The Future of Genomic Medicine

Question 1

How many base pairs are there in the complete human genome?

Answer 1

6 billion

Question 2

Give an example of pharmacogenomics being used to get the dosage right

Answer 2

6-mercaptopurine is used to treat leukaemia, Crohn’s disease and ulcerative colitis
People who have two normal copies of the TPMT (thiopurine methyl transferase) gene metabolise the drug fast and so have a high dose Some people are heterozygous for a mutation in TPMT so they metabolise the drug slower and so have more side effects. This means that they get a reduced dose.
Very few people are homozygous for a mutation in TPMT – they barely metabolise the drug at al

Question 3

Give an example of pharmacogenomics being used to get the drug right.

Answer 3

Type 1 Diabetes and Mature Onset Diabetes of the Young (MODY)
MODY can be treated with oral drugs but is commonly misdiagnosed as T1D and so patients may be getting unnecessary insulin injections.

Question 4

Give two examples of diseases for which DNA sequencing has been used to find the mutations responsible

Answer 4

Miller Syndrome

Schinzel-Giedeon Syndrome