Developmental genetics and teratology Flashcards
What are 6 Wilson principles of teratology?
- Susceptibility depends on genotype and environmental interact
- Susceptibility varies with developmental stage
- Teratogenic agents act in specific ways
- Mutagenic access depends on nature of agents
- Four manifestations: death, malformation, growth retardation and functional deficit
- Dosage effect
What is teratoma?
A tumour that develops from inappropriate cell specialisation
What is human organiser?
Node
How does human organiser influence the layout of body?
- Cells in node contain specialised cilia whose structure and angle create a leftward current
- Left sided rise in intracellular Ca2+ increases cascade of nodal expression in left lateral plate mesoderm
What are another names of Down syndrome, Edwards syndrome and Patau syndrome?
- Down syndrome: Trisomy 21
- Edwards syndrome: Trisomy 18
- Patau syndrome: Trisomy 13
What syndrome(s) are associated with aneuploidy?
- Turner syndrome
- Klinefelter syndrome
- Every affected person has an affected parent
- Every affected father passes it on to all of his daughter and none of his sons
What is mode of inheritance?
X-linked dominant
- Every affected person has an affected parent
- Every affected father passes it on to his daughter and sons
What is mode of inheritance?
Autosomal dominant
- Every affected person does not have an affected parent
- There is an affected female without an affected father
What is mode of inheritance?
X-linked recessive
- Every affected person does not have an affected parent
- There is an affected female with an affected father
- More males are affected than females
What is mode of inheritance?
X-linked recessive
- Every affected person does not have an affected parent
- There is an affected female with an affected father
- Equal sex ratio
What is mode of inheritance?
Autosomal recessive
What is an example of autosomal dominant?
Achondroplasia
What is an example of autosomal recessive?
Tay-Sachs disease (HexA deficiency leading to lipid accumulation in brain)
What is an example of X-linked dominant?
Rett syndrome (neurological disorder of grey matter)
What is an example of X-linked recessive?
Duchenne muscular dystrophy
What is an example of Y linked?
Slyer syndrome (gonadal dysgenesis)
What is an example of mitochondrial inheritance?
LHON
What are multifactorial disorders?
Complex diseases: genes + environment
What are multifactorial disorders that develop early?
- Autism
- Asthma
- Cleft palate
What are multifactorial disorders that develop late?
- Heart disease
- Diabetes
- Hypertension
What does TORCH stand for?
- Toxoplasmosis
- Other (e.g chicken pox, chlamydia, HIV, syphilis, hepatitis, zika)
- Rubella
- CMV
- HSV2
Examples of maternal illnesses that lead to congenital abnormalities
- Diabetes mellitus
- Phenylketonuria
Examples of drugs that lead to congenital abnormalities
- ACE inhibitor
- Streptomycin
- Warfarin
- Valproic acid
Examples of chemicals that lead to congenital abnormalities
- Thalidomide
- Alcohol
- Smoking
- Cocaine
