L18: Genomic Medicine

Question 1

What is the difference between short and long read sequencing?

Answer 1

• short read sequencing (illumina), read length 150-200 base pairs (dominated for 20 years)
• long read sequencing (PacBio, Oxford Nanopore (measures electrical signals)), read length: 20,000 - 1 million base pairs, much quicker

Question 2

What is genomic medicine?

Answer 2

The use of genetic information and genomic tools to determine disease risk and predisposition, diagnosis, prognosis, and the selection and prioritisation of therapeutic options

Question 3

What is the difference between single gene and genetically complex disorders?

Answer 3

• single-gene disorders: a variant in a single gene is the primary determinant of this type of disease, is responsible for most of the disease risk, wtih possible minor contributions from modifier genes or environment
• complex disease: many variants of small effect contribute to disease risk, along with many environmental factors

Question 4

What are the examples of single gene inherited diseases? Are they common?

Answer 4

Rare - single gene: cystic fibrosis, haemophilia, Huntington’s disease, Tay Sachs disease

Question 5

What are the examples of genetically complex inherited diseases? Are they common?

Answer 5

common - genetically complex: heart attack, obesity, diabetes, rheumatoid arthritis

Question 6

What is GWAS catalog?

Answer 6

The GWAS catalog is a free online database that compiles data of genome-wide association studies, summarizing unstructured data from different literature sources into accessible high quality data.

Question 7

What is thoracic aortic aneurysm? Which gene is responsible?

Answer 7

A thoracic aortic aneurysm is a weakened area in the upper part of the aorta — the major blood vessel that feeds blood to the body. Causes swelling or bulging of the aorta in the chest.

Usually presents as incidental finding or as emergency chest pain.

Operative mortality of planned surgery <5%
operative mortality of emergency surgery >50%

considerabe advantage in pre-clinical diagnosis and planned surgery

Many genes found responsible, but one associated is FBN1, also associated with Marfanoid syndrome.

Question 8

What is liquid biopsy?

Answer 8

Tumours release dying cells and cell free DNA into the circulation, cell free DNA causes characteristics of malignant tumours, detects minimal residual disease, can show if cancer comes back after treatment, even though no symptoms occur