genetics

Question 1

pharmacogenomics

Answer 1

the study of how inherited genetic differences in humans influence individual responses to drugs

Question 2

polymorphism

Answer 2

genes that have more than one normal allele at the same locus

Question 3

genotype/phenotype

Answer 3

genetic constitution/expression of genotype

Question 4

mitosis

Answer 4

2n-2n (diploid)

Question 5

meiosis

Answer 5

2n-n (haploid)

Question 6

dominant traits

Answer 6

allele whose effects are observable in either homozygote or heterozygote state

Question 7

recessive trait

Answer 7

requires homozygote condition of genes to be present

Question 8

homozygote gene

Answer 8

required for recessive allele to be expressed. both alleles are identical

Question 9

heterozygote

Answer 9

different allele at each locus of gene. One allele dominant over the other.

Question 10

hemizygote

Answer 10

a diploid individual with only one allele at a given locus or gene instead of typical two. The men are physiologically hemizygous for the genes located on X chromosome

Question 11

penetrance

Answer 11

percentage of individuals with a specific genotype who also exhibit the expected phenotype

Question 12

karyotype

Answer 12

identification of individual chromosomes prepared by slides during metaphase

Question 13

aneuploid cell

Answer 13

a somatic cell that does not contain a multiple of 23 chromosomes

Question 14

cri-du-chat syndrome

Answer 14

partial deletion of p arm of chromosome 5

Question 15

turners syndrome

Answer 15

45, XO 
deletion of a sex chromosome
phenotypical females
sterile
short stature
webbed neck

Question 16

sex chromosome addition

Answer 16

klinefelters syndrome
47, XXY
phenotypical male
sterile
no body hair
gyno
tall

Question 17

trisomy 21/ downs syndrome

Answer 17

47xy+21
mental retardation short
hypotonia
simian crease(line)

Question 18

familial hypercholesterolemia

Answer 18

chromosome 19
most common mendelian disorders
lack of ldl surface receptor
elevated plasma cholesterol

Question 19

heterozygote plasma cholesterol in familial hypercholesterolemia

Answer 19

2-3 fold higher than normal

300-400 mg/dl

Question 20

homozygote plasma cholesterol in familial hypercholesterolemia

Answer 20

5 times higher than normal

600-1200 mg/dl

Question 21

autosomal recessive genes

Answer 21

inborn errors of metabolism

Question 22

PKU-phenylketonuria

Answer 22

chromosome 12
accumulation of phenylalanine-cns damage
treatment-diet low in phenylalanine
gene therapy candidate

Question 23

cystic fibrosis

Answer 23

chromosome 7
exocrine disorder
most lethal single autosomal recessive defect
defect in cftr(cystic fibrosis transmembrane conductance regulator)
gene therapy candidate

Question 24

x linked defects

Answer 24

hemophilia, color blindness, fragile x syndrome, muscular dystrophy

Question 25

factors related to developmental defects arise during what period

Answer 25

embryonic period

2-8 weeks after conception

Question 26

TORCH

Answer 26

toxoplasmosis, other, rubella, cytomegalovirus, herpes

Question 27

thalidomide

Answer 27

tranquilizer
banned worldwide after 12000 babies born with malformations
reduced tnf alpha- a cytokine
inflammatory response reduced and blood vessel growth arrested

Question 28

fetal alcohol syndrome signs

Answer 28

craniofacial- small head, chin and upper lip
growth- small, 2 sd below mean
cns abnormalities- microencephaly, hypotonia, retardation

Question 29

what reduces incidence of ntd by 50-70%

Answer 29

folic acid

Question 30

cell free fetal dna testing

Answer 30

tests mothers blood for babys dan

can detect several chromosomal defects 98% of time

Question 31

maternal blood sample/ quad screen test

Answer 31

alpha fetal protein (low=downs)(high=ntd)
unconjugated estriol (low=downs)
hcg(high=downs)
inhibin A (high=downs)

Question 32

can detect 11-35% chromosomal abnormalities

Answer 32

level 2 ultrasound

Question 33

amniocentesis

Answer 33

sampling amniotic fluid

15-18th week of pregnancy

Question 34

what does amniocentesis test show?

Answer 34

cytogenetic disorders
x linked disorders
ntd
inborn errors of metabolism

Question 35

only in 1st trimester(10th week)
can detect downs
can’t detect ntd

Answer 35

chorionic villi sampling (cvs)