Problem:

I'm doing my High School biology final on Progeria, and am wondering what type of mutation causes this disease.

I know that the LMNA gene codes for the "prelamin A" protein, and that protein contains a farnesyl group that is then not able to be removed (in the case of Progeria). The abnormal form (with the farnesyl still attached) of prelamin A is then called progerin, and attaches to the nuclear rim resulting in an abnormally formed cell nucleus, making mitosis impossible.

Required:

Question: Is this a structural mutation? What sort of mutation is this?

Give reasoning with your answer.