Genetics of Development Flashcards
How many babies are affected by congenital anomalies?
1 in 20 babies
Why are congenital animalities so dangerous?
Extremely lethal
What is cyclopia?
Most severe form of holoprosencephaly
Why is cyclopia so severe?
Due to a lack of connections on the midline and gaps in the brain.
What is the mildest form of cyclopia?
Single midline incisor tooth
What is cyclopia caused by?
Chromosomal abnormalities eg. Trisomy 13
What are the Common congenital anomalies in live births?
- Craniofacial Anomalies
- Neural tube defects
- Congenital Heart Defects
- Congenital Kidney Disease
- Multisystem Anomalies
What kinds of Craniofacial Anomalies are there?
Cleft Lip/Palate
Craniosynostosis
What are Craniosynostosis?
Bones in the head fuse prematurely.
What is the cause of congenital anomalies, genetically?
Most are unknown but all discoverable.
What is the VUS?
A variant of uncertain significance is a genetic change whose clinical impact is not understood.
How long is a human pregnancy?
38-40 weeks.
What is human pregnancy usually broken up into?
Embryonic and fetal stage
When is the embryonic stage?
Up to 8 weeks
When is the fetal stage?
8 weeks to term.
When does oganogenesis occur?
During embryogenesis
When do congenital anomalies occur?
First 8 weeks usually
What are congenital anomalies caused by physical?
Abnormal development of the embryo/fetus
What can be used to study genes regulating development?
Model organism
What does it mean when genes regulating development are conserved?
This means they were kept from ancestors through evolution and are often shared between species.
What is the Pax6 example of development gene conservation?
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.
What are the patterns of anomalies?
Isolated
Syndromes
Sequences
Associations
What is an isolated pattern?
Single organ/structure affected
What is a syndrome?
Multiple organs/structures affected, shared aetiology
What is a sequence patten?
Multiple organs/structures
affected, development is interconnected.
What is am association pattern?
Multiple organs/structures affected, too common to be just chance but no clear shared aetiology
What kind of patten is a cleft palate?
Isolated
What kinds of genetics cause a cleft palate?
TBX22
Where is TBX22 expressed?
Developing orofacial cavity.