Variant Description Extractor Exercise

The Variant Description Extractor is a new tool, which compares the reference sequence with the observed variant sequence and generates a basic description according to the standard human sequence variant nomenclature.

This exercise aims to introduce the basic principles of variant descriptions. The Variant Description Extractor uses g. position numbering starting with the first nucleotide as position 1.

1. Copy the Reference sequence example into both Reference sequence and the Observed sequence fields. Press the Submit button.

The = indicates that the Observed sequence is the same as the Reference sequence.

For questions 2-4 of the exercise you only have to modify the Observed sequence and answer the questions before you press the Submit button.

2. Change the second A into a T.

What is the g. position of the change? What type of change is this?

3. Delete the Ts at position 4 and 5.

What is the type of change and how is it described?

4. Delete the G at position 3.

What would be the range of the deletion according to instructions 3 and 4? Can you find another range of nucleotides leading to the same observed sequence?

Press the Submit button.

Is the result what you expect?

5. Copy the Reference sequence example into the Observed sequence field and insert a G following the first one.

What is the type of change and how is it described?