Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Block 1 > Genetics 2 > Flashcards

Genetics 2 Flashcards

1
Q

structural variants: hb S vs Hammersmith vs Hyde/M vs Kempsey vs E

A

beta chain glu6val aa sub –> sickle cell anemia –> hemolysis vs beta chain phe42ser –> hemolysis vs beta chain his92tyr –> nonfxnal metHb reductase –> metHb can’t be Hb –> can’t carry O2 vs Hb has high affinity to O2 –> less O2 in tissue, erythrocytosis, GAIN OF FXN vs abnl RNA splicing –> MILD THAL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

causes of alpha thal vs beta thal. which is more severe?

A

unequal crossing over –> single, triple gene complex vs imbalance in globin synthesis, point mutation > sm deletion. alpha thal more severe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

locus control region (LCR). what happens if they’re deleted?

A

controls beta globin gene expression. complex beta-thal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Hereditary persistence of fetal hemoglobin (HPFH)

A

prevent perinatal switch from gamma to beta globin synthesis, clinically benign; caused by mutation in gamma gene promoter or beta gene cluster –> ectopic expression of HbF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

monogenic traits/single gene dzs vs polygenic traits vs multifactorial inheritance vs chromosomal dzss

A

controlled by 1 gene vs 2 genes vs 2+ genes + environ vs mono/trisomy, translocations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

multifactorial inheritance: qual traits vs quant traits

A

traits = absent or present vs continuous traits measured in a range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

qual traits: relative risk ratio vs familial aggregation

A

= 1 –> no genetic impact, > 1 –> possible genetic impact vs clustering of certain traits, behaviors, disorders within a family

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

quant traits: correlation

A

r > 0 –> pos correlation –> genetics may play a role, = 0 –> no correlation –> genetics don’t play a role

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

concordance vs discordance vs heritability

A

when both twins have same dz; greater concordance = b/w MZ than DZ means strong genetic component involved vs when one twin has disease and the other does not vs variance caused by genetic factors of a specific trait in a pop; H2=1 –> strong genetic component, H2=0 –> no genetic component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

risk factors of schizo

A

genetic predisposition and environmental stressor, closer genetic relative –> higher risk; DIGEORGE = INVOLVED IN 2% OF SCHIZO CASES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

histone acetylation vs methylation

A

Histone acetyltransferases (HAT) add histones –> more euchromatin –> inc transcription, Histone deacetylases (HDAC) removes histones –> dec transcription; HDAC inhibitors increase transcription vs * Added to lysine or arginine residues –> different impacts on transcription; Writers add methyl groups (Histone methyltransferase), Erasers remove methyl groups (Histone demethyltransferase), Readers recruit writers and readers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

DNA methylation

A

by DNA methyltransferases; DNMT1 maintains methylation patterns, DNMT3A & B are for de novo methylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

ex of histone tail mods

A

acetylation, methylation, ubiquitination, phosphorylation, deamination; each mod gives diff conseq –> histone code

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

histone variants

A

Proteins that substitute for core canonical histones in nucleosomes of euks –> specific structural and functional features

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

CCR5 gene

A

Encodes cytokine receptor found on cell surface of CD4 Th cells; Receptor = cofactor for HIV binding –> entry into T cells; Deletion in gene (ΔCCR5) –> frameshift mutation –> nonfunctional receptor –> immune to HIV; Only for homozygous individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

4 ca classes: carcinomas vs sarcomas vs hematopoietic vs neuroectodermal

A

from epith tissue vs from mesen tissue vs from bone marrow, lymphatic system, peripheral blood vs C/PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

driver vs passenger gene mutations

A

Directly initiate development and progression of cancer; if in critical driver genes –> initiate oncogenesis vs random mutations that are not recurrent in a particular tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

chromosomal vs regional/subchromosomal mutation

A

mutation in intact chrm –> number of chrm changes vs Affect structure or regional organization of a chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how can you get gene mutations?

A

from mutagens (chemical, rad, viral) or error in DNA repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

3 major mechanisms for ssDNA repair: nucleotide excision repair vs base excision repair vs mismatch repair

A

LOCAL distortions of DNA helix –> nuclear endonucleases recognize and cleave abnl chain on 3’ & 5’ side of distorted region –> short oligonucleotide w/ distortion = released –> gap in DNA –> DNA pol and ligase fill in gap (ex: repair pyrimidine dimers) vs DNA lesions involving base alterations or spontaneous loss –> specific glycosylases cleave base –> apurinic/pyrimidinic site (AP site) –> AP endonucleases recognize missing base and make endonucleolytic cut on 5’ side –> deoxyribose phosphate lyase removes the sugar/phosphate hanging out –> DNA pol and ligase complete repair vs non-dmged mismatched bases after DNA pol proofreading error/slip –> in euks: find nicks in strands and how Mut proteins interact w/ PCNA –> endonuclease cuts into strand –> exonuclease removes mismatched bases –> DNA pol and ligase complete repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

ca genomics vs exome seq vs gene expression microarrays

A

study of DNA-associated changes that accompany cancer; look for biomarkers representing abnormalities in epi/genome of cell prolif vs look for specific mutations in DNA coding regions vs look for gene expression signatures of a specific tumor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

pharmacogenetics vs pharmcogenomics

A

study individual vs mult genes simult that cause efficacy or toxicity to drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

xenobx

A

chemical not naturally produced or expected to be present in org –> body tries to get rid of it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

results of drug metab in liver

A

inactive –> active
inactive –> toxic form
active –> inactive
active = excreted
active = toxic b/c can’t convert and accumulate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

pathways for acetominophen

A

glucuronide or sulfate (95%), glutathione (5%), accumulate –> hepatotox

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

types of SADRs

A

lifethreatening, death, congenital, hosp, incapacitiy/disability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

cyp2d6 vs cyp3a4/5 account for % cyp in liver?

A

2%, works on 25% drugs rxed vs 40%

28
Q

phenocopying. example?

A

taking an inhibitory drug + CYP2D6 substrate –> alters apparent phenotype of the patient (make nml metab look like poor metab). tamoxifen + paxil –> CYP2D6 can’t convert tamoxifen to endoxifen

29
Q

PT/INR

A

prothrombin time/int’l normalized ratio; measure time for blood to clot; phenotypic test; used for warfarin dosing

30
Q

deletion vs insertion of homozygotes for ACE drugs

A

more vs less responsive to ACE drugs

31
Q

ACE inhibitors

A

prevent conversion of angiotensin I to II –> narrow blood vessels –> release hormones to raise bp

32
Q

G6P deficiency (G6PD)

A

inc sensitivity to antimalarial primaquine –> hemolytic anemia

33
Q

mutation in butrylcholinesterase

A

dec enzyme activity –> can’t metab succinylcholine –> malignant hyperthermia –> ventilation

34
Q

6-MP on TMPT activity in RBC

A

Low TPMT activity in RBCs –> high active agent TGN via HGPRT –> severe tox
High TPMT activity in RBCs –> reduced 6-MP

35
Q

irinotecan has tandem rpts TATATA

A

6 rpts = nml
7+ rpts –> low expression –> low removal of active cmpd –> diarrhea, leukopenia

36
Q

5-fluorouracil = prodrug to FdUMP, FdUTP, FUTP:

A

FdUMP inhibits thymiddylate synthase by ternary complex –> toxic, FdUTP and FUTP incorporate into D/RNA –> toxic

37
Q

5-fluorouracil can be inactivated in liver by

A

dihydropyrimidine dehydrogenase (DPD); but if DPD deficiency –> high 5-FU –> toxic –> fatal

38
Q

most common DPD variant

A

G>A transition in exon 14 in Caucasians

39
Q

how to handle PKU? what are PKU sxs?

A

defect in PAH or BH4 –> Avoid phe, add tyr, add BH4. mental retardation, small head, stunted growth, eczema, sz, fair skin

40
Q

ex of lifestyle adjustments

A

Porphyria  min sun and alc
Hereditary pancreatitis  avoid smoking and alc
Hereditary ca  freq ca screen
Hemochromatosis  blood letting

41
Q

ex of diet restrictions

A

Maple syrup urine dz/branched chain ketoaciduria) –> remove leu, ile, val from diet
Glutaric acidemia –> low lys/high arg
Celiac dz –> avoid gluten
Galactosemia (NOT lac intol) = mutations in 3 enzymes of Leloir pathway –> avoid gal
PKU: Defect in PAH or BH4 –> Avoid phe, add tyr, add BH4

42
Q

ex of replacement therapy

A

Congenital adrenal hyperplasia (CAH)  give cortisone
Congenital hypothyroid  give thyroxine
Homocystinuria  give vit B6
Rickets  give vit D
Hemophilia  give clotting factor 8 for A, 9 for B
oDM  insulin

43
Q

ex of pharmaceutical management

A

Wilson’s dz  penicillamaine, trientine
Factor V Leiden  anticoag like warfarin
Crigler-Najjar syndrome Type II and Gilbert syndrome  phenobarbital

44
Q

in vivo vs ex vivo and its main challenge

A

direct delivery vs pt cells extracted –> cells = modified w/ virus –> viral DNA incorporated into genome –> cells producing good protein reintroduced into pt (one problem: how do you know if reintro cells populate body?)

45
Q

barriers of in vivo vs ex vivo

A

How to target correct tissue?
How to avoid immune response?
How to know when change will take effect?
vs
What if DNA did not pick up new genome?
How to maintain sterility throughout process?
What happens if first time doesn’t work?
What if cells can’t grow outside of body?
Also includes in vivo barriers

46
Q

spinal muscular atrophy

A

mutation in SMN1 gene + silent mutation in SMN2 gene –> destroy splicing enhancer and create splicing silencer –> skip exon 7 –> malfunctional protein

47
Q

Hereditary transerythrin-mediated amyloidosis (hATTR)

A

misfolding of transerythrin in liver –> amyloid plaques –> dysfxn; onpattro has ds siRNA to reduce TTR prod –> no dysfxn

48
Q

genetic (diagnostic) testing vs genetic screening

A

analyzing D/RNA, protein, analytes for dz-causing genes vs determine which individuals have higher risk factor for dz; NOT used to make dx but can guide you which diag tests to take; NEED TO BE HIGHLY SENSITIVE AND SPECIFIC

49
Q

sensitivity vs specificity vs genetic screen

A

measures affected ppl –> high rate of true pos/low rate of false neg vs measures unaffected ppl –> high rate of true neg, low rate of false pos

50
Q

CF

A

mutation in CFTR gene and most delta508; viscous mucus in lungs; auto rec

51
Q

criteria for heterozygote test

A

cheap and dependable; no false pos/neg; genetic counseling = avail; accepted and voluntary participation of pop

52
Q

Tay Sachs dz

A

mutation in HEXA gene; 1:30 carriers in Ashkenazi Jewish, declined 90%; destroys nerve cells in brain and spinal cord

53
Q

indications for genetic counseling

A

previous child w/ birth defect, consanguinity, teratogen exposure, high risk pregnancy, hereditary condition, new dx of genetic dz

54
Q

VUS/variant of unknown significance

A

effect of the specific genetic alteration is not known; insufficient genetic data

55
Q

thalassemia vs structural variants

A

dec abundance in globin chains –> dec globin protein vs mutation that causes abnl aa seq of globins

56
Q

hemolytic anemia vs altered O2 transport

A

d/t hgb tetramer = unstable vs inc/dec O2 affinity or formation of metHb

57
Q

how is a zygote totipotent?

A

all its DNA = methylated; becomes pluri when some = unmethylated

58
Q

genomic imprinting

A

epigenetic phenomenon causing genes to be expressed in parent of origin manner

59
Q

allele freq vs genetic equil vs gene pool

A

% of allele in a pop vs concept that all allele freq = stable from generation to generation vs complete collection of all alleles in a pop

60
Q

selection

A

mate for cont advantageous traits –> decline deleterious traits

61
Q

HW asmptns

A

random mating in a large pop, no selection or migration, no mutation, allelic freq = constant

62
Q

carcinogenesis

A

when nml cells become ca cells: nml –> prolif –> local invasion –> LN invasion –> distant metast

63
Q

genes causing lynch syndrome/HNCC

A

mismatch repair genes: MSH 2/6, MLH 1, PMS2 –> microsatellite instability

64
Q

imatinib

A

inhibits tyr kinase BCR-ABL1 protein –> tx CML (chrm 9-22 translocation)

65
Q

nat’l newborn screens

A

sickle cell anemia, congenital hypothyroid, PKU, galactosemia

Block 1 (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions