Mutation Analysis (MutSig 2CV v3.1)
Uterine Corpus Endometrioid Carcinoma (MSS)
04 October 2018  |  None
Maintainer Information
Maintained by David Heiman (Broad Institute)
Overview
Introduction

This report serves to describe the mutational landscape and properties of a given cohort, as well as rank genes and genesets according to mutational significance. MutSig 2CV v3.1 was used to generate the results found in this report.

  • Working with cohort: CPTAC3-UCEC-MSS

  • Number of patients in cohort: 50

Input

The input for this pipeline is an annotated .maf file describing the mutations called for each individual in the given cancer cohort, and their properties.

Summary
Results
Breakdown of Mutation Rates by Category Type

Table 1.  Get Full Table A breakdown of mutation rates per category discovered for this cohort.

left from change right n N rate ci_low ci_high relrate autoname name type
ACGT C t G 1337 237063331 5.6e-06 5.3e-06 6e-06 21 ACGT[C->t]G *CpG->T point
ACGT C fs G 146 474126662 3.1e-07 2.6e-07 3.6e-07 1.2 ACGT[C->fs]G *CpG->(G/A) point
ACGT C ts ACT 1192 3916933552 3e-07 2.9e-07 3.2e-07 1.1 ACGT[C->ts]ACT *Cp(A/C/T)->(A/T) point
ACGT A tfs ACGT 613 6363711705 9.6e-08 8.9e-08 1e-07 0.36 ACGT[A->tfs]ACGT A->mut point
ACGT C f ACT 146 1958466776 7.5e-08 6.3e-08 8.8e-08 0.28 ACGT[C->f]ACT *Cp(A/C/T)->G point
Lego Plots

The mutation spectrum is depicted in the lego plots below in which the 96 possible mutation types are subdivided into six large blocks, color-coded to reflect the base substitution type. Each large block is further subdivided into the 16 possible pairs of 5' and 3' neighbors, as listed in the 4x4 trinucleotide context legend. The height of each block corresponds to the mutation frequency for that kind of mutation (counts of mutations normalized by the base coverage in a given bin). The shape of the spectrum is a signature for dominant mutational mechanisms in different tumor types.

Figure 1.  Get High-res Image SNV Mutation rate lego plot for entire cohort. Each bin is normalized by base coverage for that bin. Colors represent the six SNV types on the upper right. The three-base context for each mutation is labeled in the 4x4 legend on the lower right. The fractional breakdown of SNV counts is shown in the pie chart on the upper left. If this figure is blank, not enough information was provided in the MAF to generate it.

Figure 2.  Get High-res Image SNV Mutation rate lego plots for 4 slices of mutation allele fraction (0<=AF<0.1, 0.1<=AF<0.25, 0.25<=AF<0.5, & 0.5<=AF) . The color code and three-base context legends are the same as the previous figure. If this figure is blank, not enough information was provided in the MAF to generate it.

CoMut Plot

Figure 3.  Get High-res Image The matrix in the center of the figure represents individual mutations in patient samples, color-coded by type of mutation, for the significantly mutated genes. The rate of synonymous and non-synonymous mutations is displayed at the top of the matrix. The barplot on the left of the matrix shows the number of mutations in each gene. The percentages represent the fraction of tumors with at least one mutation in the specified gene. The barplot to the right of the matrix displays the q-values for the most significantly mutated genes. The purple boxplots below the matrix (only displayed if required columns are present in the provided MAF) represent the distributions of allelic fractions observed in each sample. The plot at the bottom represents the base substitution distribution of individual samples, using the same categories that were used to calculate significance.

Significantly Mutated Genes

Column Descriptions:

  • codelen = the gene's coding length

  • nncd = number of noncoding mutations in this gene across the cohort

  • nsil = number of silent mutations in this gene across the cohort

  • nmis = number of missense mutations in this gene across the cohort

  • nstp = number of readthrough mutations in this gene across the cohort

  • nspl = number of splice site mutations in this gene across the cohort

  • nind = number of indels in this gene across the cohort

  • nnon = number of (nonsilent) mutations in this gene across the cohort

  • npat = number of patients (individuals) with at least one nonsilent mutation

  • nsite = number of unique sites having a non-silent mutation

  • Abundance (pCV) = Probability that the gene's overall nonsilent mutation rate exceeds its inferred background mutation rate (BMR), which is computed based on the gene's own silent mutation rate plus silent mutation rates of genes with similar covariates. BMR calculations are normalized with respect to patient-specific and sequence context-specific mutation rates.

  • Clustering (pCL) = Probability that recurrently mutated loci in this gene have more mutations than expected by chance. While pCV assesses the gene's overall mutation burden, pCL assesses the burden of specific sites within the gene. This allows MutSig to differentiate between genes with uniformly distributed mutations and genes with localized hotspots.

  • Conservation (pFN) = Probability that mutations within this gene occur disproportionately at evolutionarily conserved sites. Sites highly conserved across vertebrates are assumed to have greater functional impact than weakly conserved sites.

  • p = p-value (overall)

  • q = q-value, False Discovery Rate (Benjamini-Hochberg procedure)

Table 2.  Get Full Table A Ranked List of Significantly Mutated Genes. Number of significant genes found: 23. Number of genes displayed: 35. Click on a gene name to display its stick figure depicting the distribution of mutations and mutation types across the chosen gene (this feature may not be available for all significant genes).

rank gene longname codelen nnei nncd nsil nmis nstp nspl nind nnon npat nsite pCV pCL pFN p q
1 CTNNB1 catenin (cadherin-associated protein), beta 1, 88kDa 2406 61 0 0 16 0 0 2 18 18 8 1e-16 1e-05 0.0022 1e-16 9.1e-13
2 KRAS v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog 709 185 0 0 15 0 0 0 15 15 3 7.4e-16 1e-05 0.026 1e-16 9.1e-13
3 PIK3R1 phosphoinositide-3-kinase, regulatory subunit 1 (alpha) 2361 3 0 0 2 0 0 13 15 12 15 1e-16 0.14 0.22 3.3e-16 2e-12
4 PTEN phosphatase and tensin homolog (mutated in multiple advanced cancers 1) 1244 515 0 0 27 13 0 17 57 37 44 1e-16 0.046 0.96 5.6e-16 2.5e-12
5 TP53 tumor protein p53 1314 498 0 0 5 2 0 3 10 10 10 2.3e-15 0.13 0.009 1e-15 3.6e-12
6 ARID1A AT rich interactive domain 1A (SWI-like) 6934 13 0 0 3 6 0 10 19 17 18 1e-16 0.64 0.57 3.8e-15 1.1e-11
7 CTCF CCCTC-binding factor (zinc finger protein) 2224 15 0 0 2 3 0 3 8 7 8 1.6e-11 1 0.76 4.2e-10 1.1e-06
8 NCOR2 nuclear receptor co-repressor 2 7753 175 0 1 1 0 0 5 6 6 6 0.000025 6e-05 0.88 4.2e-08 0.000096
9 PIK3CA phosphoinositide-3-kinase, catalytic, alpha polypeptide 3287 2 0 0 18 0 0 3 21 20 14 0.00028 1e-05 0.011 5.9e-08 0.00012
10 LOR loricrin 943 1 0 0 1 0 0 3 4 3 4 6.2e-08 0.071 0.35 6.7e-08 0.00012
11 DNHD1 dynein heavy chain domain 1 14431 7 0 0 1 0 1 2 4 4 3 0.000059 0.005 0.0077 1.2e-07 0.00019
12 ARID5B AT rich interactive domain 5B (MRF1-like) 3603 308 0 0 0 1 0 5 6 6 6 3.5e-08 1 0.7 6.3e-07 0.00096
13 RRAS2 related RAS viral (r-ras) oncogene homolog 2 640 791 0 0 3 0 0 0 3 3 1 5e-05 0.001 0.8 8.9e-07 0.0012
14 LIN54 lin-54 homolog (C. elegans) 2298 200 0 0 0 0 3 0 3 2 2 0.00021 0.001 0.63 3.5e-06 0.0045
15 IL27 interleukin 27 750 520 0 0 0 0 0 3 3 3 1 0.00027 0.001 0.97 4.4e-06 0.0054
16 FGFR2 fibroblast growth factor receptor 2 (bacteria-expressed kinase, keratinocyte growth factor receptor, craniofacial dysostosis 1, Crouzon syndrome, Pfeiffer syndrome, Jackson-Weiss syndrome) 2782 98 0 0 4 0 0 0 4 4 4 3.5e-06 1 0.31 0.000016 0.018
17 MTMR9 myotubularin related protein 9 1686 163 0 0 3 0 0 0 3 3 1 0.002 0.001 1 0.000028 0.03
18 PPP2R1A protein phosphatase 2 (formerly 2A), regulatory subunit A , alpha isoform 1826 260 0 0 4 0 0 0 4 4 2 0.0021 0.001 0.71 3e-05 0.03
19 U2AF1 U2 small nuclear RNA auxiliary factor 1 824 130 0 0 3 0 0 0 3 3 2 0.00011 0.028 0.16 0.000043 0.041
20 CIZ1 CDKN1A interacting zinc finger protein 1 2761 0 0 0 0 0 0 2 2 2 1 0.00038 0.01 0.82 0.000051 0.047
21 FRG2B FSHD region gene 2 family, member B 850 308 0 0 3 0 0 0 3 3 2 0.00021 0.021 1 0.000058 0.05
22 EEA1 early endosome antigen 1 4348 65 0 0 0 2 0 1 3 3 2 0.00098 0.0059 1 0.000081 0.068
23 PRUNE2 prune homolog 2 (Drosophila) 9339 3 0 0 0 0 0 3 3 3 2 0.0073 0.001 0.99 0.000094 0.075
24 RANBP10 RAN binding protein 10 1915 35 0 0 0 0 0 2 2 2 1 0.0011 0.01 0.089 0.00013 0.1
25 RAD54L2 RAD54-like 2 (S. cerevisiae) 4488 27 0 0 0 0 0 2 2 2 1 0.0013 0.01 0.17 0.00016 0.11
26 HEG1 HEG homolog 1 (zebrafish) 4212 77 0 0 0 0 1 1 2 2 2 0.00018 1 0.078 0.00021 0.14
27 NIPBL Nipped-B homolog (Drosophila) 8642 8 0 0 0 1 1 2 4 4 4 0.000018 1 0.98 0.00022 0.15
28 PARP14 poly (ADP-ribose) polymerase family, member 14 5472 29 0 0 2 1 0 0 3 2 3 0.019 0.002 0.2 0.00023 0.15
29 PM20D1 peptidase M20 domain containing 1 1559 90 0 0 1 0 1 1 3 3 3 0.000039 1 0.4 0.00023 0.15
30 AASDH aminoadipate-semialdehyde dehydrogenase 3353 61 0 0 1 0 0 2 3 3 3 0.0069 0.0027 0.61 0.00024 0.15
31 NPY neuropeptide Y 304 130 0 0 1 0 1 0 2 2 2 0.0022 0.01 0.87 0.00026 0.15
32 MFN1 mitofusin 1 2294 123 0 0 1 0 1 0 2 2 2 0.0034 0.01 0.92 0.00039 0.22
33 PAPOLG poly(A) polymerase gamma 2295 571 0 0 0 0 2 0 2 2 2 0.004 0.01 0.62 0.00045 0.25
34 RAD17 RAD17 homolog (S. pombe) 2121 447 0 0 0 0 0 2 2 2 1 0.0044 0.01 0.18 0.00048 0.26
35 TTLL11 tubulin tyrosine ligase-like family, member 11 2511 216 0 0 0 0 0 2 2 2 1 0.0045 0.01 0.94 0.00049 0.26
CTNNB1

Figure S1.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the CTNNB1 significant gene.

KRAS

Figure S2.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the KRAS significant gene.

PIK3R1

Figure S3.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the PIK3R1 significant gene.

PTEN

Figure S4.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the PTEN significant gene.

TP53

Figure S5.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the TP53 significant gene.

ARID1A

Figure S6.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the ARID1A significant gene.

CTCF

Figure S7.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the CTCF significant gene.

PIK3CA

Figure S8.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the PIK3CA significant gene.

LOR

Figure S9.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the LOR significant gene.

DNHD1

Figure S10.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the DNHD1 significant gene.

ARID5B

Figure S11.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the ARID5B significant gene.

RRAS2

Figure S12.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the RRAS2 significant gene.

IL27

Figure S13.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the IL27 significant gene.

FGFR2

Figure S14.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the FGFR2 significant gene.

PPP2R1A

Figure S15.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the PPP2R1A significant gene.

U2AF1

Figure S16.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the U2AF1 significant gene.

CIZ1

Figure S17.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the CIZ1 significant gene.

EEA1

Figure S18.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the EEA1 significant gene.

PRUNE2

Figure S19.  Get High-res Image This figure depicts the distribution of mutations and mutation types across the PRUNE2 significant gene.

Methods & Data
Methods

MutSig and its evolving algorithms have existed since the youth of clinical sequencing, with early versions used in multiple publications. [1][2][3]

"Three significance metrics [are] calculated for each gene, using the […] methods MutSigCV [4], MutSigCL, and MutSigFN [5]. These measure the significance of mutation burden, clustering, and functional impact, respectively […]. MutSigCV determines the P value for observing the given quantity of non-silent mutations in the gene, given the background model determined by silent (and noncoding) mutations in the same gene and the neighbouring genes of covariate space that form its 'bagel'. […] MutSigCL and MutSigFN measure the significance of the positional clustering of the mutations observed, as well as the significance of the tendency for mutations to occur at positions that are highly evolutionarily conserved (using conservation as a proxy for probably functional impact). MutSigCL and MutSigFN are permutation-based methods and their P values are calculated as follows: The observed nonsilent coding mutations in the gene are permuted T times (to simulate the null hypothesis, T = 108 for the most significant genes), randomly reassigning their positions, but preserving their mutational 'category', as determined by local sequence context. We [use] the following context categories: transitions at CpG dinucleotides, transitions at other C-G base pairs, transversions at C-G base pairs, mutations at A-T base pairs, and indels. Indels are unconstrained in terms of where they can move to in the permutations. For each of the random permutations, two scores are calculated: SCL and SFN, measuring the amount of clustering and function impact (measured by conservation) respectively. SCL is defined to be the fraction of mutations occurring in hotspots. A hotspot is defined as a 3-base-pair region of the gene containing many mutations: at least 2, and at least 2% of the total mutations. SFN is defined to be the mean of the base-pair-level conservation values for the position of each non-silent mutation […]. To determine a PCL, the P value for the observed degree of positional clustering, the observed value of SCL (computed for the mutations actually observed), [is] compared to the distribution of SCL obtained from the random permutations, and the P value [is] defined to be the fraction of random permutations in which SCL [is] at least as large as the observed SCL. The P value for the conservation of the mutated positions, PFN, [is] computed analogously." [6]

References
[1] Getz G, Höfling H, Mesirov JP, Golub TR, Meyerson M, Tibshirani R, Lander ES, Comment on "The Consensus Coding Sequences of Human Breast and Colorectal Cancers", Science 317(5844):1500b (2007)
[3] TCGA, Integrated genomic analyses of ovarian carcinoma, Nature 474(7353):609-615 (2011)
[4] Lawrence MS, et al., Mutational heterogeneity in cancer and the search for new cancer-associated genes, Nature 499(7457):214-218 (2013)
[6] Lawrence MS, et al., Discovery and saturation analysis of cancer genes across 21 tumour types, Nature 505(7484):495-501 (2014)