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

Table 3

Somatic point mutation patterns in the TP53 coding region in “All Ovary” Cancers.

Original base	Mutant base
	A	T	C	G	Total		Statistics
A (22%)^†	—	2.1	1.6	13.0	16.7	A≫T	1.6x	𝑃<0.001
T (21%)	2.9	—	4.1	3.3	10.3	A>G versus T>C	3.2x	𝑃<0.001
C (29%)	2.1	19.4	—	4.6	26.1	G≫C	1.8x	𝑃<0.001
G (28%)	30.6	12.3	3.9	—	46.9	G>A versus C>T	1.6x	𝑃<0.001
						G>T versus C>A	5.9x	𝑃<0.001
						G>C versus C>G	0.9x	NS

Values in the table represent the percentage of the total of 1575 somatic point mutations scored in category “All Ovary” (R15). ^†The percentage base composition in the TP53 coding region for 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 122 are at non-CpG and 183 are at CpG sites; for G-to-A mutations 222 are at non-CpG and 260 are at CpG sites.