Hallmarks of germline BRCA1/2-associated ovarian carcinomas include chemosensitivity and improved survival. The therapeutic impact of somatic BRCA1/2 mutations and mutations in other homologous ...recombination DNA repair genes is uncertain.
Using targeted capture and massively parallel genomic sequencing, we assessed 390 ovarian carcinomas for germline and somatic loss-of-function mutations in 30 genes, including BRCA1, BRCA2, and 11 other genes in the homologous recombination pathway.
Thirty-one percent of ovarian carcinomas had a deleterious germline (24%) and/or somatic (9%) mutation in one or more of the 13 homologous recombination genes: BRCA1, BRCA2, ATM, BARD1, BRIP1, CHEK1, CHEK2, FAM175A, MRE11A, NBN, PALB2, RAD51C, and RAD51D. Nonserous ovarian carcinomas had similar rates of homologous recombination mutations to serous carcinomas (28% vs. 31%, P = 0.6), including clear cell, endometrioid, and carcinosarcoma. The presence of germline and somatic homologous recombination mutations was highly predictive of primary platinum sensitivity (P = 0.0002) and improved overall survival (P = 0.0006), with a median overall survival of 66 months in germline homologous recombination mutation carriers, 59 months in cases with a somatic homologous recombination mutation, and 41 months for cases without a homologous recombination mutation.
Germline or somatic mutations in homologous recombination genes are present in almost one third of ovarian carcinomas, including both serous and nonserous histologies. Somatic BRCA1/2 mutations and mutations in other homologous recombination genes have a similar positive impact on overall survival and platinum responsiveness as germline BRCA1/2 mutations. The similar rate of homologous recombination mutations in nonserous carcinomas supports their inclusion in PARP inhibitor clinical trials.
Inherited loss-of-function mutations in BRCA1 and BRCA2 and other tumor suppressor genes predispose to ovarian carcinomas, but the overall burden of disease due to inherited mutations is not known. ...Using targeted capture and massively parallel genomic sequencing, we screened for germ-line mutations in 21 tumor suppressor genes in genomic DNA from women with primary ovarian, peritoneal, or fallopian tube carcinoma. Subjects were consecutively enrolled at diagnosis and not selected for age or family history. All classes of mutations, including point mutations and large genomic deletions and insertions, were detected. Of 360 subjects, 24% carried germ-line loss-of-function mutations: 18% in BRCA1 or BRCA2 and 6% in BARD1, BRIP1, CHEK2, MRE11A, MSH6, NBN, PALB2, RAD50, RAD51C, or TP53. Six of these genes were not previously implicated in inherited ovarian carcinoma. Primary carcinomas were generally characterized by genomic loss of normal alleles of the mutant genes. Of women with inherited mutations, >30% had no family history of breast or ovarian carcinoma, and >35% were 60 y or older at diagnosis. More patients with ovarian carcinoma carry cancer-predisposing mutations and in more genes than previously appreciated. Comprehensive genetic testing for inherited carcinoma is warranted for all women with ovarian, peritoneal, or fallopian tube carcinoma, regardless of age or family history. Clinical genetic testing is currently done gene by gene, with each test costing thousands of dollars. In contrast, massively parallel sequencing allows such testing for many genes simultaneously at low cost.
We hypothesized that mutations in homologous recombination repair (HRR) genes beyond
and
improve outcomes for ovarian carcinoma patients treated with platinum therapy and would impact the relative ...benefit of adding prolonged bevacizumab.
We sequenced DNA from blood and/or neoplasm from 1,195 women enrolled in GOG-0218, a randomized phase III trial in advanced ovarian carcinoma of bevacizumab added to carboplatin and paclitaxel. Defects in HRR were defined as damaging mutations in 16 genes. Proportional hazards models were used to estimate relative hazards for progression-free survival (PFS) and overall survival (OS).
Of 1,195 women with ovarian carcinoma, HRR mutations were identified in 307 (25.7%). Adjusted hazards for progression and death compared with those without mutations were lower for women with non-
HRR mutations HR = 0.73; 95% confidence interval (CI), 0.57-0.94;
= 0.01 for PFS; HR = 0.67; 95% CI, 0.50-0.90;
= 0.007 for OS and
mutations (HR = 0.80; 95% CI, 0.66-0.97;
= 0.02 for PFS; HR = 0.74; 95% CI, 0.59-0.94;
= 0.01 for OS) and were lowest for
mutations (HR = 0.52; 95% CI, 0.40-0.67;
< 0.0001 for PFS; HR = 0.36; 95% CI, 0.25-0.53;
< 0.0001 for OS). A test of interaction showed no difference in the effect of bevacizumab on PFS between cases with and without mutations.
HRR mutations, including non-
genes, significantly prolong PFS and OS in ovarian carcinoma and should be stratified for in clinical trials. The benefit of adding bevacizumab was not significantly modified by mutation status.
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Inherited loss-of-function mutations in the tumor suppressor genes BRCA1, BRCA2, and multiple other genes predispose to high risks of breast and/or ovarian cancer. Cancer-associated inherited ...mutations in these genes are collectively quite common, but individually rare or even private. Genetic testing for BRCA1 and BRCA2 mutations has become an integral part of clinical practice, but testing is generally limited to these two genes and to women with severe family histories of breast or ovarian cancer. To determine whether massively parallel, "next-generation" sequencing would enable accurate, thorough, and cost-effective identification of inherited mutations for breast and ovarian cancer, we developed a genomic assay to capture, sequence, and detect all mutations in 21 genes, including BRCA1 and BRCA2, with inherited mutations that predispose to breast or ovarian cancer. Constitutional genomic DNA from subjects with known inherited mutations, ranging in size from 1 to >100,000 bp, was hybridized to custom oligonucleotides and then sequenced using a genome analyzer. Analysis was carried out blind to the mutation in each sample. Average coverage was >1200 reads per base pair. After filtering sequences for quality and number of reads, all single-nucleotide substitutions, small insertion and deletion mutations, and large genomic duplications and deletions were detected. There were zero false-positive calls of nonsense mutations, frameshift mutations, or genomic rearrangements for any gene in any of the test samples. This approach enables widespread genetic testing and personalized risk assessment for breast and ovarian cancer.
Inherited mutations in the BRCA2-interacting protein PALB2 are known to be associated with increased risks of developing breast cancer. To evaluate the contribution of PALB2 to familial breast cancer ...in the United States, we sequenced the coding sequences and flanking regulatory regions of the gene from constitutional genomic DNA of 1,144 familial breast cancer patients with wild-type sequences at BRCA1 and BRCA2. Overall, 3.4% (33/972) of patients not selected by ancestry and 0% (0/172) of patients specifically of Ashkenazi Jewish ancestry were heterozygous for a nonsense, frameshift, or frameshift-associated splice mutation in PALB2. Mutations were detected in both male and female breast cancer patients. All mutations were individually rare: the 33 heterozygotes harbored 13 different mutations, 5 previously reported and 8 novel mutations. PALB2 heterozygotes were 4-fold more likely to have a male relative with breast cancer (P = 0.0003), 6-fold more likely to have a relative with pancreatic cancer (P = 0.002), and 1.3-fold more likely to have a relative with ovarian cancer (P = 0.18). Compared with their female relatives without mutations, increased risk of developing breast cancer for female PALB2 heterozygotes was 2.3-fold (95% CI: 1.5-4.2) by age 55 and 3.4-fold (95% CI: 2.4-5.9) by age 85. Loss of the wild-type PALB2 allele was observed in laser-dissected tumor specimens from heterozygous patients. Given this mutation prevalence and risk, consideration might be given to clinical testing of PALB2 by complete genomic sequencing for familial breast cancer patients with wild-type sequences at BRCA1 and BRCA2.
Most patients with childhood-onset immune dysregulation, polyendocrinopathy, and enteropathy have no genetic diagnosis for their illness. These patients may undergo empirical immunosuppressive ...treatment with highly variable outcomes.
We sought to determine the genetic basis of disease in patients referred with Immune dysregulation, polyendocrinopathy, enteropathy, X-linked–like (IPEX-like) disease, but with no mutation in FOXP3; then to assess consequences of genetic diagnoses for clinical management.
Genomic DNA was sequenced using a panel of 462 genes implicated in inborn errors of immunity. Candidate mutations were characterized by genomic, transcriptional, and (for some) protein analysis.
Of 123 patients with FOXP3-negative IPEX-like disease, 48 (39%) carried damaging germline mutations in 1 of the following 27 genes: AIRE, BACH2, BCL11B, CARD11, CARD14, CTLA4, IRF2BP2, ITCH, JAK1, KMT2D, LRBA, MYO5B, NFKB1, NLRC4, POLA1, POMP, RAG1, SH2D1A, SKIV2L, STAT1, STAT3, TNFAIP3, TNFRSF6/FAS, TNRSF13B/TACI, TOM1, TTC37, and XIAP. Many of these genes had not been previously associated with an IPEX-like diagnosis. For 42 of the 48 patients with genetic diagnoses, knowing the critical gene could have altered therapeutic management, including recommendations for targeted treatments and for or against hematopoietic cell transplantation.
Many childhood disorders now bundled as “IPEX-like” disease are caused by individually rare, severe mutations in immune regulation genes. Most genetic diagnoses of these conditions yield clinically actionable findings. Barriers are lack of testing or lack of repeat testing if older technologies failed to provide a diagnosis.
The genetic characterization of a common phenotype for an entire population reveals both the causes of that phenotype for that place and the power of family-based, population-wide genomic analysis ...for gene and mutation discovery. We characterized the genetics of hearing loss throughout the Palestinian population, enrolling 2,198 participants from 491 families from all parts of the West Bank and Gaza. In Palestinian families with no prior history of hearing loss, we estimate that 56% of hearing loss is genetic and 44% is not genetic. For the great majority (87%) of families with inherited hearing loss, panel-based genomic DNA sequencing, followed by segregation analysis of large kindreds and transcriptional analysis of participant RNA, enabled identification of the causal genes and mutations, including at distant noncoding sites. Genetic heterogeneity of hearing loss was striking with respect to both genes and alleles: The 337 solved families harbored 143 different mutations in 48 different genes. For one in four solved families, a transcription-altering mutation was the responsible allele. Many of these mutations were cryptic, either exonic alterations of splice enhancers or silencers or deeply intronic events. Experimentally calibrated in silico analysis of transcriptional effects yielded inferences of high confidence for effects on splicing even of mutations in genes not expressed in accessible tissue. Most (58%) of all hearing loss in the population was attributable to consanguinity. Given the ongoing decline in consanguineous marriage, inherited hearing loss will likely be much rarer in the next generation.
CONTEXT Genetic testing for inherited mutations in BRCA1 and BRCA2 has become integral to the care of women with a severe family history of breast or ovarian cancer, but an unknown number of patients ...receive negative (ie, wild-type) results when they actually carry a pathogenic BRCA1 or BRCA2 mutation. Furthermore, other breast cancer genes generally are not evaluated. OBJECTIVE To determine the frequency and types of undetected cancer-predisposing mutations in BRCA1, BRCA2, CHEK2, TP53, and PTEN among patients with breast cancer from high-risk families with negative (wild-type) genetic test results for BRCA1 and BRCA2. DESIGN, SETTING, AND PARTICIPANTS Between 2002-2005, probands from 300 US families with 4 or more cases of breast or ovarian cancer but with negative (wild-type) commercial genetic test results for BRCA1 and BRCA2 were screened by multiple DNA-based and RNA-based methods to detect genomic rearrangements in BRCA1 and BRCA2 and germline mutations of all classes in CHEK2, TP53, and PTEN. MAIN OUTCOME MEASURES Previously undetected germline mutations in BRCA1, BRCA2, CHEK2, TP53, and PTEN that predispose to breast cancer; frequencies of these mutations among families with negative genetic test results. RESULTS Of the 300 probands, 52 (17%) carried previously undetected mutations, including 35 (12%) with genomic rearrangements of BRCA1 or BRCA2, 14 (5%) with CHEK2 mutations, and 3 (1%) with TP53 mutations. At BRCA1 and BRCA2, 22 different genomic rearrangements were found, of sizes less than 1 kb to greater than 170 kb; of these, 14 were not previously described and all were individually rare. At CHEK2, a novel 5.6-kb genomic deletion was discovered in 2 families of Czechoslovakian ancestry. This deletion was found in 8 of 631 (1.3%) patients with breast cancer and in none of 367 healthy controls in the Czech and Slovak Republics. For all rearrangements, exact genomic breakpoints were determined and diagnostic primers validated. The 3 families with TP53 mutations included cases of childhood sarcoma or brain tumors in addition to multiple cases of breast cancer. CONCLUSIONS The mutational spectra of BRCA1 and BRCA2 include many high-penetrance, individually rare genomic rearrangements. Among patients with breast cancer and severe family histories of cancer who test negative (wild type) for BRCA1 and BRCA2, approximately 12% can be expected to carry a large genomic deletion or duplication in one of these genes, and approximately 5% can be expected to carry a mutation in CHEK2 or TP53. Effective methods for identifying these mutations should be made available to women at high risk.
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