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2.
Clin Genet ; 98(4): 374-378, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32627184

RESUMO

We present two independent cases of syndromic thrombocytopenia with multiple malformations, microcephaly, learning difficulties, dysmorphism and other features. Exome sequencing identified two novel de novo heterozygous variants in these patients, c.35G>T p.(Gly12Val) and c.178G>C p.(Gly60Arg), in the RAP1B gene (NM_001010942.2). These variants have not been described previously as germline variants, however functional studies in literature strongly suggest a clinical implication of these two activating hot spot positions. We hypothesize that pathogenic missense variants in the RAP1B gene cause congenital syndromic thrombocytopenia with a spectrum of associated malformations and dysmorphism, possibly through a gain of function mechanism.

3.
Hum Genet ; 139(11): 1443-1454, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32514796

RESUMO

Dilated cardiomyopathy (DCM) belongs to the most frequent forms of cardiomyopathy mainly characterized by cardiac dilatation and reduced systolic function. Although most cases of DCM are classified as sporadic, 20-30% of cases show a heritable pattern. Familial forms of DCM are genetically heterogeneous, and mutations in several genes have been identified that most commonly play a role in cytoskeleton and sarcomere-associated processes. Still, a large number of familial cases remain unsolved. Here, we report five individuals from three independent families who presented with severe dilated cardiomyopathy during the neonatal period. Using whole-exome sequencing (WES), we identified causative, compound heterozygous missense variants in RPL3L (ribosomal protein L3-like) in all the affected individuals. The identified variants co-segregated with the disease in each of the three families and were absent or very rare in the human population, in line with an autosomal recessive inheritance pattern. They are located within the conserved RPL3 domain of the protein and were classified as deleterious by several in silico prediction software applications. RPL3L is one of the four non-canonical riboprotein genes and it encodes the 60S ribosomal protein L3-like protein that is highly expressed only in cardiac and skeletal muscle. Three-dimensional homology modeling and in silico analysis of the affected residues in RPL3L indicate that the identified changes specifically alter the interaction of RPL3L with the RNA components of the 60S ribosomal subunit and thus destabilize its binding to the 60S subunit. In conclusion, we report that bi-allelic pathogenic variants in RPL3L are causative of an early-onset, severe neonatal form of dilated cardiomyopathy, and we show for the first time that cytoplasmic ribosomal proteins are involved in the pathogenesis of non-syndromic cardiomyopathies.


Assuntos
Cardiomiopatia Dilatada/genética , Mutação de Sentido Incorreto/genética , Proteínas Ribossômicas/genética , Ribossomos/genética , Alelos , Exoma/genética , Feminino , Coração/fisiopatologia , Humanos , Lactente , Recém-Nascido , Masculino , Músculo Esquelético/fisiopatologia , Linhagem , Fenótipo , RNA/genética
4.
J Neurol ; 267(9): 2732-2743, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32447552

RESUMO

Amyotrophic lateral sclerosis (ALS) and hereditary spastic paraplegia (HSP) are motor neuron diseases sharing clinical, pathological, and genetic similarities. While biallelic SPG7 mutations are known to cause recessively inherited HSP, heterozygous SPG7 mutations have repeatedly been identified in HSP and recently also in ALS cases. However, the frequency and clinical impact of rare SPG7 variants have not been studied in a larger ALS cohort. Here, whole-exome (WES) or targeted SPG7 sequencing was done in a cohort of 214 European ALS patients. The consequences of a splice site variant were analyzed on the mRNA level. The resulting protein alterations were visualized in a crystal structure model. All patients were subjected to clinical, electrophysiological, and neuroradiological characterization. In 9 of 214 (4.2%) ALS cases, we identified five different rare heterozygous SPG7 variants, all of which were previously reported in patients with HSP or ALS. All detected SPG7 variants affect the AAA+ domain of the encoded mitochondrial metalloprotease paraplegin and impair its stability or function according to predictions from mRNA analysis or crystal structure modeling. ALS patients with SPG7 mutations more frequently presented with cerebellar symptoms, flail arm or leg syndrome compared to those without SPG7 mutations, and showed a partial clinical overlap with HSP. Brain MRI findings in SPG7 mutation carriers included cerebellar atrophy and patterns suggestive of frontotemporal dementia. Collectively, our findings suggest that SPG7 acts as a genetic risk factor for ALS. ALS patients carrying SPG7 mutations present with distinct features overlapping with HSP, particularly regarding cerebellar findings.

5.
J Natl Cancer Inst ; 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32107557

RESUMO

BACKGROUND: The purpose of this study was to estimate precise age-specific tubo-ovarian carcinoma (TOC) and breast cancer (BC) risks for carriers of pathogenic variants in RAD51C and RAD51D. METHODS: We analysed data from 6178 families, 125 with pathogenic variants in RAD51C; and 6690 families, 60 with pathogenic variants in RAD51D. TOC and BC relative and cumulative risks were estimated using complex segregation analysis to model the cancer inheritance patterns in families, while adjusting for the mode of ascertainment of each family. All statistical tests were two-sided. RESULTS: Pathogenic variants in both RAD51C and RAD51D were associated with TOC (RAD51C RR = 7.55, 95%CI:5.60-10.19, p = 5 × 10-40; RAD51D RR = 7.60, 95%CI:5.61-10.30, p = 5 × 10-39) and BC (RAD51C RR = 1.99, 95%CI:1.39-2.85, p = 1.55 × 10-4; RAD51D RR = 1.83, 95%CI:1.24-2.72, p = 0.002). For both RAD51C and RAD51D, there was a suggestion that the TOC RRs increased with age until around age 60 years and decreased thereafter. The estimated cumulative risks of developing TOC to age 80 were 11% (95%CI:6-21%) for RAD51C and 13% (95%CI:7-23%) for RAD51D pathogenic variant carriers. The estimated cumulative risks of developing BC to 80 were 21% (95%CI:15-29%) for RAD51C and 20% (95%CI:14-28%) for RAD51D pathogenic variant carriers. Both TOC and BC risks for RAD51C/D pathogenic variant carriers varied by cancer family history, and could be as high as 32-36% for TOC, for carriers with two first degree relatives diagnosed with TOC; or 44-46% for BC, for carriers with two first degree relatives diagnosed with BC. CONCLUSIONS: These estimates will facilitate the genetic counselling of RAD51C and RAD51D pathogenic variant carriers and justify the incorporation of RAD51C and RAD51D into cancer risk prediction models.

6.
Stem Cell Res ; 43: 101713, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32000109

RESUMO

Chronic mucocutaneous candidiasis (CMC) is a disease that is characterized by susceptibility to chronic or recurrent infections with Candida spp. due to mutations affecting mainly the IL-17 signaling of T-Cells. The most common etiologies of CMC are gain-of-function (GOF) mutations in the STAT1 gene. In this paper we report the generation of a hiPSC line from a patient suffering from CMC due to a heterozygous GOF STAT1 p.R274Q mutation which can be used for disease modeling purposes.

7.
Nat Genet ; 52(1): 56-73, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31911677

RESUMO

Genome-wide association studies have identified breast cancer risk variants in over 150 genomic regions, but the mechanisms underlying risk remain largely unknown. These regions were explored by combining association analysis with in silico genomic feature annotations. We defined 205 independent risk-associated signals with the set of credible causal variants in each one. In parallel, we used a Bayesian approach (PAINTOR) that combines genetic association, linkage disequilibrium and enriched genomic features to determine variants with high posterior probabilities of being causal. Potentially causal variants were significantly over-represented in active gene regulatory regions and transcription factor binding sites. We applied our INQUSIT pipeline for prioritizing genes as targets of those potentially causal variants, using gene expression (expression quantitative trait loci), chromatin interaction and functional annotations. Known cancer drivers, transcription factors and genes in the developmental, apoptosis, immune system and DNA integrity checkpoint gene ontology pathways were over-represented among the highest-confidence target genes.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Mapeamento Cromossômico/métodos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Teorema de Bayes , Feminino , Humanos , Desequilíbrio de Ligação , Sequências Reguladoras de Ácido Nucleico , Fatores de Risco
8.
Cancer Res ; 80(3): 624-638, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31723001

RESUMO

Pathogenic sequence variants (PSV) in BRCA1 or BRCA2 (BRCA1/2) are associated with increased risk and severity of prostate cancer. We evaluated whether PSVs in BRCA1/2 were associated with risk of overall prostate cancer or high grade (Gleason 8+) prostate cancer using an international sample of 65 BRCA1 and 171 BRCA2 male PSV carriers with prostate cancer, and 3,388 BRCA1 and 2,880 BRCA2 male PSV carriers without prostate cancer. PSVs in the 3' region of BRCA2 (c.7914+) were significantly associated with elevated risk of prostate cancer compared with reference bin c.1001-c.7913 [HR = 1.78; 95% confidence interval (CI), 1.25-2.52; P = 0.001], as well as elevated risk of Gleason 8+ prostate cancer (HR = 3.11; 95% CI, 1.63-5.95; P = 0.001). c.756-c.1000 was also associated with elevated prostate cancer risk (HR = 2.83; 95% CI, 1.71-4.68; P = 0.00004) and elevated risk of Gleason 8+ prostate cancer (HR = 4.95; 95% CI, 2.12-11.54; P = 0.0002). No genotype-phenotype associations were detected for PSVs in BRCA1. These results demonstrate that specific BRCA2 PSVs may be associated with elevated risk of developing aggressive prostate cancer. SIGNIFICANCE: Aggressive prostate cancer risk in BRCA2 mutation carriers may vary according to the specific BRCA2 mutation inherited by the at-risk individual.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Predisposição Genética para Doença , Genômica/métodos , Mutação , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Associação Genética , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Adulto Jovem
9.
Mol Genet Genomic Med ; 8(9): e1045, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31724318

RESUMO

BACKGROUND: Germline mutations in BRCA1/2 significantly contribute to hereditary breast and/or ovarian cancer. Here, we report a novel BRCA2 duplication of exons 22-24 in a female patient with bilateral breast cancer at age 35 and 44. The duplicated region was initially detected by gene panel sequencing and multiplex ligation-dependent probe amplification. However, the location and orientation of the duplicated region was unknown. Therefore, it was initially classified as a variant of unknown significance. METHODS: The spatial directional characterization of the BRCA2 duplication was achieved by targeted enrichment of the whole-genomic BRCA2 locus including exons and introns, and subsequent high-throughput sequencing. Subsequently, bioinformatics tools and a breakpoint-spanning PCR were used for identification of location and orientation of the duplication. RESULTS: The duplicated region was arranged in tandem and direct orientation (Chr13(GRCh37):g.32951579_32960394dup; NM_000059.3 c.8754 + 651_9256+6112dup p.(Ala3088Phefs*3)). It is predicted to result in a frameshift and a premature stop codon likely triggering nonsense-mediated mRNA decay. Consequently, it is regarded as pathogenic. CONCLUSION: This case study demonstrates that a comprehensive characterization of a structural variant by breakpoint assessment is crucial for its correct classification. Therefore, sequencing strategies including non-coding regions might be necessary to identify cancer predispositions in affected families.

10.
NPJ Breast Cancer ; 5: 38, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31700994

RESUMO

Breast cancer is a common disease partially caused by genetic risk factors. Germline pathogenic variants in DNA repair genes BRCA1, BRCA2, PALB2, ATM, and CHEK2 are associated with breast cancer risk. FANCM, which encodes for a DNA translocase, has been proposed as a breast cancer predisposition gene, with greater effects for the ER-negative and triple-negative breast cancer (TNBC) subtypes. We tested the three recurrent protein-truncating variants FANCM:p.Arg658*, p.Gln1701*, and p.Arg1931* for association with breast cancer risk in 67,112 cases, 53,766 controls, and 26,662 carriers of pathogenic variants of BRCA1 or BRCA2. These three variants were also studied functionally by measuring survival and chromosome fragility in FANCM -/- patient-derived immortalized fibroblasts treated with diepoxybutane or olaparib. We observed that FANCM:p.Arg658* was associated with increased risk of ER-negative disease and TNBC (OR = 2.44, P = 0.034 and OR = 3.79; P = 0.009, respectively). In a country-restricted analysis, we confirmed the associations detected for FANCM:p.Arg658* and found that also FANCM:p.Arg1931* was associated with ER-negative breast cancer risk (OR = 1.96; P = 0.006). The functional results indicated that all three variants were deleterious affecting cell survival and chromosome stability with FANCM:p.Arg658* causing more severe phenotypes. In conclusion, we confirmed that the two rare FANCM deleterious variants p.Arg658* and p.Arg1931* are risk factors for ER-negative and TNBC subtypes. Overall our data suggest that the effect of truncating variants on breast cancer risk may depend on their position in the gene. Cell sensitivity to olaparib exposure, identifies a possible therapeutic option to treat FANCM-associated tumors.

11.
Am J Nephrol ; 50(4): 281-290, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31473739

RESUMO

BACKGROUND: Tolvaptan can slow down renal function decline in autosomal dominant polycystic kidney disease (-ADPKD). While there is consensus across international recommendations that the drug should only be used in patients with high risk of rapid progression, identification criteria for rapid progression vary. Here, we investigated different assessment strategies using a real-life ADPKD cohort. METHODS: Observational retrospective cohort analysis. The study included 131 ADPKD patients aged 19-78 years who were referred to the Hannover Medical School outpatient clinic for evaluation of tolvaptan treatment. Six different assessment strategies for tolvaptan eligibility were tested for each patient. Comparative analysis for different assessments was performed in the total study population, the subpopulation with available computed tomography/magnetic resonance imaging data, and the genotyped subpopulation. RESULTS: Comparing 6 assessment strategies revealed strong variations in the individual selection processes resulting in treatment recommendations for 14.5-64.9% of patients. The highest patient number was selected by the Scottish and the lowest by the Japanese approach. Few patients had positive recommendations by all 6 systems, but strong congruency was observed between the Scottish, U.K. and Canadian patient selection. The lowest number of overlapping patients was found between the Japanese and the ERA-EDTA selection. Important discrepancies were also found between the ERA-EDTA and the U.S. system due to different emphases on parameters of kidney function versus kidney volume. Limitations of the study included the restricted sample size, heterogeneity in parameter availability and lack of outcome data. CONCLUSIONS: The study draws attention to important discrepancies between different decision algorithms for tolvaptan eligibility in ADPKD patients.


Assuntos
Seleção de Pacientes , Rim Policístico Autossômico Dominante/tratamento farmacológico , Tolvaptan/uso terapêutico , Adulto , Idoso , Algoritmos , Progressão da Doença , Feminino , Genótipo , Alemanha/epidemiologia , Taxa de Filtração Glomerular , Humanos , Testes de Função Renal , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Nefrologia/normas , Rim Policístico Autossômico Dominante/fisiopatologia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Adulto Jovem
12.
BMC Cancer ; 19(1): 787, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31395037

RESUMO

BACKGROUND: Inherited pathogenic variants in BRCA1 and BRCA2 are the most common causes of hereditary breast and ovarian cancer (HBOC). The risk of developing breast cancer by age 80 in women carrying a BRCA1 pathogenic variant is 72%. The lifetime risk varies between families and even within affected individuals of the same family. The cause of this variability is largely unknown, but it is hypothesized that additional genetic factors contribute to differences in age at onset (AAO). Here we investigated whether truncating and rare missense variants in genes of different DNA-repair pathways contribute to this phenomenon. METHODS: We used extreme phenotype sampling to recruit 133 BRCA1-positive patients with either early breast cancer onset, below 35 (early AAO cohort) or cancer-free by age 60 (controls). Next Generation Sequencing (NGS) was used to screen for variants in 311 genes involved in different DNA-repair pathways. RESULTS: Patients with an early AAO (73 women) had developed breast cancer at a median age of 27 years (interquartile range (IQR); 25.00-27.00 years). A total of 3703 variants were detected in all patients and 43 of those (1.2%) were truncating variants. The truncating variants were found in 26 women of the early AAO group (35.6%; 95%-CI 24.7 - 47.7%) compared to 16 women of controls (26.7%; 95%-CI 16.1 to 39.7%). When adjusted for environmental factors and family history, the odds ratio indicated an increased breast cancer risk for those carrying an additional truncating DNA-repair variant to BRCA1 mutation (OR: 3.1; 95%-CI 0.92 to 11.5; p-value = 0.07), although it did not reach the conventionally acceptable significance level of 0.05. CONCLUSIONS: To our knowledge this is the first time that the combined effect of truncating variants in DNA-repair genes on AAO in patients with hereditary breast cancer is investigated. Our results indicate that co-occurring truncating variants might be associated with an earlier onset of breast cancer in BRCA1-positive patients. Larger cohorts are needed to confirm these results.


Assuntos
Proteína BRCA1/genética , Biomarcadores Tumorais , Neoplasias da Mama/genética , Reparo do DNA , Predisposição Genética para Doença , Deleção de Sequência , Adulto , Idade de Início , Idoso , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Bases de Dados Genéticas , Feminino , Estudos de Associação Genética , Loci Gênicos , Alemanha/epidemiologia , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Vigilância da População , Medição de Risco , Fatores de Risco
13.
Hum Mutat ; 40(9): 1557-1578, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31131967

RESUMO

The multifactorial likelihood analysis method has demonstrated utility for quantitative assessment of variant pathogenicity for multiple cancer syndrome genes. Independent data types currently incorporated in the model for assessing BRCA1 and BRCA2 variants include clinically calibrated prior probability of pathogenicity based on variant location and bioinformatic prediction of variant effect, co-segregation, family cancer history profile, co-occurrence with a pathogenic variant in the same gene, breast tumor pathology, and case-control information. Research and clinical data for multifactorial likelihood analysis were collated for 1,395 BRCA1/2 predominantly intronic and missense variants, enabling classification based on posterior probability of pathogenicity for 734 variants: 447 variants were classified as (likely) benign, and 94 as (likely) pathogenic; and 248 classifications were new or considerably altered relative to ClinVar submissions. Classifications were compared with information not yet included in the likelihood model, and evidence strengths aligned to those recommended for ACMG/AMP classification codes. Altered mRNA splicing or function relative to known nonpathogenic variant controls were moderately to strongly predictive of variant pathogenicity. Variant absence in population datasets provided supporting evidence for variant pathogenicity. These findings have direct relevance for BRCA1 and BRCA2 variant evaluation, and justify the need for gene-specific calibration of evidence types used for variant classification.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Biologia Computacional/métodos , Mutação de Sentido Incorreto , Neoplasias/diagnóstico , Processamento Alternativo , Detecção Precoce de Câncer , Feminino , Predisposição Genética para Doença , Humanos , Funções Verossimilhança , Masculino , Herança Multifatorial , Neoplasias/genética
14.
Am J Med Genet A ; 179(7): 1383-1389, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31062505

RESUMO

The PTEN hamartoma tumor syndrome (PHTS) is caused by heterozygous germline variants in PTEN. Here, we report two unrelated patients with juvenile polyposis, macrocephaly, intellectual disability, and hyperpigmented skin macules. Both patients were clinically suspected for the Bannayan-Riley-Ruvalcaba syndrome (BRRS), a PHTS subentity. By array-CGH analysis, we identified an interstitial 10q23.1q23.3 deletion in a buccal mucosa sample of Patient 1 that encompassed PTEN, BMPR1A, and KLLN, among others. In contrast, neither sequencing nor array-CGH analysis identified a pathogenic variant in PTEN or BMPR1A in a blood sample of Patient 2. However, in a surgical specimen of the thyroid gland high-level mosaicism for a 10q23.2q23.3 deletion was observed. Additionally, the pathogenic PTEN variant c.956_959delCTTT p.(Thr319LysfsTer24) was detected in his thyroid tissue. The frame shift variant was neither detected in the patient's blood nor in his buccal mucosa sample. Low-level mosaicism for the microdeletion was identified in a buccal swap sample, and reanalysis of the blood sample suggested marginal-level mosaicism for deletion. The 10q23.2q23.3 deletion mosaicism was also identified in a subsequently resected colonic polyp. Thus, in both cases, the diagnosis of a 10q23 deletion syndrome, which clinically presented as BRRS, was established. Overall, the study expands the BRRS spectrum and highlights the relevance of considering mosaicism in PHTS. We conclude that in all patients with a clear clinical suspicion of PHTS, in which genetic analyses of DNA from blood and buccal swap samples fail to identify causative genetic variants, genetic analyses of additional tissues are recommended.


Assuntos
Receptores de Proteínas Morfogenéticas Ósseas Tipo I/genética , Deleção Cromossômica , Cromossomos Humanos Par 10 , Síndrome do Hamartoma Múltiplo/genética , Mosaicismo , Mutação , PTEN Fosfo-Hidrolase/genética , Adolescente , Feminino , Humanos , Masculino
15.
Eur J Hum Genet ; 27(6): 879-887, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30723317

RESUMO

Wilson disease (WD) is an autosomal recessive disease of copper excess due to pathogenic variants in the ATP7B gene coding for a copper-transporting ATPase. We present a 5-year-old girl with the homozygous frame shift variant NM_000053.3: c.19_20del in exon 1 of ATP7B (consecutive exon numbering with c.1 as first nucleotide of exon 1), detected by whole-exome sequencing as a secondary finding. The variant leads to a premature termination codon in exon 2. The girl exhibited no WD symptoms and no abnormalities in liver biopsy. ATP7B liver mRNA expression was comparable to healthy controls suggesting that nonsense-mediated mRNA decay (NMD) could be bypassed by the mechanism of translation reinitiation. To verify this hypothesis, a CMV-driven ATP7B minigene (pcDNA3) was equipped with the authentic ATP7B 5' untranslated region  and a truncated intron 2. We introduced c.19_20del by site-directed mutagenesis and overexpressed the constructs in HEK293T cells. We analyzed ATP7B expression by qRT-PCR, northern and western blot, and examined protein function by copper export capacity assays. Northern blot, qRT-PCR, and western blot revealed that c.19_20del ATP7B mRNA and protein is expressed in size and amount comparable to wild-type. Copper export capacity was also comparable to wild-type. Our results indicate that c.19_20del in ATP7B is able to bypass NMD by translation reinitiation, demonstrating that the classification of truncating variants as pathogenic without additional investigations should be done carefully.


Assuntos
ATPases Transportadoras de Cobre , Cobre/metabolismo , Éxons , Mutação da Fase de Leitura , Degeneração Hepatolenticular , Homozigoto , Degradação do RNAm Mediada por Códon sem Sentido , Pré-Escolar , ATPases Transportadoras de Cobre/genética , ATPases Transportadoras de Cobre/metabolismo , Feminino , Células HEK293 , Degeneração Hepatolenticular/genética , Degeneração Hepatolenticular/metabolismo , Humanos , Transporte de Íons/genética
16.
Int J Cancer ; 144(11): 2683-2694, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30426508

RESUMO

NGS-based multiple gene panel resequencing in combination with a high resolution CGH-array was used to identify genetic risk factors for hereditary breast and/or ovarian cancer in 237 high risk patients who were previously tested negative for pathogenic BRCA1/2 variants. All patients were screened for pathogenic variants in 94 different cancer predisposing genes. We identified 32 pathogenic variants in 14 different genes (ATM, BLM, BRCA1, CDH1, CHEK2, FANCG, FANCM, FH, HRAS, PALB2, PMS2, PTEN, RAD51C and NBN) in 30 patients (12.7%). Two pathogenic BRCA1 variants that were previously undetected due to less comprehensive and sensitive methods were found. Five pathogenic variants are novel, three of which occur in genes yet unrelated to hereditary breast and/or ovarian cancer (FANCG, FH and HRAS). In our cohort we discovered a remarkably high frequency of truncating variants in FANCM (2.1%), which has recently been suggested as a susceptibility gene for hereditary breast cancer. Two patients of our cohort carried two different pathogenic variants each and 10 other patients in whom a pathogenic variant was confirmed also harbored a variant of unknown significance in a breast and ovarian cancer susceptibility gene. We were able to identify pathogenic variants predisposing for tumor formation in 12.3% of BRCA1/2 negative breast and/or ovarian cancer patients.


Assuntos
Neoplasias da Mama Masculina/genética , Neoplasias da Mama/genética , DNA Helicases/genética , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Neoplasias Ovarianas/genética , Adolescente , Adulto , Idoso , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/patologia , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Testes Genéticos , Humanos , Masculino , Anamnese , Pessoa de Meia-Idade , Adulto Jovem
17.
Breast Cancer Res Treat ; 172(3): 561-569, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30191368

RESUMO

PURPOSE: The purpose of this study is to characterize a novel structural variant, a large duplication involving exons 1-19 of the BRCA1 gene in four independent families, and to provide diagnostically valuable information including the position of the breakpoints as well as clues to its clinical significance. METHODS: The duplication of exons 1-19 of the BRCA1 gene was initially detected by routine laboratory testing including MLPA analysis and next generation sequencing. For detailed characterization we performed array-comparative genome hybridization analysis, fluorescent in situ hybridization, next generation mapping, and long-distance PCR for break-point sequencing. RESULTS: Our data revealed a tandem duplication on chromosome 17 that encompassed 357 kb and included exons 1-19 of the BRCA1 gene and the genes NBR2, NBR1, TMEM106A, LOC100130581, ARL4D, MIR2117 up to parts of the DHX8 gene. This structural variant appeared as a tandem duplication with breakpoints in intron 19 of the BRCA1 gene and in intron 3 of the DHX8 gene (HGVS:chr17(hg19):g.41210776_41568516dup). Segregation analysis indicated that this structural rearrangement is phased in trans with a known pathogenic exon deletion of the BRCA1 gene in one family. CONCLUSIONS: The copy number variation initially recognized as duplication of exon 1-19 of the BRCA1 gene by MLPA analysis is a structural variation with breakpoints in the BRCA1 and DHX8 genes. Although currently to be classified as a variant of unknown significance, our family data indicates that this duplication may be a benign variation or at least of markedly reduced penetrance since it occurs in trans with another known fully pathogenic variant in the BRCA1 gene.


Assuntos
RNA Helicases DEAD-box/genética , Éxons , Duplicação Gênica , Genes BRCA1 , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Fatores de Processamento de RNA/genética , Adulto , Variações do Número de Cópias de DNA , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos
18.
Breast Cancer Res ; 20(1): 87, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-30086788

RESUMO

BACKGROUND: Breast cancer is the most prevalent tumor entity in Li-Fraumeni syndrome. Up to 80% of individuals with a Li-Fraumeni-like phenotype do not harbor detectable causative germline TP53 variants. Yet, no systematic panel analyses for a wide range of cancer predisposition genes have been conducted on cohorts of women with breast cancer fulfilling Li-Fraumeni(-like) clinical diagnostic criteria. METHODS: To specifically help explain the diagnostic gap of TP53 wild-type Li-Fraumeni(-like) breast cancer cases, we performed array-based CGH (comparative genomic hybridization) and panel-based sequencing of 94 cancer predisposition genes on 83 breast cancer patients suggestive of Li-Fraumeni syndrome who had previously had negative test results for causative BRCA1, BRCA2, and TP53 germline variants. RESULTS: We identified 13 pathogenic or likely pathogenic germline variants in ten patients and in nine genes, including four copy number aberrations and nine single-nucleotide variants or small indels. Three patients presented as double-mutation carriers involving two different genes each. In five patients (5 of 83; 6% of cohort), we detected causative pathogenic variants in established hereditary breast cancer susceptibility genes (i.e., PALB2, CHEK2, ATM). Five further patients (5 of 83; 6% of cohort) were found to harbor pathogenic variants in genes lacking a firm association with breast cancer susceptibility to date (i.e., Fanconi pathway genes, RECQ family genes, CDKN2A/p14ARF, and RUNX1). CONCLUSIONS: Our study details the mutational spectrum in breast cancer patients suggestive of Li-Fraumeni syndrome and indicates the need for intensified research on monoallelic variants in Fanconi pathway and RECQ family genes. Notably, this study further reveals a large portion of still unexplained Li-Fraumeni(-like) cases, warranting comprehensive investigation of recently described candidate genes as well as noncoding regions of the TP53 gene in patients with Li-Fraumeni(-like) syndrome lacking TP53 variants in coding regions.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Mutação em Linhagem Germinativa/genética , Síndrome de Li-Fraumeni/genética , Adulto , Estudos de Coortes , Variações do Número de Cópias de DNA , Análise Mutacional de DNA/métodos , Feminino , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único , Proteína Supressora de Tumor p53/genética , Adulto Jovem
20.
Am J Med Genet A ; 176(6): 1449-1454, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29696793

RESUMO

KBG syndrome is a rare autosomal dominant disorder caused by constitutive haploinsufficiency of the ankyrin repeat domain-containing protein 11 (ANKRD11) being the result of either loss-of-function gene variants or 16q24.3 microdeletions. The syndrome is characterized by a variable clinical phenotype comprising a distinct facial gestalt and variable neurological involvement. ANKRD11 is frequently affected by loss of heterozygosity in cancer. It influences the ligand-dependent transcriptional activation of nuclear receptors and tumor suppressive function of tumor protein TP53. ANKRD11 thus serves as a candidate tumor suppressor gene and it has been speculated that its haploinsufficiency may lead to an increased cancer risk in KBG syndrome patients. While no systematic data are available, we report here on the second KBG syndrome patient who developed a malignancy. At 17 years of age, the patient was diagnosed with a left-sided paratesticular extrarenal malignant rhabdoid tumor. Genetic investigations identified a somatic truncating gene variant in SMARCB1, which was not present in the germline, and a constitutional de novo 16q24.3 microdeletion leading to a loss of the entire ANKRD11 locus. Thus, KBG syndrome was diagnosed, which was in line with the clinical phenotype of the patient. At present, no specific measures for cancer surveillance can be recommended for KBG syndrome patients. However, a systematic follow-up and inclusion of KBG syndrome patients in registries (e.g., those currently established for cancer prone syndromes) will provide empiric data to support or deny an increased cancer risk in KBG syndrome in the future.


Assuntos
Anormalidades Múltiplas/genética , Doenças do Desenvolvimento Ósseo/genética , Deleção Cromossômica , Cromossomos Humanos Par 16 , Deficiência Intelectual/genética , Tumor Rabdoide/genética , Neoplasias Testiculares/genética , Anormalidades Dentárias/genética , Anormalidades Múltiplas/etiologia , Adolescente , Doenças do Desenvolvimento Ósseo/etiologia , Facies , Feminino , Predisposição Genética para Doença , Humanos , Deficiência Intelectual/etiologia , Masculino , Linhagem , Proteínas Proto-Oncogênicas/genética , Tumor Rabdoide/tratamento farmacológico , Tumor Rabdoide/cirurgia , Neoplasias Testiculares/tratamento farmacológico , Neoplasias Testiculares/cirurgia , Anormalidades Dentárias/etiologia
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