Lecture 15 - Clinical Genetics

Question 1

What are the main classes of genetic disorders?

Answer 1

Single gene mutations
Multifactorial diseases
Chromosomal abnormalities
Mitochondrial conditions

Question 2

What are the types of chromosomal abnormalities?

Answer 2

Numerical: 
-aneupolidy - monosomy or trisomy
-polyploidy - triploidy (three of every chromosome)
Structural:
-Translocations - reciprocal and robertsonian
-Deletions
-Duplications
-Inversions
Different cell lines:
-Mosaicsm

Question 3

What are the four main types of prenatal diagnosis?

Answer 3

Amniocentesis
Chorionic villus sampling
Free fetal DNA
Ultrasound

Question 4

When can amniocentesis by done and what is it?

Answer 4

Can be done from 15 weeks. Involves Ultrasound guided transabominal needle to sample some of amniotic fluid.

Question 5

When is free fetal DNA done and how is it done?

Answer 5

It is a blood test from 9 weeks and can look at the fetal DNA from cells that have entered mothers blood.

Question 6

When is Chorionic villus sampling done and how is it done?

Answer 6

From 11 weeks gestation. Involves ultrasound guided transabdominal needle. Directly samples fetal cells.