Lecture 2- Clinical Bioinformatics

Question 1

What does Next Generation Sequencing determine

Answer 1

The nucleic acid sequence of a given DNA molecule

Question 2

Method of Next Generation sequencing

Answer 2

1. Fragment dna and add adapters to the end of fragments
2. Fragments are amplified by creating complementary molecules which forms a double strand that then separates
3. Flourescently tagged nucleotides are added tp the growing chain
4. Light source excites the clusters, fluorescent signal emitted

Question 3

Strengths of NGS

Answer 3

Lots of dna can be sequenced 
Can detect abnormalities across entire genome including insertions, deletions, duplication, copy number changes, chromosome inversions/ translocations 
Less costly 
Faster turnaround time 
Uses less dna

Question 4

Limitations of NGS

Answer 4

Requires computational resources and large data stores etc

Question 5

1 in how many people does a rare disease affect

Answer 5

1 in 2000 people

Question 6

What % of rare diseases have a genetic component

Answer 6

80%

Question 7

What % of the population will be affected by a rare disease

Answer 7

7%

Question 8

What % of rare disease affect children

Answer 8

75%

Question 9

Cockayne’s syndrome is caused by a mutation in which genes

Answer 9

ERCC6 or ERCC8

Question 10

What kind of proteins are the genes ERCC6 AND ERCC8 and what is thier function

Answer 10

DNA excision repair protein

Provide instructions for making proteins involved in repairing damaged DNA

Question 11

Why does Cockaynes syndrome underlie photosensitivity

Answer 11

DNA can be damaged by UV rays and the gene mutations of ERCC6 ERCC8 mean that this damage isn’t repaired normally, errors build up in DNA, cells malfunction and die

Question 12

What are the 4 types of Cockayne Syndrome

Answer 12

Type I = classic/ moderate form
Type II = more severe, symptoms at birth, overlaps with COFS or Pena- Shokier syndrome type 2
Type III = milder
Xeroderma Pigmentosum = XP-CS= symptoms such as severe sunburn after only a few minutes in the sun, freckling in sun exposed areas, dry skin and changes in skin pigmentation.

Question 13

How many types of Cockayne syndrome are there.

Answer 13

4

Question 14

Do children with CS have a shortened life span

Answer 14

Most with clinically severe SC do not survive to 7

Question 15

How to help child with CS

Answer 15

Protect skin/ eyes from sun. Avoid falls. Dental hygiene

Question 16

What is the minimum incidence of CS

Answer 16

About 2.7 per million births