Genetics of Development Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

How many babies are affected by congenital anomalies?

A

1 in 20 babies

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

Why are congenital animalities so dangerous?

A

Extremely lethal

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

What is cyclopia?

A

Most severe form of holoprosencephaly

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

Why is cyclopia so severe?

A

Due to a lack of connections on the midline and gaps in the brain.

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

What is the mildest form of cyclopia?

A

Single midline incisor tooth

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

What is cyclopia caused by?

A

Chromosomal abnormalities eg. Trisomy 13

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

What are the Common congenital anomalies in live births?

A
  • Craniofacial Anomalies
  • Neural tube defects
  • Congenital Heart Defects
  • Congenital Kidney Disease
  • Multisystem Anomalies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What kinds of Craniofacial Anomalies are there?

A

Cleft Lip/Palate

Craniosynostosis

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

What are Craniosynostosis?

A

Bones in the head fuse prematurely.

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

What is the cause of congenital anomalies, genetically?

A

Most are unknown but all discoverable.

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

What is the VUS?

A

A variant of uncertain significance is a genetic change whose clinical impact is not understood.

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

How long is a human pregnancy?

A

38-40 weeks.

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

What is human pregnancy usually broken up into?

A

Embryonic and fetal stage

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

When is the embryonic stage?

A

Up to 8 weeks

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

When is the fetal stage?

A

8 weeks to term.

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

When does oganogenesis occur?

A

During embryogenesis

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

When do congenital anomalies occur?

A

First 8 weeks usually

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

What are congenital anomalies caused by physical?

A

Abnormal development of the embryo/fetus

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

What can be used to study genes regulating development?

A

Model organism

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

What does it mean when genes regulating development are conserved?

A

This means they were kept from ancestors through evolution and are often shared between species.

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

What is the Pax6 example of development gene conservation?

A

If you knockout pax6 the mouse is born with no eyes

If you remove the pax6 gene from a mouse and add it to a knockout fly it is born with eyes.

Pax6 gene similar between the two.

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

What are the patterns of anomalies?

A

Isolated

Syndromes

Sequences

Associations

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

What is an isolated pattern?

A

Single organ/structure affected

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

What is a syndrome?

A

Multiple organs/structures affected, shared aetiology

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

What is a sequence patten?

A

Multiple organs/structures
affected, development is interconnected.

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

What is am association pattern?

A

Multiple organs/structures affected, too common to be just chance but no clear shared aetiology

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

What kind of patten is a cleft palate?

A

Isolated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What kinds of genetics cause a cleft palate?

A

TBX22

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where is TBX22 expressed?

A

Developing orofacial cavity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is Holt-Oram (“hand-heart”) syndrome?

A

Holt-Oram patients have defects in the upper limbs and the heart

31
Q

How is Holt-Oram (“hand-heart”) syndrome inherited?

A

Autosomal dominant

32
Q

What kinds of genes cause Holt-Oram (“hand-heart”) syndrome?

A

TBX5

33
Q

Where is TBX5 expressed?

A

In the heart and the forelimbs (but not hindlimbs).

34
Q

What is the Pierre-Robin sequence?

A

Defects in the lower jaw, palate, breathing difficulties and failure to thrive.

35
Q

How is Pierre-Robin sequence inherited?

A

Not generally inherited – thought to be de novo mutations in multiple genes.

36
Q

What is the initial defect in Pierre-Robin sequence?

A

Micrognathia

37
Q

What is micrognathia?

A

A condition in which a child has a very small lower jaw.

38
Q

How is Pierre-Robin sequence fatal?

A

Tongue is displaced which stops the palate closing and blocking airway.

39
Q

What is VACTERL association?

A
  • Vertebral defects
  • Anal atresia
  • Cardiac defects
  • Tracheo-Esophageal fistula
  • Renal abnormalities
  • Limb anomalies
40
Q

What is VACTERL association caused by?

A

Cause unknown (not inherited).

41
Q

What kinds of environmental causes are there for congenital anomalies?

A

Viruses

Maternal illness

Drugs

Pollutants

Diet

42
Q

What kinds of genetic causes are there for congenital anomalies?

A

Chromosomal defects

Single genes

Multi-gene interactions

43
Q

When is zika virus most dangerous?

A

During pregnancy.

44
Q

What happens to the baby when the mother gets zika virus?

A

Microcephaly

45
Q

What is microcephaly?

A

The head is very small and therefore so is the brain.

46
Q

When are the biggest risk of getting zika virus?

A

First and second trimester.

47
Q

How many pregnancies result in miscarriage?

A

10-15%

48
Q

What percentage of miscarriages have chromosomal abnormality?

A

50%

49
Q

What are chromosomal abnormalities caused by?

A

Non-disjunction events during meiosis

50
Q

What is caused by non disjunction events during meiosis?

A

Whole or part of chromosome extra/missing therefore multiple genes affected.

51
Q

What is the main risk for chromosomal activity?

A

Maternal age.

52
Q

Why is maternal age the main risk factor for chromosomal abnormality?

A

Oocytes halt in metaphase II stage of meiosis for up to 40 years.

53
Q

What is DiGeorge Syndrome?

A

Characteristic facial
appearance

Congenital heart defects

Thymus and parathyroid
hypoplasia

54
Q

What is the genetic cause for DiGeorge syndrome?

A

Deletion of chromosome 22q11.2

~30 genes deleted

Haploinsufficiency for TBX1

55
Q

What is the Ulnar-mammary syndrome?

A

Posterior limb deficiencies

Delayed puberty in males

Genital anomalies

56
Q

What gene is Ulnar-mammary syndrome?

A

TBX3

57
Q

What is the homeobox?

A

Contains the Genes of the Hox family.

DNA binding region

58
Q

What are hox genes?

A

Transcription factors that regulate the expression of other genes that specify body parts

59
Q

Where is 22q11.2?

A

At the end of the chromosome.

60
Q

What do Neural tube defects result in?

A

Elective TOP or still birth

61
Q

What are Neural tube defects caused by?

A

Caused by abnormalities in the normal process of neurulation

62
Q

What are the prevention measures of birth defects?

A

Folic acid (B vitamin) reduces the risk of neural tube defects by up
to 35%

400 mg daily

B vitamins (inositol)

63
Q

What is cilia?

A

Complex microtubule-based structures that project from the cell
surfacre

64
Q

What are the 2 main types of cilia?

A

motile and primary

65
Q

What is the function of cilia?

A

Movement

Sensing

Signalling

66
Q

Where do mutations in motile cilia affect?

A

Organ placement

Infertility

Brain

Respiration system

heart

67
Q

Where do mutations in non-motile cilia affect?

A

Eyes

Nose

Ears

Energy

Skeleton

Reproduction

Brian

Kidney

Liver

68
Q

What can mutations in the cilia which affect movement cause?

A

Mutations in cilial genes found in patients with male infertility and severe persistent airway infections

69
Q

What can mutations in the cilia which affect sensing cause?

A

Retinitis pigmentosa

70
Q

What can mutations in the cilia which affect signalling cause?

A

Nephronophthisis and polycystic kidney disease

71
Q

What is SHH gene?

A

Sonic Hedge Hog

72
Q

What is the function of SHH?

A

Development in cell growth, specialization and normal shaping.

73
Q
A