Frameshift mutation is the addition or loss of nucleotides. To be classed as a frameshift mutation the addition or loss cannot be a multiple of three. This is an accidental change in the genomic sequence and therefore a genetic mutation and results in a different protein being translated. If the mutation occurs earlier on in the sequence then the frameshift will be potentially more severe and the resulting protein produced usually being non-functional. The length of the protein can also be affected with new stop codons being translated. The mutations can also lead to diseases, one of which is Tay-Sachs.
Tay-Sachs disease is a type of GM2-gangliosidosis group of neurological disorders and results in the deterioration of mental and physical abilities. The disease results from many different types of mutation; these include eight frameshift mutations, two insertion and 6 deletion indels. Different populations are found to have different severities of mutation to the gene that encodes the alpha-subunit and beta-hexosaminidase A of a lysomal enzyme. In Ashkenazi Jewish population they have 10-fold higher gene frequency for the severe form of the disease due to an insertion causing the frameshift mutation. In the French Canadian population a large deletion of 7.5 kilobases is the major mutation found causing the disease.