How is information stored in genes?
Amino acid sequences
In which arrangement do DNA strands bind together?
What is the sugar forming the backbone of
Which bases pair in DNA?
And in RNA?
DNA strands are bound to which proteins?
Tons of DNA strands combine to form what?
How many base pairs are there in the human genome?
3 000 000 000
How many genes does each human have?
How many polymorphisms does each person have on average?
3 000 000
Which genetic testing technique is used to find
a) large changes affecting the entire genome (e.g extra chromosomes)
b) tiny changes affecting one or a few bases (e.g point mutation)?
a) Array genomic hybridisation (aCGH)
b) Next generation sequencing (NGS)
How does aCGH work?
Detects BIGGER changes (e.g big deletions, chromosome duplications)
Compare sample to control DNA and ask "Is there more or less DNA?"
If aCGH finds half as much DNA as the control, a ___ mutation has occurred.
If aCGH finds 50% more DNA than the control sample, a ___ mutation has occurred.
aCGH can only detect (balanced / unbalanced) chromosome changes.
Which genetic disorder is caused by a deletion in chromosome 22?
What are the symptoms of Digeorge syndrome?
Vision / hearing problems
Mouth deformities e.g cleft palate
Congenital heart disease
Hypoparathyroidism causing seizures
Which genetic test is used to identify Digeorge syndrome?
Picks up bigger genome changes (e.g deletions or duplications)
Digeorge syndrome is caused by a deletion in chromosome 22
•The cat sat on the mat
•The car sat on the mat
•The cat spa to nth ema t
•The cas ato nt hem at
•The cat on the mat
•The cat cat sat on the mat
Name each type of mutation.
Deletion mutation (out of frame >>>>)
Deletion mutation (in frame)
Triplet expansion mutation
When is NGS used?
Small changes to genome
e.g a mutation in one gene
What is an example of a disease which could be identified by NGS?
Kabuki makeup syndrome
wouldn't worry about remembering it
What does de novo mean?
An acquired mutation
Arising spontaneously in the patient
What is the percentage chance of finding a de novo mutation in a child with a developmental disorder?
For children with non-specific developmental disorders, which genetic test should be done first?
to try and find a small mutation
Although genetic tests are useful in diagnosing disease, what information is essential?
because there are too many genes to analyse