Sickle cell anaemia is an example for which of the following type of mutations?

Sickle cell anaemia is caused due to change in sixth amino acid glutamic acid to valine in β-polypeptide chain of haemoglobin or RBC. The codon for glutamic acid is GAG.  In the template DNA strand the corresponding complementary sequence is CTC. CTC is changed to CAC i.e. a pyrimidine T is replaced by purine A and such type of replacement of a purine with pyrimidine or vice versa is called transversion substitution mutations. In transition mutation a purine is replaced by a purine or pyrimidine is replaced by pyrimidine. Frame shift mutation is due to deletion or addition of pairs of nucleotides in a DNA. Chromosomal mutations are due to change in number and structure of chromosomes.