Critical Analysis of Strand-Biased Somatic Mutation Signatures in TP53 versus Ig Genes, in Genome-Wide Data and the Etiology of Cancer

Table 6

Somatic point mutation patterns in the TP53 coding region in “Glioblastoma” cancers of brain.

Original base	Mutant base
	A	T	C	G	Total		Statistics
A (22%)^†	—	1.5	1.5	8.6	11.5	A≫T	1.6x	NS
T (21%)	1.2	—	3.6	2.3	7.1	A>G versus T>C	2.4x	𝑃<0.01
C (29%)	3.2	30.9	—	3.6	37.8	G≫C	1.2x	NS
G (28%)	32.5	7.4	3.9	—	43.7	G>A versus C>T	1.1x	NS
						G>T versus C>A	2.3x	𝑃<0.05
						G>C versus C>G	1.1x	NS

Values in the table represent the percentage of the total of 748 somatic point mutations scored in category “Glioblastoma” (R15). ^†The percentage base composition in the TP53 coding region codons 130–300 inclusive—the region which contains the vast majority of mutations spanning the DNA binding region. The Chi-squared statistics (significance levels) are essentially unaltered if mutation frequencies are corrected for base composition. Note for C-to-T mutations 57 are at non-CpG and 174 are at CpG sites; for G-to-A mutations 89 are at non-CpG and 154 are at CpG sites.