Spectrum and Prevalence of Pathogenic Variants in Ovarian Cancer Susceptibility Genes in a Group of 333 Patients.

Constitutional loss-of-function pathogenic variants in the tumor suppressor genes BRCA1 and BRCA2 are widely associated with an elevated risk of ovarian cancer (OC). As only ~15% of OC individuals carry the BRCA1/2 pathogenic variants, the identification of other potential OC-susceptibility genes is of great clinical importance. Here, we established the prevalence and spectrum of the germline pathogenic variants in the BRCA1/2 and 23 other cancer-related genes in a large Polish population of 333 unselected OC cases. Approximately 21% of cases (71/333) carried the BRCA1/2 pathogenic or likely pathogenic variants, with c.5266dup (p.Gln1756Profs*74) and c.3700_3704del (p.Val1234Glnfs*8) being the most prevalent. Additionally, ~6% of women (20/333) were carriers of the pathogenic or likely pathogenic variants in other cancer-related genes, with NBN and CHEK2 reported as the most frequently mutated, accounting for 1.8% (6/333) and 1.2% (4/333) of cases, respectively. We also found ten pathogenic or likely pathogenic variants in other genes: 1/333 in APC, 1/333 in ATM, 2/333 in BLM, 1/333 in BRIP1, 1/333 in MRE11A, 2/333 in PALB2, 1/333 in RAD50, and 1/333 in RAD51C, accounting for 50% of all detected variants in moderate- and low-penetrant genes. Our findings confirmed the presence of the additional OC-associated genes in the Polish population that may improve the personalized risk assessment of these individuals.

Cancer predisposing BARD1 mutations affect exon skipping and are associated with overexpression of specific BARD1 isoforms.

BARD1 is the main binding partner of BRCA1 and is required for its stability and tumor-suppressor functions. In breast cancer and other epithelial cell carcinomas, alternatively spliced isoforms of BARD1 are highly upregulated and correlated with poor outcome. Recent data indicate that germline mutations of BARD1 may predispose to breast and/or ovarian cancer. To evaluate the role of BARD1 germline mutations in predisposition to ovarian cancer we scanned a cohort of 255 patients for the presence of previously reported mutations located in exons 5, 8 and 10 using high-resolution melting analysis. Within this group we identified single-patients carrying mutation in exon 8 (c.1690C>T, p.Gln564Ter), two different variants in exon 10 (c.1972C>T, p.Arg658Tyr; c.1977A>G, p.=) and a carrier of novel missense mutation located in exon 5 (c.1361C>T, p.Pro454Leu). Three out of four identified mutations alter exonic splicing enhancing motives and result in expression of incorrect splicing skipping of exons 5, 8, and 2-9, respectively. Our data indicate that BARD1 variants may predispose to ovarian cancer in limited number of patients although based on actual data it is difficult to estimate its actual penetrance.

Analysis of large mutations in BARD1 in patients with breast and/or ovarian cancer: the Polish population as an example.

Only approximately 50% of all familial breast cancers can be explained by known genetic factors, including mutations in BRCA1 and BRCA2. One of the most extensively studied candidates for breast and/or ovarian cancer susceptibility is BARD1. Although it was suggested that large mutations may contribute substantially to the deleterious variants of BARD1, no systematic study of the large mutations in BARD1 has been performed. To further elucidate the role of large mutations in BARD1, we designed a multiplex ligation-dependent probe amplification (MLPA) assay and performed an analysis of 504 women with a familial breast and/or ovarian cancer and 313 patients with ovarian cancer. The investigation did not reveal any large mutations in the BARD1 gene. Although the analysis was not focused on identification of small mutations, we detected seven deleterious or potentially deleterious point mutations, which contribute substantially to the total number of BARD1 mutations detected so far. In conclusion, although we cannot exclude the presence of large mutations in BARD1, our study indicates that such mutations do not contribute substantially to the risk of breast and/or ovarian cancer. However, it has to be noted that our results may be specific to the Polish population.

Mutational analysis of BRCA1/2 in a group of 134 consecutive ovarian cancer patients. Novel and recurrent BRCA1/2 alterations detected by next generation sequencing.

The importance of proper mutational analysis of BRCA1/2 in individuals at risk for hereditary breast and ovarian cancer syndrome is widely accepted. Standard genetic screening includes targeted analysis of recurrent, population-specific mutations. The purpose of the study was to establish the frequency of germline BRCA1/2 mutations in a group of 134 unrelated patients with primary ovarian cancer. Next generation sequencing analysis revealed a presence of 20 (14.9%) mutations, where 65% (n = 13) were recurrent BRCA1 alterations included in the standard diagnostic panel in northern Poland. However, the remaining seven BRCA1/2 mutations (35%) would be missed by the standard approach and were detected in unique patients. A substantial proportion (n = 5/12; 41%) of mutation-positive individuals with complete family history reported no incidence of breast or ovarian cancer in their relatives. This observation, together with the raising perspectives for personalized therapy targeting BRCA1/2 signaling pathways indicates the necessity of comprehensive genetic screening in all ovarian cancer patients. However, due to the limited sensitivity of the standard genetic screening presented in this study (65%) an application of next generation sequencing in molecular diagnostics of BRCA1/2 genes should be considered.

Are bilateral breast cancers different from breast cancers coexisting with ovarian cancer? An immunohistochemical analysis aimed at intrinsic tumor phenotype.

RATIONALE: Bilateral breast cancers (BBC) and breast cancers coexisting with ovarian cancer (BOCS) are associated with genetic predisposition more frequently than sporadic cases. We compared the phenotypes of these tumors to better understand their pathomechanisms and aid the guiding of their clinical management. MATERIALS AND METHODS: Tumor morphology and expression of ER, PgR, HER2, Ki67, CK5/6, E-cadherin, vimentin and EGFR were assessed in a tissue microarray containing cores from 174 BBC, 23 BOCS and 2 BBC + BOCS. RESULTS: BOCS tumors were characterized by higher incidence of EGFR expression, HER2 negativity and lower incidence of intraductal component. HER2-positive phenotypes were marginally more frequent in the BBC group and triple negative tumors - in BOCS. CONCLUSION: Breast cancers from BOCS patients are characterized by more aggressive phenotype, most probably related to their more frequent association with BRCA1 mutation.

Limited significance of family history for presence of BRCA1 gene mutation in Polish breast and ovarian cancer cases.

It is estimated that about 5-10% of ovarian and 2-5% of all breast cancer patients are carriers of a germline BRCA1 or BRCA2 gene mutation. Most families with detected BRCA1 or BRCA2 gene mutation are qualified for molecular testing on the basis of family history of breast or ovarian cancers. The purpose of our study was to establish the frequency of positive family history of cancer in a series of Polish consecutive breast and ovarian cancer patients in two groups, with and without the BRCA1 gene mutations. We analysed the prevalence of four of the most common BRCA1 mutations: 5382insC (c.5266dupC), 300T>G (p.181T>G), 185delAG (c.68_69delAG) and 3819del5 (c.3700_3704del5). The patient group consisted of 1,845 consecutive female breast and 363 ovarian cancer cases. 19 out of 37 (51%) of BRCA1-positive ovarian cancer patients and 21 out of 55 (39%) BRCA1-positive breast cancer had negative family history of breast and/or ovarian cancer among first- and second-degree relatives. In ovarian cancer patients, negative family history was more frequent in those with 300T>G BRCA1 gene mutation than in 5382insC carriers. This finding indicates the necessity of searching for 300T>G mutation in families with a single diagnosis of ovarian cancer in family. The high frequency of mutations detected in breast cancer patients lacking obvious family history shows that breast cancer patients should be qualified for genetic testing on the basis of wide clinical and pathological criteria.

Cancer predisposing BARD1 mutations in breast-ovarian cancer families.

The breast cancer susceptibility gene BARD1 (BRCA1-associated RING domain protein, MIM# 601593) acts with BRCA1 in DNA double-strand break (DSB) repair and also in apoptosis initiation. We screened 109 BRCA1/2 negative high-risk breast and/or ovarian cancer patients from North-Eastern Poland for BARD1 germline mutations using a combination of denaturing high-performance liquid chromatography and direct sequencing. We identified 16 different BARD1 sequence variants, five of which are novel. Three of them were suspected to be pathogenic, including a protein truncating nonsense mutation (c.1690C>T, p.Gln564X), a splice mutation (c.1315-2A>G) resulting in exon 5 skipping, and a silent change (c.1977A>G) which alters several exonic splicing enhancer motifs in exon 10 and results in a transcript lacking exons 2-9. Our findings suggest that BARD1 mutations may be regarded as cancer risk alleles and warrant further investigation to determine their actual contribution to non-BRCA1/2 breast and ovarian cancer families.

Prevalence of the most frequent BRCA1 mutations in Polish population.

The purpose of our study was to establish the frequency and distribution of the four most common BRCA1 mutations in Polish general population and in a series of breast cancer patients. Analysis of the population frequency of 5382insC (c.5266dupC), 300T >G (p.181T >G), 185delAG (c.68_69delAG) and 3819del5 (c.3700_3704del5) mutations of the BRCA1 gene were performed on a group of respectively 16,849, 13,462, 12,485 and 3923 anonymous samples collected at birth in seven Polish provinces. The patient group consisted of 1845 consecutive female breast cancer cases. The most frequent BRCA1 mutation in the general population was 5382insC found in 29 out of 16,849 samples (0.17%). 300T >G and 3819del5 mutations were found in respectively 11 of 13,462 (0.08%) and four of 3923 (0.1%) samples. The population prevalence for combined Polish founder 5382insC and 300T >G mutations was 0.25% (1/400). The frequencies of 5382insC and 300T >G carriers among consecutive breast cancer cases were, respectively, 1.9% (35/1845) and 1.2% (18/1486). Comparing these data with the population frequency, we calculated the relative risk of breast cancer for 5382insC mutation at OR = 17 and for 300T >G mutation at OR = 26. Our results, based on large population studies, show high frequencies of founder 5382insC and 300T >G BRCA1 mutations in Polish general population. Carriage of one of these mutations is connected with a very high relative risk of breast cancer.

BRCA1 and BRCA2 point mutations and large rearrangements in breast and ovarian cancer families in Northern Poland.

Sixty-four Polish families with a history of breast and/or ovarian cancer were screened for mutations in the BRCA1/2 genes using a combination of denaturing high performance liquid chromatography (DHPLC) and sequencing. Two thirds (43/64; 67%) of the families were found to carry deleterious mutations, of which the most frequent were BRCA1 5382insC (n=22/43; 51%) and Cys61Gly (n=9/43; 20%). Two other recurrent mutations were BRCA1 185delAG (n=3) and 3819del5 (n=4), together accounting for 16% of the 43 mutation-positive cases. We also found three novel mutations (BRCA1 2991del5, BRCA2 6238ins2del21 and 8876delC) which combined with findings from our earlier study of 60 Northern Polish families. Moreover, screening of 43 BRCA1/2 negative families for the presence of large rearrangements by multiplex ligation-dependent probe amplification (MLPA) resulted in the finding of two additional BRCA1 mutations: a deletion of exons 1A, 1B and 2, and a deletion of exons 17-19, both present in single families. We conclude that the Polish population has a diverse mutation spectrum influenced by strong founder effects. However, families with strong breast/ovarian cancer history who are negative for these common mutations should be offered a complete BRCA gene screening, including MLPA analysis.

High frequency of BRCA1/2 germline mutations in consecutive ovarian cancer patients in Poland.

BACKGROUND: We estimated the prevalence of BRCA1/2 germline mutations in consecutive ovarian cancers and correlated the mutation status with clinicopathological features. METHODS: 151 consecutive primary ovarian cancer patients were screened for BRCA1/2 germline mutations. RESULTS: We identified BRCA1/2 germline mutations in 21 (13.9%) patients. Seventeen (81%) of carriers have BRCA1 and four (19%) have BRCA2 mutation. BRCA1/2 carriers have a distinctly longer overall survival than sporadic cases (log-rank, p=0.014). CONCLUSIONS: The relatively high proportion of BRCA1/2 carriers among unselected ovarian cancer patients indicates the necessity of searching for recurrent BRCA mutations in each case of ovarian carcinoma. This routine screen should be widened to include denaturing high performance liquid chromatography (DHPLC) analysis of both exons 11 of BRCA1 and BRCA2 genes in women with positive family history.

Germline NBS1 mutations in families with aggregation of Breast and/or ovarian cancer from north-east Poland.

BACKGROUND: NBS1 gene, which product participates in DNA repair, has been postulated to be a susceptibility factor for a number of types of cancer, including breast cancer. The carrier frequency of the 657del5 and I171V NBS1 gene mutations among Polish patients with familial breast and/or ovarian cancer was compared with that of randomly selected newborns. PATIENTS AND METHODS: Using allele-specific amplification-polymerase chain reaction (ASAPCR) and restriction fragment length polymorphismpolymerase chain reaction (RFLP-PCR) techniques, blood samples were analysed from 250 patients with breast or/and ovarian cancer and a total number of 4,000 for 657del5 mutation and 1,300 for I1171V mutation controls. RESULTS: Although an increased frequency of both mutations in cancer cases - 0.8% of 657del5 and 2.4% of I171V, compared to controls - 0.52% and 1.38%, respectively, was found, the differences were not statistically significant. CONCLUSION: Our results indicate that NBS1 mutations do not contribute significantly to breast or ovarian cancer development.

Frontometaphyseal dysplasia: mutations in FLNA and phenotypic diversity.

Frontometaphyseal dysplasia is an X-linked trait primarily characterized by a skeletal dysplasia comprising hyperostosis of the skull and modeling anomalies of the tubular bones. Extraskeletal features include tracheobronchial, cardiac, and urological malformations. A proportion of individuals have missense mutations or small deletions in the X-linked gene, FLNA. We report here our experience with comprehensive screening of the FLNA gene in a group of 23 unrelated probands (11 familial instances, 12 simplex cases; total affected individuals 32) with FMD. We found missense mutations leading to substitutions in the actin-binding domain and within filamin repeats 9, 10, 14, 16, 22, and 23 of filamin A in 13/23 (57%) of individuals in this cohort. Some mutations present with a male phenotype that is characterized by a severe skeletal dysplasia, cardiac, and genitourinary malformations that leads to perinatal death. Although no phenotypic feature consistently discriminates between females with FMD who are heterozygous for FLNA mutations and those in whom no FLNA mutation can be identified, there is a difference in the degree of skewing of X-inactivation between these two groups. This observation suggests that locus heterogeneity may exist for this disorder.

HER2 Amplification Has no Prognostic Value in Sporadic and Hereditary Ovarian Tumours.

Whereas HER2 amplification is a well-known phenomenon in breast tumours, its frequency and clinical importance in ovarian cancer have not been established. The aim of the study was to compare the frequency of HER2 amplification in hereditary (BRCA-positive) and sporadic (BRCA-negative) ovarian tumours and to estimate the association of this gene alteration on clinical outcome in ovarian cancer patients. We analysed HER2 amplification in 53 ovarian tumours: 20 from mutation carriers (18 in BRCA1 and 2 in BRCA2 gene) and 33 from non-carriers. Fluorescence in situ hybridization for HER2 was performed on 'touch' slides from frozen tumour samples or formalin-fixed, paraffin-embedded tissue. Our results indicate that high amplification (HER2: centromere ratio>5) is an infrequent phenomenon in ovarian tumours (6/53 cases). It occurs in both hereditary (4/20) and sporadic (2/33) tumours and no difference in the frequency of HER2 amplification exists between these groups. There is no significant difference in the clinical outcome of patients with HER2 amplified and non-amplified tumours (p = 0.3). Our results suggest a different biological role of HER2 amplification in ovarian and breast cancer.

Microdeletion of target sites for insulator protein CTCF in a chromosome 11p15 imprinting center in Beckwith-Wiedemann syndrome and Wilms' tumor.

We have analyzed several cases of Beckwith-Wiedemann syndrome (BWS) with Wilms' tumor in a familial setting, which give insight into the complex controls of imprinting and gene expression in the chromosome 11p15 region. We describe a 2.2-kbp microdeletion in the H19/insulin-like growth factor 2 (IGF2)-imprinting center eliminating three target sites of the chromatin insulator protein CTCF that we believe here is necessary, but not sufficient, to cause BWS and Wilms' tumor. Maternal inheritance of the deletion is associated with IGF2 loss of imprinting and up-regulation of IGF2 mRNA. However, in at least one affected family member a second genetic lesion (a duplication of maternal 11p15) was identified and accompanied by a further increase in IGF2 mRNA levels 35-fold higher than control values. Our results suggest that the combined effects of the H19/IGF2-imprinting center microdeletion and 11p15 chromosome duplication were necessary for manifestation of BWS.

Prevalence and clinical correlations of BRCA1/BRCA2 unclassified variant carriers among unselected primary ovarian cancer cases - preliminary report.

The objective of this study was to determine the prevalence of BRCA1 and BRCA2 gene mutations in unselected ovarian cancer patients, and to analyse clinical and pathological features of ovarian cancer unclassified variant mutation carriers in comparison with BRCA1 pathogenic mutation carriers and sporadic cases. A consecutive sample of 205 women with primary ovarian cancer was screened for mutations in the BRCA1 and BRCA2 genes using a direct test for small deletions and insertions, conformational sensitive gel electrophoresis and direct sequencing. Data regarding medical and familial history were collected using questionnaires. Clinical and pathological data were extracted from medical records. Unclassified variants and polymorphic mutations accounted for 8% (n = 16) and 6% (n = 13) of all cases, respectively. BRCA1 pathogenic mutations were found in 18 (9%) patients. None were found in BRCA2. The mean age of onset for BRCA1-associated tumours was 43.1 years (standard deviation (SD: 7.3) whereas in the patients with an unclassified variant, polymorphism, or no detectable gene changes, the mean age of onset ranged from 49.5-56.4 years. The most significant predictors for pathogenic or unclassified variant changes in BRCA1 in ovarian cancer patients were a younger age of onset and a history of hyperthyroidism and infertility. Except for infertility and hyperthyroidism, unclassified variant-linked ovarian tumours share features with sporadic tumours rather than with BRCA1 pathogenic mutations.

Cytogenetic analysis and clinical significance of chromosome 7 aberrations in acute leukaemia.

The analysis was performed on bone marrow cells derived from 96 patients with acute leukaemia (AL): 76 with acute myelogenous leukaemia (AML) and 20 with acute lymphoblastic leukaemia (ALL). Aberrations of chromosome 7 were revealed in 20 (21%) of 96 analysed cases: in 14 (18%) with AML and in six (30%) with ALL. Structural aberrations, present in 13 patients (eight with AML and five with ALL), were unbalanced and led to partial monosomy (12 cases) or trisomy (four cases) of chromosome 7. Twelve (86%) out of 14 AML and all the ALL patients with chromosome 7 aberrations had complex karyotypes in their bone marrow cells. Monosomy 7 and 7q losses were frequently observed in the AML group, whereas, in the ALL group, gains in 7q and losses in the short arms constituted most chromosome 7 aberrations. The occurrence of monosomy, or of losses in 7q, results in a worse response to induction therapy in AML patients. The complete remission (CR) rate was significantly lower in this group in comparison to the group of AML patients with a normal karyotype (p = 0.01) in bone marrow cells.

Hereditary ovarian cancer in Poland.

There is increasing evidence that hereditary factors play a greater role in ovarian cancer than in any of the other common cancers of adulthood. This is attributable, to a large extent, to a high frequency of mutations in the BRCA1 or BRCA2 genes. In Poland, 3 common founder mutations in BRCA1 account for the majority of families with identified BRCA mutations. Our study was conducted in order to estimate the prevalence of any of 3 founder BRCA1 mutations (5382insC, C61G and 4153delA) in 364 unselected women with ovarian cancer, and among 177 women with ovarian cancer and a family history of breast or ovarian cancer. A mutation was identified in 49 out of 364 unselected women with ovarian cancer (13.5%) and in 58 of 177 women with familial ovarian cancer (32.8%). The majority of women with ovarian cancer and a BRCA1 mutation have no family history of breast or ovarian cancer. The high frequency of BRCA1 mutations in Polish women with ovarian cancer supports the recommendation that all Polish women with ovarian cancer should be offered testing for genetic susceptibility, and that counseling services be made available to them and to their relatives. It is important that mutation surveys be conducted in other countries prior to the introduction of national genetic screening programs.

BRCA1 and BRCA2 mutation analysis in breast-ovarian cancer families from northeastern Poland.

Sixty high-risk breast and/or ovarian cancer families from North-Eastern Poland were screened for germline mutations in BRCA1 (MIM# 113705) and BRCA2 (MIM# 600185), using a combination of protein truncation test, denaturing high-performance liquid chromatography and direct sequencing. Sixteen (27%) of the families were found to carry nine different BRCA mutations, including 14 families with BRCA1 mutation and two families with BRCA2 mutation. The results suggest the presence of two strong BRCA1 founder mutations in the Polish population - 5382insC (6 families) and 300T>G (Cys61Gly; 3 families). The remaining seven mutations were found in single families and included three previously reported BRCA1 mutations (185delAG, 2682C>T [Gln855Ter] and 3819del5), a novel BRCA1 mutation (IVS14+1G>A), as well as two BRCA2 mutations (4088delA and 7985G>A [Trp2586Ter]) not previously observed in Polish families. We confirm the strong influence of two Central-Eastern European BRCA1 founder mutations in familial breast and/or ovarian cancer in Poland. We also conclude that the Polish population has a more dispersed BRCA mutation spectrum than had been earlier thought. This warrants further careful BRCA mutation screening in order to optimise genetic counselling and disease prevention in affected families.

Partial trisomy of distal 5q and partial monosomy of Xp as a result of mating between two translocation carriers: a female with a balanced translocation t(X;5)(p11;q31) and a male with a der(13;14)(q10;q10)--a case report and a family study.

This paper presents the family of a dysmorphic child with the phenotypic features of Turner's syndrome and 5q trisomy, whose parents are both carriers of a balanced translocation. The parents' karyotypes are 46,X,t(X;5)(p11.1;q31) and 45,XY,der(13;14)(q10;q10), respectively.