complementary target sequence
What is fluorescent in-situ hybridization useful for?
diagnosing various developmental disorders like Prader-Willi syndrome, Angelman syndrome and Down Syndrome
What do raised levels of alpha fetoprotein indicate?
open neural defect
What does low level of alpha fetoprotein indicate?
chromosomal aberrations (trisomy 21 causing down syndrome)
what effects may some pharmacogenetics have?
adverse effects may develop/toxic reactions due to genetically determined enzyme deficiencies
Define pharmacokinetics
movement of drug from the time of absorption into body- plasma concentration, tissue distribution, metabolism/detoxification in liver and then elimination from body (input to output)
Define pharmacodynamics
interaction of drugs with membrane receptors, enzymes, nucleic acids and exertion of their pharmacological effect
WHat is succinlycholine sensitivity?
short acting muscle relaxant used in general anesthesia- inactivated by plasma cholinestrase within 2-3 minutes
What happens in certain ethnic groups with succinlycholine?
the plasma cholinestrase is defective and succinylcholine is inactivation very slowly resulting in prolonged apnea
Mutation of which gene is responsible for succinlycholine sensitivity?
mutation of gene CHE1
