Brainscape's Knowledge GenomeTM

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


See full index

Speciality teaching > Genetics > Flashcards

Genetics Flashcards

1
Q

What is a somatic mutation?

A

Damage in single cell, then a second hit would happen, can develop metastatic potential. Not in gremlin tissue, cannot be passed on

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

What is gremlin mutation?

A

Alteration in egg or sperm, higher chance of developing second hit in the cell. Cause cancer family syndromes

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

Describe the cell cycle.

A 
Resting ->
(tumour suppressor genes) ->
Synthesis ->
DNA repair genes ->
G2 ->
Mitosis ->
G1 cell growth (oncogenes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What occurs after 1 mutations of oncogene?

A

Accelerated cell division

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

Give an example of a cancer caused by tumour suppressor related gene mutation.

A

Retinoblastoma

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

What happens from 1st and 2nd mutations of tumour suppressor genes?

A

1st = susceptible carrier

2nd mutation or loss = leads to cancer

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

What is the main mechanism for familial cancer?

A

Faulty DNA mismatch repair

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

What causes Lynch syndrome?

A

Mutation in mismatch repair genes

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

What is the sequence for polyp formation in Lynch syndrome/ HNPCC?

A

Adenoma - carcinoma sequence

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

What cancers are likely in those with Lynch syndrome?

A 
Colorectal
Endometrial 
Urinary tract 
Ovarian 
Gastric
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the chances of breast cancer in a female if you have BRCA1 and 2?

A

60-80%

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

What do males with BRCA2 have an increased risk of?

A

Prostate and breast cancer

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

When should you suspect hereditary cancer syndrome?

A

Cancer in 2 or more close relatives (on same side of family)

Early age of diagnosis

Multiple primary tumours

Bilateral or multiple rare cancers

Characteristic pattern of tumours

Evidence of autosomal dominant transmission

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

What should be included in a clinical genetics consultation?

A

FH, risk estimation, explain risk, genetic testing, interventions (increased awareness of symptoms/signs, lifestyle e.g diet and exercise, prevention, screening, prophylactic surgery)

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

What is the recommendation for CRC surveillance?

A

2 yearly for gene carriers ages 25/35

5 yearly from 50 if moderate risk

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

What tests are available for Lynch syndrome?

A

IHC (immunohistochemistry) for mismatch repair gene proteins or MSI

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

Discuss some benefits of genetic testing?

A

Identifies high risk
Identifies non-carriers in families with a known mutation
Early detection
Relive anxiety

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

Discuss some risks of genetic testing?

A

Doesn’t detect all mutations
Continued risk of sporadic cancer
Psychosocial or economic harm

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

Who is referred for genetic testing?

A

1st, 2nd and 3rd degree relatives

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

What are potential modes of inheritance in multi-system disorders?

A
  • Chromosomal
  • Single gene disorders (dominant, receive, X-linked)
  • Multifactorial (polygenic, environmental)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are common problems in multi-system disease?

A

Variable expression within as well as between families

Present to a large variety of different specialists

Family history easily missed

22
Q

What is neurofibromatosis?

A

Autosomal dominnant multisystems disease

23
Q

What is the diagnostic criteria for neurofibromatosis?

A

Need 2+ of…

  • Cafe au last spots (6 or more)
  • Neurofirbromas
  • Axillary freckling
  • Lisch nodules (on iris)
  • Optic glioma
  • Thinning of long bone cortex
  • FH
24
Q

What are other features of NF1?

A 
Macrocephaly
Short stature
Dysmorphic (Noonan look)
Learning difficulties
Epilepsy 
Scoliosis
Raised BP
Neoplasia
25
Q

How is NF1 managed?

A 
BP
Spine for scoliosis
Tibia for unusual angulation 
Visual acuity and visual fields 
Educational assessment 
Asp patient to report any unusual symptoms
26
Q

What do we worry about in patients with NF1?

A

Tumour growth

27
Q

What are the genetics of NF1?

A 
Autosomal dominant 
Variable expression 
Gene identified (17q)
Mutations different in different families 
50% due to new mutations
28
Q

What are the main features of NF2?

A

Acoustic neuromas
CNS and spinal tumours
a few CAL spots

29
Q

What gene is NF2 mutation on?

A

22

30
Q

What is the classic triad for tuberous sclerosis?

A

Epilepsy
Learning difficulty
Skin lesions

31
Q

What is the pathology of tuberous sclerosis?

A

Harmatomas (overgrowth) in different organs

32
Q

How do you investigate tuberous sclerosis?

A

Clinical examination
Cranial MRI (if seizures)
Renal ultrasound
Echo

33
Q

What are signs of myotonic dystrophy?

A 
Bilateral late onset cataract 
Muscle weakness, stiffness and myotonia
Low motivation 
Bowel problems 
DIabetes
Heart block 
Congenital myotonic dystrophy
34
Q

Discuss the genetic change in myotonic dystrophy.

A

Autosomal dominant in CAG repeat

35
Q

Why are adults referred to genetics?

A 
Diagnosis
Predictive etesting 
Carrier testing 
FH 
Fetal loss or recurrent miscarriage
36
Q

What are the mechanisms of adult onset genetic disease?

A

Single gene
Chromosomal
Mitochondiral
Multifactorial

37
Q

What are causes of genetic diseases?

A

Environmental + genetics

on a spectrum, can be mix of both factors

38
Q

What genetic diseases are easier to predict?

A

Single gene disorders with high penetrance.

Multifactorial conditions harder to predict

39
Q

What is shared genetic heritage?

A

Genetic disease affects families, not individuals

discovery of a genetic disorder implies risk for relatives

40
Q

Give an example of a single gene disorder with high penetrance

A

Huntington’s

41
Q

Discuss the genetics of motor neuron disease.

A

Autosomal dominant
male-male transmission seen
at least 2 non-penetrative individuals

42
Q

What % of ALS is familial?

A

5-10%

43
Q

What are features of ALS?

A

Progressive muscle weakness, wasting and increased reflexes (upper and lower neuron signs), limb and bulbar muscles involved, cognition spared, pure motor signs with fasciculations

44
Q

Would you test someone for motor neuron?

A

No cure, no satisfactory treatment, incomplete penetrance

Impact on insurance?
Risks to employment?
Variability in condition

45
Q

What is the mutation that causes Huntington’s?

A

Mutation in CAG repeat

46
Q

What are benefits of Huntington’s genetic testing?

A

If negative - concerns about self and offspring reduced

If positive - can make plans for future, arrange surveillance/treatment, inform children or decide whether to have children

47
Q

What are the disadvantages of predictive testing if test are positive?

A 
Removes hope
Continues uncertainty
Known risk to offspring 
Impact on self/partner/family/friends
Potential problems with insurance/mortgage
48
Q

What are the disadvantages of predictive testing if test are negative?

A

Expectations of a good result

Survivor guilt

49
Q

What are the principles of ethics in medicine that need to be considered for genetic testing?

A

Respect for autonomy
Beneficence
Non-maleficence
Justice

50
Q

When should you carry out genetic testing on children and adults?

A

Only if there is potential medical benefits

Speciality teaching (4 decks)

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