Brainscape's Knowledge GenomeTM

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


See full index

Human Diseases BIOL2211 > Genetically Inherited Diseases > Flashcards

Genetically Inherited Diseases Flashcards

1
Q

What are the three points of the etiology triangle of disease?

A

100% environmental
Single gene
Polygenic

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

What are some diseases typically associated with genes?

A

Duchenne Muscular Dystrophy
Haemophilia
Osteogenesis imperfecta

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

What are some diseases typically associated with the environment?

A

Tuberculosis and Scurvy

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

What are some diseases typically associated with both genes and the environment?

A

Spina bifida

Pyloric stenosis

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

What are some features of more genetic diseases?

A

Unifactorial
Rare
Mendelian - so high recurrence rate

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

What are some features of more environmental diseases?

A

Still genes involved but more polygenic
Multifactorial
Common
Low recurrence rate

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

What does it mean if a disease is multifactorial?

A

Caused by genes and the environment (drugs, infections) - variation in genes causing alteration of function - one organ system affected

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

What does it mean if a disease is single gene?

A

One mutation - normally loss of function - dominant/recessive pedigree patterns - can affect structural proteins, enzymes, receptors and transcription factors

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

What does it mean if a disease is chromosomal

A

Whole stretched of genome deleted (thousands of genes involved) (can be seen with cytogenically down a microscope) - chromosomal imbalance which causes alteration in gene dosage - affects multiple organ systems affected at multiple stages in gestation; can be inherited in rare cases

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

What does it mean if a disease is mitochondrial?

A

Mutation in the mitochondrial DNA

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

What does it mean if a disease is germline?

A

Still single cell mutations but more infrequent - sporadic mutations in onca and tumour genes

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

What are some of the impacts of childhood genetic disorders?

A

50% deafness/blindness/sever MR
25% in patient visits
40-50% deaths

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

What are some of the impacts of adult genetic disorders?

A

5% disorders/diseases

10% common cancers

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

Describe how metaphase spread works?

A

Stained with giesma
Dark region show dense bunched up DNA
Pale regions show less condensed DNA

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

What are acrocentric chromosomes?

A

P arm is much smaller than Q arm

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

What is a syndrome?

A

A disorder with a collection of features

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

What causes Down’s syndrome?

A

Trisomy of chromosome 21

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

What are some of the collective features of Down’s syndrome?

A 
Round face
Protruding tongue
Up-slanting palpebral fissures
Epicanthic folds of eye
Developmental delay
19
Q

How can Down’s syndrome be diagnosed?

A

Can be diagnosed in utro prenatally so is screened for in pregnancy

20
Q

What features can be seen on the ultrasound?

A 
Short femurs
Nuchal translucency
Echogenic bowel
Choroid plexus cyst
Sandal gap, single palmar crease
21
Q

What are the three different patterns of chromosomes that can cause Down’s syndrome?

A
  1. 95% people have three separate copies of chromosome 21
  2. 4% have extra copy of chromosome 21 because of Robertsonian translocation
  3. 1% have mosaicism with normal and trisomy 21 cell lines (and usually have much milder features because of the presence of normal cells) – occurs post zygotically
22
Q

What causes Patau syndrome?

A

Trisomy of chromosome 13

23
Q

Compare Patau syndrome to Down’s syndrome

A

More severe

24
Q

What are some collective features of Patau syndrome?

A 
Affects midline structures:
Incomplete lobation of the brain
Cleft palate
Congenital heart disease (arterial septal defect)
Inguinal hernia
Postaxial polydactyly
25
Q

What is the prognosis for Patau syndrome?

A

Poor prognosis - majority of babies die within first few weeks of life; if baby survives severe mental retardation

26
Q

Why do trisomies occur?

A

When there is no disjunction (correct segregation) in meiosis, disomic and nullisomic gametes are formed. If a disomic gamete was to fuse with a monosomic gamete (spermatocyte and oocyte) a trisomy would form.

27
Q

What are numerical chromosome abnormalities?

A

Gain or loss of complete chromosomes

28
Q

What are the results of numerical chromosome abnormalities?

A

Serious, often lethal consequences (particularly autosomal) - MCA/MR syndromes

29
Q

Name four microdeletion syndromes

A

DiGeorge syndrome
William’s syndrome
Prader-Willi syndrome
Cat Eye Syndrome

30
Q

What causes DiGeorge Syndrome?

A

22q11.2 microdeletion

31
Q

What are the features of DiGeorge Syndrome?

A 
Small mouth
Prominent nose
Congenital heart defects 
Abnormal facies
Thymic aplasia
Cleft palate
Hypocalcaemia/Hypoparathyroidism
32
Q

What causes William’s Syndrome?

A

7q11.23 microdeletion (about 26 genes from long arm of chromosome 7)

33
Q

What are the features of William’s syndrome?

A 
Bright eyes
Stellate irises
Wide mouth
Upturned nose
Long philtrum
Flattened nasal bridge
Heart defects 
Inappropriately sociable
34
Q

What causes Prader-Willi syndrome?

A

15q13 microdeletion

35
Q

What are the features of Prader-Willi syndrome?

A

Hypotonia and abnormal neurological function
Hypogonadism
Developmental and cognitive delays
Hyperphagia
Obesity
Short stature
Behavioural and psychiatric disturbances
Constant, extreme, ravenous insatiable appetite
Marked skill in completing jigsaw puzzles

36
Q

What causes Cat eye syndrome?

A

22 inverted duplication 22q11

37
Q

What are the features of Cat eye syndrome?

A 
Iris coloboma
Anal atresia
Ear tags and/or ear pits
Heart defects
Kidney malformations
Marked variability
38
Q

What is a pedigree?

A

Short hand to record a family tree

39
Q

Why is diagnostic testing?

A

Part of clinical management. Confirm/refute clinical diagnosis. Assess carrier status

40
Q

Who is diagnostic testing for?

A

Test an individual with a family history of the illness or other clinical indication. If early diagnosis reduces morbidity or mortality.

41
Q

What is a karyotype?

A

Represents the cytogenetic characteristics of the individual - stained with giemsa for G banding

42
Q

Which specimen contain spontaneously proliferating cells?

A

Bone marrow
Lymph nodes
Solid tumours
Chorionic villi (CVS)

43
Q

Which specimens are routinely cultured in the laboratory?

A

Blood lymphocytes
Tissue biopsies (fibroblasts from skin etc)
Amniotic fluid samples
Long term CVS

Human Diseases BIOL2211 (5 decks)

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