Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Specialities > Genetics > Flashcards

Genetics Flashcards

(60 cards)

Start Studying
1
Q

Which function do disease associated mutations alter?

A

Protein function

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

What percentage of breast cancer is hereditary?

A

5-10%

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

What percentage of ovarian cancer is hereditary?

A

5-10%

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

Name the two main hereditary causes of colorectal cancer and the percentage of case?

A

Lynch Syndrome/HNPCC: 5%

FAP: 1%

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

What are clonal expansions?

A

When mutations begin to build up in more than one cell e.g. not just once cell going bad

How tumours work

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

Name the features of germline mutations

A
  • Inherited from single alteration in egg or sperm
  • All cells in the offspring are affected
  • Are heritable
  • Cause cancer family syndromes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name the features of somatic mutations

A
  • Occur in nongermline tissues

- Are noninheritable

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

Where do oncogenes occur in the cell cycle?

A

G1 (cell growth)

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

Where do tumour suppressor genes and DNA repair genes occur in the cell cycle?

A

S (synthesis)

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

How many mutations does an oncogene need in order for cancer to develop?

A

One - leads to accelerated cell division

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

Which oncogene is responsible for leukaemia and where is it found?

A

ABL on the BCR-ABL Fusion Protein

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

Which cancer is hereditary and normally presents in early childhood?

A

Retinoblastoma - due to tumour suppressor gene mutations

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

How many mutations do tumour suppressor genes need to lead to cancer?

A

Two - either two mutations or mutation + loss of gene

One - leads to a susceptible carrier

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

Name a cancer which needs multiple mutations to progress to cancer

A

Colon cancer - each mutation progresses the cancer from hyper-proliferative epithelium to metastasis

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

Which mutation 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
16
Q

Name the features of lynch syndrome/ HNPCC

A
  • Mutation in mismatch repair genes
  • Excess of colorectal, endometrial, urinary tract, ovarian and gastric cancers
  • Adenoma: carcinoma sequence for polyp formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the clinical features of HNPCC?

A
  • Early but variable age at CRC diagnosis

- Commonly tumour in proximal colon

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

List the cancer risks in Lynch syndrome from highest to lowest

A 
Colon
Endometrial
Stomach
Biliary tract
Ovarian
Sebaceous gland
CNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the cancer risks for BRCA1 and 2 in females?

A

Breast cancer: 60-80%
Second Primary Breast Cancer: 40-60%
Ovarian Cancer: 20-50%

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

What are the risks of the BRCA1 and 2 gene for males?

A

Increased risk of prostate and breast cancer (esp. BRCA2)

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

Name the features of autosomal dominant inheritance

A
  • Each child has 50% chance of inheriting the mutation
  • No skipped generations
  • Equally transmitted by men and women
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What features would make you suspect a hereditary cancer syndrome?

A
  • Cancer in 2 or more close relatives (in same side of family)
  • Early age at diagnosis
  • Multiple primary tumours
  • Bilateral or multiple rare cancers
  • Characteristic pattern of tumours (e.g. breast and ovary)
  • Evidence of autosomal dominant transmission
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the process of cancer genetics?

A
  • Obtain detailed FH
  • Confirm diagnoses of cancer
  • Risk estimation
  • Counselling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Name the steps in a clinical genetics consultation for cancer

A
  • FH
  • Risk estimation
  • Explanation of basis of risk
  • Interventions (lifestyle, prevention, screening, surgery and awareness)
  • Genetic testing in high risk patients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the options for breast surveillance?
- Breast awareness - Early clinical surveillance - Annual or clinical breast exams - Mammography (moderate/high risk) - MR screening for highest risk
26
How does a prophylactic mastectomy for BRCA1/2 gene carriers work?
- Removes most but not all breast tissue - Significantly reduces breast cancer risk in women with FH - Total or subcutaneous mastectomy - BRCA1 mutation positive women breast cancer incidence reduced to 5%
27
How does a prophylactic oophorectomy work?
- Eliminates risk of ovarian cancer - Peritoneal carcinomatosis may still occur - Laparoscopic reduces postsurgical morbidity - Induces surgical menopause but HRT till 50 does not chance BRCA risk - Risk of subsequent BRCA halved in mutation positive women
28
What are the surveillance options for CRC?
Colorectal: colonoscopy Endometrial: symptom awareness and surgery
29
What are the genetic testing options for lynch syndrome?
IHC for mismatch repair gene proteins or micro satellite instability testing (MSI) Gene screen if IHC/MSI are high
30
What are the benefits of genetic testing?
- Identifies highest risk - Identifies non-carrier in families with a known mutation - Allows early detection and prevention strategies - May relieve anxiety
31
What are the risks and limitations of genetics testing?
- Does not detect all mutations - Continued risk of sporadic cancer - Efficacy of interventions is variable - May result in psychosocial or economic harm
32
Which relatives are considered first degree relatives?
Father, mother, siblings and children
33
Which relatives are considered second degree relatives?
Aunts, uncles and grandparents
34
Which relatives are third degree relatives?
First cousins
35
Which modes of inheritance are possible in multi-system disorders?
All modes are possible: - Chromosomal: numerical or structural - Single gene disorders: autosomal dominant, autosomal recessive and X linked - Multifactorial: polygenic and environmental (e.g. haemachromatosis and diabetes)
36
Why can gene mutations result in multi-system disease?
- Several genes with diverse functions are involved - Single gene widely expressed in different tissues - Single gene tissue-specific expression but tissue integral part of many different systems
37
What are the common problems in multi-system disease?
- Variable expression within as well as between families - Present to a large variety of different specialists - Family history often missed
38
What is the mode of inheritance and prevalence of NF1?
Autosomal dominant | 1/2500-3500
39
What are the diagnostic criteria for NF1 (need 2 for diagnosis)?
- Cafe au lait spots: 6 or more - Neurofibromas: 2 or more - Axillary freckling - Lisch nodules (specks in iris) - Optic glioma - Thinning of long bone cortex - FH
40
Name the further features of NF1?
- Macrocephaly - Short stature - Dysmorphic Noonan look - Learning difficulties - Epilepsy - Scoliosis - Pseudoarthrosis of the tibia - Raised BP (due to renal a. stenosis or phaechromocytoma) - Neoplasia: CNS (optic gliomas) or endocrine
41
Which features of NF1 are checked during the annual review?
- BP - Spine for scoliosis - Tibia for unusual angulation - Visual acuity and visual fields - Educational assessment - Ask patient to report any unusual symptoms
42
Which gene is involved in NF1?
17q - tumour suppressor gene Mutations are different in different families and 50% are due to new mutations (usually paternal in origin)
43
What are the main features of NF2?
- Acoustic neuromas (usually bilateral) - CNS and spinal tumours - A few CAL spots - Gene is on chromosome 22
44
What is the incidence of tuberous sclerosis (TS)?
1 in 7000 newborns
45
What is the classic triad of tuberous sclerosis?
Epilepsy, learning difficulty and skin lesions
46
What is the mode of inheritance of TS?
Autosomal dominant
47
What are the genetics of TS?
- Variable expression - Almost full penetrance if fully investigated - 2 genes on different chromosomes cause identical phenotypes (TSC1 and 2)
48
What are the clinical features of TS?
- Variable expression (asymptomatic to severe handicap) - Learning difficulty in 40%: autistic features common - Seizures in 65%: infantile spasms and myoclonic seizures - Skin lesions: angiofibromas and subungual fibromas etc. - Kidney: cysts and angiomyolipomata - Phakomas in eye - Rhabdomyomas in heart
49
How would you investigate TS?
- Exam: skin signs, Woods lamp, nails and retinal exam. - Cranial MRI - Renal USS - ECHO
50
What is the mode of inheritance of myotonic dystrophy and what is the genetic cause?
- Autosomal dominant | - CTG repeat: exhibits anticipation with increasing severity in each generation
51
What are the clinical features of myotonic dystrophy?
- Bilateral late-onset cataract - Muscle weakness, stiffness and myotonia - Low motivation, bowel problems and diabetes - Heart block
52
What are the potential consequences of myotonic dystrophy?
- Death post anaesthetic is possible if not monitored | - Congenital: death/severe muscle disorder and learning difficulty
53
What are the possible mechanisms of adult onset genetic disease?
- Single gene - Chromosomal - Mitochondrial - Multifactorial
54
What are the clinical features of Amyotrophic lateral sclerosis?
- Progressive muscle weakness, wasting and increased reflexes - Limb and bulbar muscles involved - Pure motor signs (with fasciculations) - Cognition spared - Death due to resp. failure
55
Which forms of the superoxide dismutase are found in humans?
- SOD1: located in the cytoplasm - SOD2: located in the mitochondria - SOD3: extracellular
56
What is the benefit of superoxide dismutase?
- Protects cells from free radical damage | - Also protects cells from DNA damage, lipid peroxidation, ionising radiation damage and protein denaturation
57
What is the penetrance of ALS?
Incomplete - no certainty even with mutation analysis
58
What are the genetic features of Huntington's Disease?
- Autosomal dominant - Adult Onset - Mutation: CAG expansion`
59
What are the clinical features of Huntington's disease?
- Chorea - Athetosis - Myoclonus - Rigidity - Cognitive changes: poor planning/memory and subcortical dementia - Personality change: irritable, apathetic, loss of empathy, disinhibition and self centred - Psychiatric: depression, paranoia and psychosis
60
What is the penetrance of Huntington's ?
Fully penetrant

Specialities (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions