GEN: Discovery of Human Disease Genes

Question 1

what is autosomal dominant inheritance?

Answer 1

Question 2

what is autosomal recessive inheritance?

Answer 2

Question 3

what is X-linked recessive inheritance?

Answer 3

Question 4

in meiosis, how do the precursor cells muliply?

Answer 4

precursor cells of sperm or ova multiply and at the same time reduce the number of chromosomes to one full set

Question 5

what is the process in meiosis which allows for two chromosomes of a homologous pair to exchange segments?

Answer 5

recombination

Question 6

what does frequency of recombination between two locations depend on?

Answer 6

their distance

Question 7

what is genetic linkage?

Answer 7

recombination can occur at any chromosomal location → DNA regions in close proximity are more likely to be co-inherited

Question 8

what is LOD used for?

Answer 8

stats test (LOD score) to detect linkage presence

Question 9

what is the formula for LOD?

Answer 9

Question 10

what does a LOD score of more than 3 mean?

Answer 10

consistent with linkage

Question 11

what does a LOD score of less then -2 mean?

Answer 11

linkage can be excluded

Question 12

what does a LOD score between 3 and -2 mean?

Answer 12

uncertain - issue with statistical power

Question 13

what is exome sequencing?

Answer 13

sequencing protein coding regions of genome

Question 14

what is the size of the human genome?

Answer 14

3 billion base pairs

Question 15

how many variants are there in the human genome?

Answer 15

3 million

Question 16

what is the size of the human exome?

Answer 16

30-50 million base pairs

Question 17

what is the number of variants in the human exome?

Answer 17

20,000

Question 18

which is more cost effective between human genome sequencing and human exome sequencing?

Answer 18

genome = £1000/person

exome = £300/person

Question 19

what was the first exome sequencing gene found?

Answer 19

Hajdu Cheney Syndome - bone loss at fingers and bones: NOTCH2 mutations

Question 20

what did the 14 independent mutations found after gene sequencing lead to?

Answer 20

all lead to premature stop codons

Question 21

what is a major confounding factor?

Answer 21

genetic heterogeneity