Long time I am struggling how to provide GISTIC2 required input like Num_Probes
and Segment_Mean
I have called somatic copy number by scatngs and I have copy number output file (attached);
https://www.dropbox.com/s/r6nef2v1j2di6q6/my.copynumber.caveman.csv?dl=0
This is few lines of scatngs copy number output
1,1,13116,665401,2,1,3,1
2,1,668374,96324627,2,1,2,1
3,1,96326095,96419709,2,1,1,0
In scatngs reference paper says in this file we have
Segment number
Chromosome
Start position (origin-1)
End position (origin-1)
Major copy number—normal
Minor copy number—normal
Major copy number—tumor
Minor copy number—tumor
scatngs also returns another output like below
https://www.dropbox.com/s/7i28vooixdp06c2/WTSI-OESO_121_1pre.copynumber.txt?dl=0
Chromosome Position Log R segmented LogR BAF segmented BAF Copy number Minor allele Raw copy number
rs62635286 1 13116 -0.0290741822638953 0.245246748556562 0.25 NA 3 1 2.35806652809599
rs75454623 1 14930 0.402869048014209 0.245246748556562 0.3095 NA 3 1 4.14031506947036
I am wondering how I can get Num_Probes
and Segment_Mean
From this files?
People say
Segment_Mean = log2(tumour copy number / 2)
So, does that mean I should add up Major copy number—tumor
and
Minor copy number—tumor
to get tumour copy number? for getting Num_Probes what should I do?
EDITED
people says
scatngs uses read counts at SNPs to generate calls and so the locations of the SNPs is what I need to generate the number of markers in each segment. (eg each SNP = 1 marker).
Do they mean, for instance if the position of SNP rs62635286 is 13116, so the num_prob is 13116?
Any help please?
Thanks a lot in advance