ch 24 medical genetics

Question 1

personalized medicine

Answer 1

the use of information about a patient’s genotype and other clinical data in order to select a medication, therapy, or preventative measure that is specifically suited to that patient

Question 2

monozygotic (MZ) twins

Answer 2

twins that are genetically identical because they were formed from the same sperm and egg

Question 3

dizygotic (DZ) twins

Answer 3

(also known and fraternal twins) twins formed from separate pairs of sperm and egg cells

Question 4

concordance

Answer 4

in genetics, the degree to which a trait or disorder is inherited, determined by how many pairs of twins both exhibit it

Question 5

age of onset

Answer 5

the age at which symptoms of a disease first appear

Question 6

simple mendelian inheritance

Answer 6

an inheritance pattern involving simple, dominant/recessive relationships that produce observed ratios in the offspring that readily obey mendel’s laws

Question 7

haploinsufficiency

Answer 7

the phenomenon in which an individual has only a single functional copy of a gene and that single functional copy does not produce a normal phenotype; shows a dominant pattern of inheritance

Question 8

gain-of-function mutation

Answer 8

a mutation that changes a gene product so that it gains a new or abnormal function

Question 9

dominant-negative mutation

Answer 9

a mutation that produces an altered gene product that acts antagonistically to the normal gene product; shows a dominant pattern of inheritance

Question 10

locus heterogeneity

Answer 10

the phenomenon in which a particular type of disease or trait may be caused by mutations in two or more genes

Question 11

haplotype

Answer 11

the linkage of particular alleles or molecular markers on a single chromosome

Question 12

founder

Answer 12

with regard to genetic diseases, an individual who lived many generations ago and was the person in which the disease-causing allele originated

Question 13

linkage disequilibrium

Answer 13

phenomenon that exists when alleles and molecular markers are associated with each other at a frequency that is significantly higher than expected by random chance

Question 14

genome-wide association study (GWA or GWAS)

Answer 14

an examination of a genome-wide set of genetic variants among many different individuals to see if any variant is associated with a disease or other type of trait

Question 15

genetic testing

Answer 15

the use of testing methods to analyze an individual’s genes or gene products; in many cases, the goal is to determine if the individual carries a genetic abnormality

Question 16

genetic screening

Answer 16

the use of testing methods at the population level to determine if individuals are heterozygous carriers for or have a genetic disease

Question 17

amniocentesis

Answer 17

a method of obtaining cellular material from a fetus for the purpose of genetic testing

Question 18

chorionic villus sampling

Answer 18

a method for obtaining cellular material from a fetus for the purpose of genetic testing

Question 19

preimplantation genetic diagnosis (PGD)

Answer 19

a form of genetic testing in which an embryo obtained via in vitro fertilization is tested for genetic abnormalities prior to implantation within the uterus

Question 20

in vitro fertilization (IVF)

Answer 20

in the case of humans, the fertilization of an egg outside of a female’s body

Question 21

prion

Answer 21

an infectious particle that causes any of several types of neurodegenerative disease affecting humans or livestock; composed entirely of protein

Question 22

gene therapy

Answer 22

the introduction of cloned genes into somatic cells or the modification of existing genes in order to treat a disease

Question 23

liposome

Answer 23

a vesicle that is surrounded by a phospholipid bilayer

Question 24

ex vivo approach

Answer 24

in the case of gene therapy, refers to genetic manipulations that occur outside the body

Question 25

molecular profiling

Answer 25

methods that enable researchers to understand the molecular changes that occur in diseases, such as cancer

Question 26

pharmacogenetics

Answer 26

the study or clinical testing of genetic variation that causes differing responses to drugs