The 185delAG BRCA1 mutation originated before the dispersion of Jews in the diaspora and is not limited to Ashkenazim

BRCA awareness and testing experience in the UK Jewish population: a qualitative study

BACKGROUND

1 in 40 UK Jewish individuals carry a pathogenic variant in BRCA1/BRCA2. Traditional testing criteria miss half of carriers, and so population genetic testing is being piloted for Jewish people in England. There has been no qualitative research into the factors influencing BRCA awareness and testing experience in this group. This study aimed to explore these and inform improvements for the implementation of population genetic testing.

METHODS

Qualitative study of UK Jewish adults who have undergone BRCA testing. We conducted one-to-one semistructured interviews via telephone or video call using a predefined topic guide, until sufficient information power was reached. Interviews were audio-recorded, transcribed verbatim and interpreted using applied thematic analysis.

RESULTS

32 individuals were interviewed (28 carriers, 4 non-carriers). We interpreted five themes intersecting across six time points of the testing pathway: (1) individual differences regarding personal/family history of cancer, demographics and personal attitudes/approach; (2) healthcare professionals' support; (3) pathway access and integration; (4) nature of family/partner relationships; and (5) Jewish community factors. Testing was largely triggered by connecting information to a personal/family history of cancer. No participants reported decision regret, although there was huge variation in satisfaction. Suggestions were given around increasing UK Jewish community awareness, making information and support services personally relevant and proactive case management of carriers.

CONCLUSIONS

There is a need to improve UK Jewish community BRCA awareness and to highlight personal relevance of testing for individuals without a personal/family history of cancer. Traditional testing criteria caused multiple issues regarding test access and experience. Carriers want information and support services tailored to their individual circumstances.

Germline mutational variants of Turkish ovarian cancer patients suspected of Hereditary Breast and Ovarian Cancer (HBOC) by next-generation sequencing

Hereditary Breast and Ovarian Cancer (HBOC) syndrome is characterized by an increased risk of developing breast cancer (BC) and ovarian cancer (OC) due to inherited genetic mutations. Understanding the genetic variants associated with HBOC is crucial for identifying individuals at high risk and implementing appropriate preventive measures. The study included 630 Turkish OC patients with confirmed diagnostic criteria of The National Comprehensive Cancer Network (NCCN) concerning HBOC. Genomic DNA was extracted from peripheral blood samples, and targeted Next-generation sequencing (NGS) was performed. Bioinformatics analysis and variant interpretation were conducted to identify pathogenic variants (PVs). Our analysis revealed a spectrum of germline pathogenic variants associated with HBOC in Turkish OC patients. Notably, several pathogenic variants in BRCA1, BRCA2, and other DNA repair genes were identified. Specifically, we observed germline PVs in 130 individuals, accounting for 20.63% of the total cohort. 76 distinct PVs in genes, BRCA1 (40 PVs), BRCA2 (29 PVs), ATM (1 PV), CHEK2 (2 PVs), ERCC2 (1 PV), MUTYH (1 PV), RAD51C (1 PV), and TP53 (1PV) and also, two different PVs (i.e., c.135-2 A>G p.? in BRCA1 and c.6466_6469delTCTC in BRCA2) were detected in a 34-year-old OC patient. In conclusion, our study contributes to a better understanding of the genetic variants underlying HBOC in Turkish OC patients. These findings provide valuable insights into the genetic architecture of HBOC in the Turkish population and shed light on the potential contribution of specific germline PVs to the increased risk of OC.

TP53 germline pathogenic variants in modern humans were likely originated during recent human history

TP53 is crucial for maintaining genome stability and preventing oncogenesis. Germline pathogenic variation in TP53 damages its function, causing genome instability and increased cancer risk. Despite extensive study in TP53, the evolutionary origin of the human TP53 germline pathogenic variants remains largely unclear. In this study, we applied phylogenetic and archaeological approaches to identify the evolutionary origin of TP53 germline pathogenic variants in modern humans. In the phylogenic analysis, we searched 406 human TP53 germline pathogenic variants in 99 vertebrates distributed in eight clades of Primate, Euarchontoglires, Laurasiatheria, Afrotheria, Mammal, Aves, Sarcopterygii and Fish, but we observed no direct evidence for the cross-species conservation as the origin; in the archaeological analysis, we searched the variants in 5031 ancient human genomes dated between 45045 and 100 years before present, and identified 45 pathogenic variants in 62 ancient humans dated mostly within the last 8000 years; we also identified 6 pathogenic variants in 3 Neanderthals dated 44000 to 38515 years before present and 1 Denisovan dated 158 550 years before present. Our study reveals that TP53 germline pathogenic variants in modern humans were likely originated in recent human history and partially inherited from the extinct Neanderthals and Denisovans.

Ethnic-specificity, evolution origin and deleteriousness of Asian BRCA variation revealed by over 7500 BRCA variants derived from Asian population

Pathogenic variation in BRCA1 and BRCA2 (BRCA) causes high risk of breast and ovarian cancer, and BRCA variation data are important markers for BRCA-related clinical cancer applications. However, comprehensive BRCA variation data are lacking from the Asian population despite its large population size, heterogenous genetic background and diversified living environment across the Asia continent. We performed a systematic study on BRCA variation in Asian population including extensive data mining, standardization, annotation and characterization. We identified 7587 BRCA variants from 685 592 Asian individuals in 40 Asia countries and regions, including 1762 clinically actionable pathogenic variants and 4915 functionally unknown variants (https://genemutation.fhs.um.edu.mo/Asian-BRCA/). We observed the highly ethnic-specific nature of Asian BRCA variants between Asian and non-Asian populations and within Asian populations, highlighting that the current European descendant population-based BRCA data is inadequate to reflect BRCA variation in the Asian population. We also provided archeological evidence for the evolutionary origin and arising time of Asian BRCA variation. We further provided structural-based evidence for the deleterious variants enriched within the functionally unknown Asian BRCA variants. The data from our study provide a current view of BRCA variation in the Asian population and a rich resource to guide clinical applications of BRCA-related cancer for the Asian population.

Population-based screening of Uruguayan Ashkenazi Jews for recurrent BRCA1 and BRCA2 pathogenic sequence variants

In Ashkenazi Jews (AJ) three recurring pathogenic sequence variants (PSVs) are detected in ~2.5% of the general population in the BRCA1 (c.68_69del = 185delAG, c.5266dup = 5382insC), and BRCA2 (c.5946del = 6174delT). Population‐based screening for these PSVs in AJ women is part of the health basket in Israel. To assess the feasibility and outcome of BRCA genotyping in the Jewish population of Uruguay, AJ in the greater Montevideo area were recruited using ethically approved protocol and without pretest counseling were genotyped for the three predominant AJ PSVs in the BRCA genes. Independently confirmed PSV carriers were counseled, and genetic testing was offered to additional family members. Overall, 327 participants were enrolled: 312 (95%) female, 261 (80%) had all four grandparents AJ, and 14 (4%) women were breast cancer survivors with a mean age ± standard deviation (SD) 50 ± 11.5 years. The BRCA1 c.68_69del PSV was detected in three cancer free participants (0.92%, CI 95% 0.31–2.6), all with a suggestive family history. No carriers of the other two recurrent PSVs were detected. Online oncogenetic counseling was provided for all carriers. In conclusion, the rate of the BRCA1 c.68_69del PSV was similar with the rate in other AJ communities. AJ population BRCA genotyping screens in Uruguay seem feasible and should be promoted.

Prevalence of specific and recurrent/founder pathogenic variants in BRCA genes in breast and ovarian cancer in North Africa

Background

Elucidation of specific and recurrent/founder pathogenic variants (PVs) in BRCA (BRCA1 and BRCA2) genes can make the genetic testing, for breast cancer (BC) and/or ovarian cancer (OC), affordable for developing nations.

Methods

To establish the knowledge about BRCA PVs and to determine the prevalence of the specific and recurrent/founder variants in BRCA genes in BC and/or OC women in North Africa, a systematic review was conducted in Morocco, Algeria, and Tunisia.

Results

Search of the databases yielded 25 relevant references, including eleven studies in Morocco, five in Algeria, and nine in Tunisia. Overall, 15 studies investigated both BRCA1 and BRCA2 genes, four studies examined the entire coding region of the BRCA1 gene, and six studies in which the analysis was limited to a few BRCA1 and/or BRCA2 exons. Overall, 76 PVs (44 in BRCA1 and32 in BRCA2) were identified in 196 BC and/or OC patients (129 BRCA1 and 67 BRCA2 carriers). Eighteen of the 76 (23.7%) PVs [10/44 (22.7%) in BRCA1 and 8/32 (25%) in BRCA2] were reported for the first time and considered to be novel PVs. Among those identified as unlikely to be of North African origin, the BRCA1 c.68_69del and BRCA1 c.5266dupC Jewish founder alleles and PVs that have been reported as recurrent/founder variants in European populations (ex: BRCA1 c.181T>G, BRCA1 c1016dupA). The most well characterized PVs are four in BRCA1 gene [c.211dupA (14.7%), c.798_799detTT (14%), c.5266dup (8.5%), c.5309G>T (7.8%), c.3279delC (4.7%)] and one in BRCA2 [c.1310_1313detAAGA (38.9%)]. The c.211dupA and c.5309G>T PVs were identified as specific founder variants in Tunisia and Morocco, accounting for 35.2% (19/54) and 20.4% (10/49) of total established BRCA1 PVs, respectively. c.798_799delTT variant was identified in 14% (18/129) of all BRCA1 North African carriers, suggesting a founder allele. A broad spectrum of recurrent variants including BRCA1 3279delC, BRCA1 c.5266dup and BRCA2 c.1310_1313detAAGA was detected in 42 patients. BRCA1 founder variants explain around 36.4% (47/129) of BC and outnumber BRCA2 founder variants by a ratio of ≈3:1.

Conclusions

Testing BC and/or OC patients for the panel of specific and recurrent/founder PVs might be the most cost-effective molecular diagnosis strategy.

A case–control study of BRCA1 founder mutations 185delAG and 5382insC in a cohort of Egyptian ovarian cancer patients using pyrosequencing technique

Background

Ovarian cancer (OC) is considered a leading cause of death among women with gynecological malignancies. OC, like breast cancer, shows a familial predisposition to germline mutations in genes BRCA1 or BRCA2, which have proved to play important roles in the incidence and progression of cancers. In Arab countries there are limited data concerning BRCA1 or BRCA2 founder mutations associated with familial ovarian cancer (FOC). Therefore, the aim of this pilot study was to assess two common founder mutations of BRCA1 (185delAG and 5382insC) in a cohort of Egyptian patients with FOC. The study included fifty female patients with FOC and twenty healthy controls. Clinical, laboratory, and pathological findings were assessed as well as response to therapy. Genetic testing for BRCA1 (185delAG and 5382insC) mutations was performed on peripheral blood samples using a short-fragment sequencer (pyrosequencer).

Results

The BRCA1 185delAG mutation was not observed in either the FOC patients or the controls. However, the carrier frequency of heterozygous BRCA1 5382insC mutation was 8%. All the FOC patients with a BRCA1 5382insC mutation had a positive family history of cancer (p = 0.009). All carriers of the BRCA1 5382insC mutation showed a preliminary good response to chemotherapy. The majority of carrier patients were diagnosed at an advanced stage of the disease with high-grade tumors and distant metastasis (75% of cases).

Conclusion

The frequency of the BRCA1 5382insC mutation in FOC patients was 8%. The strong association between the mutation and the positive family history suggests that a wider screening for BRCA1 founder mutations would be valuable in predicting high-risk individuals.

Mapping the Diverse Genetic Disorders and Rare Diseases Among the Syrian Population: Implications on Refugee Health and Health Services in Host Countries

The aim of this systematic review is to provide physicians and researchers with a comprehensive list of reported genetic disorders in patients of Syrian origin-those who have become part of the largest displaced population globally-and to highlight the need to consider migrant population-based risk for the development of genetic disease control and prevention programs. This review was performed based on the 2015 PRISMA and the international prospective register of systematic reviews. The present review reports on a total of 166 genetic disorders (only 128 reported on OMIM) identified in the Syrian population. Of these disorders, 27% are endocrine-, nutritional- and metabolic-related diseases. Second to metabolic disorders are congenital malformations, deformations and chromosomal abnormalities. Diseases of the blood and the blood-forming organs accounted for 13% of the total genetic disorders. The majority of the genetic disorders reported in Syrian patients followed an autosomal recessive mode of inheritance. These findings are a reflection of the high rates of consanguineous marriages that favor the increase in incidence of these diseases. From the diseases that followed an autosomal recessive mode of inheritance, 22% are reported to be only present in Syria and other regional countries. Twelve of these genetic diseases were identified to be strictly diagnosed in individuals of Syrian origin. The present systematic review highlights the need to develop programs that target genetic disorders affecting Syrian migrants in host countries. These programs would have potential financial and economic benefits, as well as a positive impact on the physical and mental health of members of the Syrian refugee community and those of their host societies. In turn, this would decrease the burden on the health systems in host countries.

A systematic review of the prevalence of germline pathogenic variants in patients with pancreatic cancer

The genetics of pancreatic ductal adenocarcinoma (PDAC) is complex with patients reported to harbor germline pathogenic variants (PVs) in many different genes. PDAC patients with familial pancreatic cancer (FPC) are more likely to carry germline PVs but there is no consensus main gene involved in FPC. We performed a systematic review of publications from PubMed and Scopus reporting PVs in patients with FPC, sporadic pancreatic cancer (SPC) and unselected cohorts of PDAC patients undergoing genetic testing and calculated a cumulative prevalence of PVs for each gene evaluated across these three groups of patients. When available, variants in the selected publications were reclassified according to the American College of Medical Genetics and Genomics classification system and used for prevalence calculations if classified as pathogenic or likely pathogenic. We observed an increased prevalence of PVs in FPC compared to SPC or unselected PDAC patients for most of the 41 genes reported. The genes with the highest prevalence of carriers of PVs in FPC were ATM, BRCA2, and CDKN2A. BRCA2 and ATM showed the highest prevalence of PVs in both SPC and unselected PDAC cohorts. Several genes with the highest prevalence of PVs are involved in breast and ovarian cancer suggesting strong overlap with underlying genetics in these disorders but no single gene was predominant. More research is needed to further understand the risk of PDAC associated with these many diverse genes.

The role of pathologists in recognition of morphologic and biologic features of genetically mutated breast cancer

The recent introduction of genomic medicine and emphasis on optimizing breast cancer risk reduction mortalities has provided opportunities for pathologists to partner with clinicians in advancing the diagnosis and management of breast cancer patients. The discovery of breast cancer genes BRCA1, BRCA2, and other breast cancer genes is considered a major breakthrough in the understanding of hereditary breast cancer. These discoveries have contributed to investigate the nature of tumorigenesis and the genetic and molecular pathology in multistep tumor development, as well as their relationship to endocrine and environmental factors. The recognition of unique morphologic and biological features associated with genetically mutated breast cancer by pathologists may have an impact on appropriate follow-up management of breast cancer patients.

Mutations in BRCA-related breast and ovarian cancer in the South African Indian population: A descriptive study

Knowledge of the genetic landscape of a specific population group is vital for population-specific diagnosis and treatment of familial breast cancer. Although BRCA-related diagnostic testing has long been implemented in South Africa, the genotyping approach previously failed for the SA Indian population as it was based on other SA population groups. Because this population is uniquely admixed, the lack of population-specific data resulted in the implementation of comprehensive mutation screens for BRCA1/2. A total of 223 female patients were screened for clinically actionable variants. High-resolution melting analysis (HRMA) was used to screen 88 patients for DNA alterations in the coding and splice site boundaries of BRCA1 exons 2-9, BRCA1 exons 11-23, BRCA2 exons 2-9 and BRCA2 exons 12-27. The protein truncation test (PTT) was used to screen the three larger exons (BRCA1 exon 10 and BRCA2 exons 10 and 11) for protein termination changes. Multiplex ligation-dependent probe amplification (MLPA) was used to determine the presence of larger indels and possible copy number differences. Next Generation Sequencing (NGS) was performed on the remaining 135 samples. All potential variants were confirmed by performing Sanger DNA sequencing. The search revealed 28 different pathogenic heterozygotic variants, together with nine variants of unknown significance (VUS). The results suggested that the SA Indian population represents a different genetic admixture compared to that of mainland India, as only five pathogenic variants corresponded to those reported for mainland India. Familial breast cancer testing for SA Indian patients should therefore be performed as comprehensively as possible as the pathogenic variants seem to be family- rather than population-specific. Furthermore, predictive testing of family members will contribute to relieve the financial burden on the country's healthcare system, as increased surveillance and appropriate management could prevent disease.

A comprehensive reference for BRCA1/2 genes pathogenic variants in Iran: published, unpublished and novel

BRCA1 and BRCA2 are two prominent genes that account for about 20-40% of inherited breast cancer. Mutations in these genes are often associated with clustering of especially early-onset cancers in the family. The spectrum of BRCA variants showed a significant difference between geographic regions and ethnicities. The frequency and spectrum of BRCA mutations in Iran, a country in southwest Asia, have not yet been thoroughly studied. Here, for the first time, all published and not published BRCA pathogenic variants are presented. Among 1040 high risk families (1258 cases) which were detected, 116 families were found to carry pathogenic variants in either BRCA1 or BRCA2. Altogether 89 distinct types of pathogenic variants have been detected in Iran, including 41 in BRCA1 and 48 in BRCA2. 16 out of 89 mutations had not been previously reported in Iran and are presented for the first time in this article, among which 4 mutations are novel worldwide. 20% of families had one of the seven most commonly observed mutations, including c.81-1G > C, c.66_67delAG, c.4609C>T, c.1568delT, c.1961delA, in BRCA1 and: c.3751_3752insA, c.8585dupT in BRCA2. Combining the data from published articles and our study which has not been published before, a comprehensive table is created as a reference for entire BRCA pathogenic variants and their frequencies in Iran.

Mutational Landscape for Indian Hereditary Breast and Ovarian Cancer Cohort Suggests Need for Identifying Population Specific Genes and Biomarkers for Screening

BACKGROUND

Breast and ovarian cancers are the most prevalent cancers and one of the leading causes of death in Indian women. The healthcare burden of breast and ovarian cancers and the rise in mortality rate are worrying and stress the need for early detection and treatment.

METHODS

We performed amplicon sequencing of 144 cases who had breast/ovarian cancer disease (total 137 cases are patients and seven are tested for BRCA1/2 carrier) Using our custom designed gene panel consisting of 14 genes, that are associated with high to moderate risk of breast and ovarian cancers. Variants were called using Torrent Variant Caller and were annotated using ThermoFisher's Ion Reporter software. Classification of variants and their clinical significance were identified by searching the variants against ClinVar database.

RESULTS

From a total of 144 cases, we were able to detect 42 pathogenic mutations in [40/144] cases. Majority of pathogenic mutations (30/41) were detected in BRCA1 gene, while (7/41) pathogenic mutations were detected in BRCA2 gene, whereas, (2/41) pathogenic mutations were detected in TP53 gene and BRIP1, PALB2, and ATM genes respectively. So, BRCA genes contributed 88.09% of pathogenic mutations, whereas non-BRCA genes contributed 11.91% of pathogenic mutations. We were also able to detect 25 VUS which were predicted to be damaging by in silico prediction tools.

CONCLUSION

Early detection of cancers in the Indian population can be done by genetic screening using customized multi-gene panels. Indications of our findings show that in the Indian population, apart from the common BRCA genes, there are other genes that are also responsible for the disease. High frequency mutations detected in the study and variants of uncertain significance predicted to be damaging by in silico pathogenicity prediction tools can be potential biomarkers of hereditary breast and ovarian cancer in Indian HBOC patients.

Population Screening for Inherited Predisposition to Breast and Ovarian Cancer

The discovery of genes underlying inherited predisposition to breast and ovarian cancer has revolutionized the ability to identify women at high risk for these diseases before they become affected. Women who are carriers of deleterious variants in these genes can undertake surveillance and prevention measures that have been shown to reduce morbidity and mortality. However, under current strategies, the vast majority of women carriers remain undetected until they become affected. In this review, we show that universal testing, particularly of the BRCA1 and BRCA2 genes, fulfills classical disease screening criteria. This is especially true for BRCA1 and BRCA2 in Ashkenazi Jews but is translatable to all populations and may include additional genes. Utilizing genetic information for large-scale precision prevention requires a paradigmatic shift in health-care delivery. To address this need, we propose a direct-to-patient model, which is increasingly pertinent for fulfilling the promise of utilizing personal genomic information for disease prevention.

Mutations analysis of BRCA1 gene in patients with breast cancer in South Khorasan province, East Iran

Background: Breast cancer (BC) is well-known as the most common malignancy and the first leading cause of cancer-related death among women worldwide. Evidence suggests that familial history and age are important risk factors for the development of this disease in Iran. Mutations in BRCA1 and BRCA2 genes are the cause of 5 to 10% of hereditary BC. Recent studies demonstrated that mutations in BRCA1 were observed in high-risk women with family histories of BC. However, to date, the mutations have not been elucidated in BC patients from east of Iran. The purpose of this study was to analyze BRCA1 mutations in BC patient from South Khorasan Province.

Methods: In the present study, 88 BC patients (11 positive family history) were screened for mutations in BRCA1. The analysis of BRCA1 was carried out by SSCP (single-strand conformation polymorphism) for shorter exons and direct sequencing in the case of longer ones.

Results: Twenty-eight of the patients (31.8%) had a synonymous mutation (c.4308T>C) in exon 13. A missense mutation (c. 4837A>G) was presented in exon 16 with a frequency of 56.8 %. In exon 11 three missense mutations were observed, and the frequency rate for c.3113A>G was 32.5%, for c.3119G>A was 5%, and the highest frequency belonged to c.3548A>G with 72.4% in familial BC and 45.4% in the non-familial group.

Conclusion: In our study, five mutations were found, but none of the founder mutations were identified in this population. Two missense mutations in exon 16 (56.8%) and in exon 11 (65%) had the highest frequency in South Khorasan Province.

Mutations in context: implications of BRCA testing in diverse populations

Cancer is a common non-communicable disease worldwide, although it exhibits differential population trends in incidence and mortality rates. The differences relate to population structure, environmental risk factors as well as health system organization. This article discusses the potential impact of genetic testing on population health, focusing in particular on the mutational spectrum of breast cancer susceptibility genes in diverse populations. We identify the need for improved access to, and increased investment in, comprehensive cancer risk assessment and genetic testing as well as cancer control measures that take into account lifestyle, environmental, and social factors in understudied minority groups.

Genetic epidemiology of ovarian cancer in the 22 Arab countries: A systematic review

Ovarian cancer (OC) is a common disease among Arabs, with one of the highest incidences in the world. OC is underdiagnosed, underreported, and mostly reported with breast cancer. This study aimed to conduct a systematic review to estimate the published knowledge about the genetic epidemiology of OC in the 22 Arab countries. Therefore, we systematically searched seven literature databases (Web of science, PubMed, Science Direct, ProQuest, Embase, Scopus, and Google scholar) from the time of inception until June 2018 to collect all the information related to the incidence and pathogenic mutations spectrum for OC among Arabs. Our search strategy identified 3645 studies, of which 44 studies met our inclusion criteria, which cover the past 25 years (1993-2018). OC incidence among Arabs ranged from a low of 0.9/100,000/year in Saudi Arabia to a high of 8.0/100,000/year in Sudan. The total number of OC patients captured was 802; of these, 53 and five families carry 22 mutations in BRCA1/2 genes. Of these, eight mutations were unique to the Arab populations, and five mutations were commonly circulated among Arabs (BRCA1: c.5266dupC, c.5095C>T, c.68_69delAG, and c.4041_4042delAG; BRCA 2 c.1310_1313delAAGA). The ratio of BRCA1 (77.3%) mutations was higher than BRCA2 mutations (22.7%). This is the first systematic review to focus on the genetic epidemiology of only OC as an understudied disease that is common among Arabs. This study is expected to serve as a platform for further well-controlled genetic epidemiological studies for OC in the Arab world.

POLD1 and POLE Gene Mutations in Jewish Cohorts of Early-Onset Colorectal Cancer and of Multiple Colorectal Adenomas

BACKGROUND

Germline mutations in the DNA polymerase genes POLD1 and POLE confer high risk for multiple colorectal adenomas and colorectal cancer. However, prevalence and the clinical phenotype of mutation carriers are still not fully characterized.

OBJECTIVE

The purpose of this study was to assess the prevalence of germline mutations and to describe the genotype-phenotype correlation in POLD1 and POLE genes in Jewish subjects with multiple colorectal adenomas and/or early-onset mismatch repair proficient colorectal cancers.

DESIGN

This study is a comparison of genetic and clinical data from affected and control groups.

SETTINGS

The study was conducted at a high-volume tertiary referral center.

PATIENTS

The study cohort included 132 subjects: 68 with multiple colorectal adenomas and 64 with early-onset mismatch repair proficient colorectal cancers. The control group included 5685 individuals having no colorectal cancer or colorectal adenomas.

MAIN OUTCOME MEASURES

Study and control subjects were tested for POLD1 and POLE mutations and a clinical correlation was assessed.

RESULTS

Eleven of the 132 study subjects (8.3%) carried either a POLD1 or a POLE mutation: 7 of 68 (10.3%) subjects with multiple colorectal adenomas and 4 of 64 (6.2%) subjects with early-onset mismatch repair proficient colorectal cancer. Three mutations were detected, showing statistical significance in frequency between study and control groups (p < 0.001). Eight of the 11 mutation carriers were Ashkenazi Jews carrying the same POLD1 mutation (V759I), implicating it as a possible low-to-moderate risk founder mutation. Phenotype of mutation carriers was notable for age under 50 at diagnosis, a propensity toward left-sided colorectal cancer, and extracolonic tumors (64%, 100%, and 27% of cases).

LIMITATIONS

The study cohort was limited by its relatively small size.

CONCLUSIONS

Germline mutations in POLD1 and POLE were found to be relatively frequent in our Jewish cohorts. Further studies are needed to clarify the importance of POLD1 and POLE mutations and to define the most suitable surveillance program for Jewish and other POLD1 and POLE mutation carriers. See Video Abstract at http://links.lww.com/DCR/A658.

The yield of full BRCA1/2 genotyping in Israeli high-risk breast/ovarian cancer patients who do not carry the predominant mutations

PURPOSE

BRCA1 and BRCA2 genotyping results have clinical implications for cancer risk assessment and targeted therapy. Current practice in Israel is to genotype for the predominant BRCA1/2 mutations first, followed by full gene analysis in eligible mutation-negative individuals. This work assessed the rate of non-predominant mutations in BRCA1/2 in ethnically diverse high-risk cases.

METHODS

Breast and/or ovarian cancer patients who tested negative for the predominant BRCA1/2 mutations were referred for comprehensive BRCA1/2 genotyping if calculated risk for carrying a BRCA mutation was ≥ 10%.

RESULTS

Of 1258 eligible patients, 41 (3.3%) carried one of 38 mutations: 3% of Ashkenazi Jews and 3.4% of mixed ethnicities. Detection rate was < 5% among patients diagnosed with cancer younger than 40 or with bilateral breast cancer, and was 5.5% of ovarian cancer patients. Three of the carriers (7.3%) carried gene rearrangements. Three mutations were reported in more than one case.

CONCLUSIONS

The overall yield of comprehensive BRCA1/2 testing in ethnically diverse high-risk Israeli individuals is 3.3%. This is lower than expected by probability models. A slightly higher rate of BRCA1/2 carriers was seen among ovarian cancer cases. These data should guide BRCA1/2 optimal testing strategy in Israel.

Association of BRCA1 Promoter Methylation with Breast Cancer in Asia: A Meta- Analysis

Objective:

The aim of this study was to determine the degree of association of BRCA1 promoter methylation with breast cancer in Asia.

Methods:

The study sample for the present meta-analysis was provided by published research articles on associations of BRCA1 promoter methylation with breast cancer in Asia accessed through databases on PubMed, ProQuest and EBSCO published between 1997 and November 2017. Pooled odds ratios (OR) were calculated with fixed and random-effect models. Data were processed using Review Manager 5.3 (RevMan 5.3).

Results:

Of a total of 475 articles, 11 studies were included in our systematic review with meta-analysis of relevant data. The results showed a highly significant association between BRCA1 promoter methylation with breast cancer in Asia (OR = 8.78 [95% CI 4.15-18.56, p < 0.00001]).

Conclusion:

This analysis confirmed association between BRCA1 promoter methylation and breast cancer in Asia. BRCA1 promoter assessment might be a predictive or diagnostic aid for breast cancer prediction.

Cost effectiveness of population based BRCA1 founder mutation testing in Sephardi Jewish women

BACKGROUND

Population-based BRCA1/BRCA2 founder-mutation testing has been demonstrated as cost effective compared with family history based testing in Ashkenazi Jewish women. However, only 1 of the 3 Ashkenazi Jewish BRCA1/BRCA2 founder mutations (185delAG[c.68_69delAG]), 5382insC[c.5266dupC]), and 6174delT[c.5946delT]) is found in the Sephardi Jewish population (185delAG[c.68_69delAG]), and the overall prevalence of BRCA mutations in the Sephardi Jewish population is accordingly lower (0.7% compared with 2.5% in the Ashkenazi Jewish population). Cost-effectiveness analyses of BRCA testing have not previously been performed at these lower BRCA prevalence levels seen in the Sephardi Jewish population. Here we present a cost-effectiveness analysis for UK and US populations comparing population testing with clinical criteria/family history-based testing in Sephardi Jewish women.

STUDY DESIGN

A Markov model was built comparing the lifetime costs and effects of population-based BRCA1 testing, with testing using family history-based clinical criteria in Sephardi Jewish women aged ≥30 years. BRCA1 carriers identified were offered magnetic resonance imaging/mammograms and risk-reducing surgery. Costs are reported at 2015 prices. Outcomes include breast cancer, ovarian cancer, and excess deaths from heart disease. All costs and outcomes are discounted at 3.5%. The time horizon is lifetime, and perspective is payer. The incremental cost-effectiveness ratio per quality-adjusted life-year was calculated. Parameter uncertainty was evaluated through 1-way and probabilistic sensitivity analysis.

RESULTS

Population testing resulted in gain in life expectancy of 12 months (quality-adjusted life-year = 1.00). The baseline discounted incremental cost-effectiveness ratio for UK population-based testing was £67.04/quality-adjusted life-year and for US population was $308.42/quality-adjusted life-year. Results were robust in the 1-way sensitivity analysis. The probabilistic sensitivity analysis showed 100% of simulations were cost effective at £20,000/quality-adjusted life-year UK and the $100,000/quality-adjusted life-year US willingness-to-pay thresholds. Scenario analysis showed that population testing remains cost effective in UK and US populations, even if premenopausal oophorectomy does not reduce breast cancer risk or if hormone replacement therapy compliance is nil.

CONCLUSION

Population-based BRCA1 testing is highly cost effective compared with clinical criteria-driven approach in Sephardi Jewish women. This supports changing the paradigm to population-based BRCA testing in the Jewish population, regardless of Ashkenazi/Sephardi ancestry.

The Genetics of Breast Cancer: What the Surgical Oncologist Needs to Know

This article summarizes the impact of germline predisposition to breast cancer on the surgical management of breast cancer and breast cancer risk. Surgical implications of germline predisposition to breast cancer are now more nuanced due to the application of increasingly more complicated next-generation sequencing-based tests. The rapid pace of change will continue to challenge paradigms for genetic cancer risk assessment, which can influence the medical and surgical management of breast cancer risk as well as strategies for screening and for risk reduction.

The origin of the p.E180 growth hormone receptor gene mutation

Laron syndrome, an autosomal recessive condition of extreme short stature, is caused by the absence or dysfunction of the growth hormone receptor. A recurrent mutation in the GHR gene, p.E180, did not alter the encoded amino acid, but activated a cryptic splice acceptor resulting in a receptor protein with an 8-amino acid deletion in the extracellular domain. This mutation has been observed among Sephardic Jews and among individuals in Ecuador, Brazil and Chile, most notably in a large genetic isolate in Loja, Ecuador. A common origin has been postulated based on a shared genetic background of markers flanking this mutation, suggesting that the Lojanos (and others) may have Sephardic (Converso) Jewish ancestry. Analysis of the population structure of Lojanos based on genome-wide analysis demonstrated European, Sephardic Jewish and Native American ancestry in this group. X-autosomal comparison and monoallelic Y chromosomal and mitochondrial genetic analysis demonstrated gender-biased admixture between Native American women and European and Sephardic Jewish men. These findings are compatible with the co-occurrence of the Inquisition and the colonization of the Americas, including Converso Jews escaping the Inquisition in the Iberian Peninsula. Although not found among Lojanos, Converso Jews also brought founder mutations to contemporary Hispanic and Latino populations in the BRCA1 (c.68_69delAG) and BLM (c.2207_2212delATCTGAinsTAGATTC) genes.

Targeted Resequencing of 30 Genes Improves the Detection of Deleterious Mutations in South Indian Women with Breast and/or Ovarian Cancers

BACKGROUND

We earlier used PCR-dHPLC for mutation analysis of BRCA1 and BRCA2. In this article we report application of targeted resequencing of 30 genes involved in hereditary cancers.

MATERIALS AND METHODS

A total of 91 patient samples were analysed using a panel of 30 genes in the Illumina HiScan SQ system. CLCBio was used for mapping reads to the reference sequences as well as for quality-based variant detection. All the deleterious mutations were then reconfirmed using Sanger sequencing. Kaplan Meier analysis was conducted to assess the effect of deleterious mutations on disease free and overall survival.

RESULTS

Seventy four of the 91 samples had been run earlier using the PCR-dHPLC and no deleterious mutations had been detected while 17 samples were tested for the first time. A total of 24 deleterious mutations were detected, 11 in BRCA1, 4 in BRCA2, 5 in p53, one each in RAD50, RAD52, ATM and TP53BP1. Some 19 deleterious mutations were seen in patients who had been tested earlier with PCR-dHPLC [19/74] and 5/17 in the samples tested for the first time, Together with our earlier detected 21 deleterious mutations in BRCA1 and BRCA2, we now had 45 mutations in 44 patients. BRCA1c.68_69delAG;p.Glu23ValfsX16 mutation was the most common, seen in 10/44 patients. Kaplan Meier survival analysis did not show any difference in disease free and overall survival in the patients with and without deleterious mutations.

CONCLUSIONS

The NGS platform is more sensitive and cost effective in detecting mutations in genes involved in hereditary breast and/or ovarian cancers.

Inherited breast cancer predisposition in Asians: multigene panel testing outcomes from Singapore

Genetic testing for germline mutations in breast cancer predisposition genes can potentially identify individuals at a high risk of developing breast and/or ovarian cancer. There is a paucity of such mutational information for Asians. Panel testing of 25 cancer susceptibility genes and BRCA1/2 deletion/duplication analysis was performed for 220 Asian breast cancer patients or their family members referred for genetics risk assessment. All 220 participants had at least one high-risk feature: having a family history of breast and/or ovarian cancer in first- and/or second-degree relatives; having breast and ovarian cancer in the same individual or bilateral breast cancer; having early-onset breast cancer or ovarian cancer (⩽40 years of age). We identified 67 pathogenic variants in 66 (30.0%) patients. Of these, 19 (28.3%) occurred in BRCA1, 16 (23.9%) in BRCA2, 7 (10.4%) in PALB2, 6 (9.0%) in TP53, 2 (3.0%) in PTEN, 2 (3.0%) in CDH1 and 15 (22.4%) in other predisposition genes. Notably, 47.8% of pathogenic variants were in non-BRCA1/2 genes. Of the 66 patients with pathogenic mutations, 63.6% (42/66) were under the age of 40 years. Family history of breast and/or ovarian cancer is enriched in patients with BRCA1/2 pathogenic variants but less predictive for non-BRCA1/2 related pathogenic variations. We detected a median of three variants of unknown significance (VUS) per gene (range 0–21). Custom gene panel testing is feasible and useful for the detection of pathogenic mutations and should be done in the setting of a formal clinical cancer genetics service given the rate of VUS.

Comprehensive spectrum of BRCA1 and BRCA2 deleterious mutations in breast cancer in Asian countries

Approximately 5%-10% of breast cancers are due to genetic predisposition caused by germline mutations; the most commonly tested genes are BRCA1 and BRCA2 mutations. Some mutations are unique to one family and others are recurrent; the spectrum of BRCA1/BRCA2 mutations varies depending on the geographical origins, populations or ethnic groups. In this review, we compiled data from 11 participating Asian countries (Bangladesh, Mainland China, Hong Kong SAR, Indonesia, Japan, Korea, Malaysia, Philippines, Singapore, Thailand and Vietnam), and from ethnic Asians residing in Canada and the USA. We have additionally conducted a literature review to include other Asian countries mainly in Central and Western Asia. We present the current pathogenic mutation spectrum of BRCA1/BRCA2 genes in patients with breast cancer in various Asian populations. Understanding BRCA1/BRCA2 mutations in Asians will help provide better risk assessment and clinical management of breast cancer.

Screening of 185DelAG, 1014DelGT and 3889DelAG BRCA1 mutations in breast cancer patients from North-East India

Around 1.35 million people of worldwide suffer from breast cancer each year, whereas in India, 1 in every 17 women develops the disease. Mutations of the Breast Cancer 1 (BRCA1) gene account for the majority of breast/ ovarian cancer families. The purpose of study was to provide a prevalence of BRCA1 germline mutations in the North-East Indian population. In relation to the personal and family history with the breast cancer, we found mutations in 6.25% and 12.5% respectively. Three mutations, 185DelAG, 1014DelGT and 3889DelAG, were observed in our North-East Indian patients in exons 2 and 11, resulting in truncation of the BRCA1 protein by forming stop codons individually at amino acid positions 39, 303 and 1265. Our results point to a necessity for an extensive mutation screening study of high risk breast cancer cases in our North-East Indian population, which will provide better decisive medical and surgical preventive options.

Prevalence of the BRCA1 c.68_69delAG (BIC: 185delAG) mutation in women with breast cancer from north-central Poland and a review of the literature on other regions of the country

AIM OF THE STUDY

Germline mutations in BRCA tumor suppressor genes are strongly associated with breast and ovarian cancer. The lifetime risk of these cancers in women with BRCA1 mutation is 84% and 27%, respectively. Studies on the prevalence of BRCA1 c.68_69delAG congenital mutation, the most frequent in Ashkenazi Jews, among women with breast cancer from north-central Poland and review of the literature on other regions of the country. Evaluation of the c.68_69delAG association with breast cancer risk, with respect to women's age at diagnosis and family history of cancer.

MATERIAL AND METHODS

252 women with breast cancer, without any of the mutations c.5266dupC, c.181T > G, or c.4034delA, regardless of histological type and family history of cancer. The mutation was detected using allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) assay and confirmed by sequence analysis.

RESULTS

The c.68_69delAG mutation was disclosed in one out of the 252 women (0.4%), who had been diagnosed with breast cancer at age 43. Family investigations revealed the presence of c.68_69delAG also in the patient's mother, diagnosed with breast cancer at age 68. Sequence analysis confirmed the heterozygous status of the mutation, and family investigation its hereditary character. In the group of families with breast cancer history 1.4% frequency of c.68_69delAG was shown.

CONCLUSIONS

Among families with breast cancer aggregation, originating from north-central Poland, c.68_69delAG is a rare BRCA1 alteration, similarly to other central regions of the country, investigated by other authors. However, in northern, north-western and south-western parts of Poland, it occurs 2-4 times more frequently than in our region.

Phenotypic and Molecular Characterization of MCF10DCIS and SUM Breast Cancer Cell Lines

We reviewed the phenotypic and molecular characteristics of MCF10DCIS.com and the SUM cell lines based on numerous studies performed over the years. The major signaling pathways that give rise to the phenotype of these cells may serve as a good resource of information when researchers in drug discovery and development use these cells to identify novel targets and biomarkers. Major signaling pathways and mutations affecting the coding sequence are also described providing important information when using these cells as a model in a variety of studies.

A comprehensive focus on global spectrum of BRCA1 and BRCA2 mutations in breast cancer

Breast cancer (BC) is the most common cancer of women all over the world. BRCA1 and BRCA2 gene mutations comprise the most important genetic susceptibility of BC. Except for few common mutations, the spectrum of BRCA1 and BRCA2 mutations is heterogeneous in diverse populations. 185AGdel and 5382insC are the most important BRCA1 and BRCA2 alterations which have been encountered in most of the populations. After those Ashkenazi founder mutations, 300T>G also demonstrated sparse frequency in African American and European populations. This review affords quick access to the most frequent alterations among various populations which could be helpful in BRCA screening programs.

Haplotype analysis of the 185delAG BRCA1 mutation in ethnically diverse populations

The 185delAG* BRCA1 mutation is encountered primarily in Jewish Ashkenazi and Iraqi individuals, and sporadically in non-Jews. Previous studies estimated that this is a founder mutation in Jewish mutation carriers that arose before the dispersion of Jews in the Diaspora ~2500 years ago. The aim of this study was to assess the haplotype in ethnically diverse 185delAG* BRCA1 mutation carriers, and to estimate the age at which the mutation arose. Ethnically diverse Jewish and non-Jewish 185delAG*BRCA1 mutation carriers and their relatives were genotyped using 15 microsatellite markers and three SNPs spanning 12.5 MB, encompassing the BRCA1 gene locus. Estimation of mutation age was based on a subset of 11 markers spanning a region of ~5 MB, using a previously developed algorithm applying the maximum likelihood method. Overall, 188 participants (154 carriers and 34 noncarriers) from 115 families were included: Ashkenazi, Iraq, Kuchin-Indians, Syria, Turkey, Iran, Tunisia, Bulgaria, non-Jewish English, non-Jewish Malaysian, and Hispanics. Haplotype analysis indicated that the 185delAG mutation arose 750-1500 years ago. In Ashkenazim, it is a founder mutation that arose 61 generations ago, and with a small group of founder mutations was introduced into the Hispanic population (conversos) ~650 years ago, and into the Iraqi-Jewish community ~450 years ago. The 185delAG mutation in the non-Jewish populations in Malaysia and the UK arose at least twice independently. We conclude that the 185delAG* BRCA1 mutation resides on a common haplotype among Ashkenazi Jews, and arose about 61 generations ago and arose independently at least twice in non-Jews.

Novel LOVD databases for hereditary breast cancer and colorectal cancer genes in the Chinese population

The Human Variome Project (HVP) is an international consortium of clinicians, geneticists, and researchers from over 30 countries, aiming to facilitate the establishment and maintenance of standards, systems, and infrastructure for the worldwide collection and sharing of all genetic variations effecting human disease. The HVP-China Node will build new and supplement existing databases of genetic diseases. As the first effort, we have created a novel variant database of BRCA1 and BRCA2, mismatch repair genes (MMR), and APC genes for breast cancer, Lynch syndrome, and familial adenomatous polyposis (FAP), respectively, in the Chinese population using the Leiden Open Variation Database (LOVD) format. We searched PubMed and some Chinese search engines to collect all the variants of these genes in the Chinese population that have already been detected and reported. There are some differences in the gene variants between the Chinese population and that of other ethnicities. The database is available online at http://www.genomed.org/LOVD/. Our database will appear to users who survey other LOVD databases (e.g., by Google search, or by NCBI GeneTests search). Remote submissions are accepted, and the information is updated monthly.

The impact of Converso Jews on the genomes of modern Latin Americans

Modern day Latin America resulted from the encounter of Europeans with the indigenous peoples of the Americas in 1492, followed by waves of migration from Europe and Africa. As a result, the genomic structure of present day Latin Americans was determined both by the genetic structure of the founding populations and the numbers of migrants from these different populations. Here, we analyzed DNA collected from two well-established communities in Colorado (33 unrelated individuals) and Ecuador (20 unrelated individuals) with a measurable prevalence of the BRCA1 c.185delAG and the GHR c.E180 mutations, respectively, using Affymetrix Genome-wide Human SNP 6.0 arrays to identify their ancestry. These mutations are thought to have been brought to these communities by Sephardic Jewish progenitors. Principal component analysis and clustering methods were employed to determine the genome-wide patterns of continental ancestry within both populations using single nucleotide polymorphisms, complemented by determination of Y-chromosomal and mitochondrial DNA haplotypes. When examining the presumed European component of these two communities, we demonstrate enrichment for Sephardic Jewish ancestry not only for these mutations, but also for other segments as well. Although comparison of both groups to a reference Hispanic/Latino population of Mexicans demonstrated proximity and similarity to other modern day communities derived from a European and Native American two-way admixture, identity-by-descent and Y-chromosome mapping demonstrated signatures of Sephardim in both communities. These findings are consistent with historical accounts of Jewish migration from the realms that comprise modern Spain and Portugal during the Age of Discovery. More importantly, they provide a rationale for the occurrence of mutations typically associated with the Jewish Diaspora in Latin American communities.

A deleterious BRCA1 mutation in a young Pakistani woman with metaplastic breast carcinoma

Metaplastic breast carcinoma (MBC) is a relatively rare subtype of breast cancer that encompasses a pathologically heterogeneous group of tumors. Pathogenic germ line mutations in the major breast cancer susceptibility genes BRCA1 and BRCA2 genes have been rarely found or described in MBC. We report the identification of the BRCA1 185delAG mutation in a 22-year-old Pakistani woman with triple-negative MBC that showed biphasic morphological features, including sarcomatous and malignant epithelial components. A comprehensive description of the clinical, histopathological, morphological, and immunohistochemical features of the tumor and the patient's treatment course is presented.

Complete BRCA mutation screening in breast and ovarian cancer predisposition families from a North-Eastern Romanian population

Breast cancer is the most common cancer in women worldwide, including Romania, where its incidence has increased significantly during the last decade. Ovarian cancer is the fourth leading cause of mortality by cancer in women. BRCA1 and BRCA2 are major cancer predisposition genes, responsible for a large percentage of hereditary breast and ovarian cancer (HBOC) families. We investigated 17 patients from unrelated HBOC families in north-eastern Romania, screening for mutations in BRCA1 and BRCA2 by mutation-specific PCR and by dideoxy sequencing. We identified four BRCA1 and two BRCA2 mutations in the 17 families. The overall mutation frequency was 41% (7/17; 5 BRCA1 and 2 BRCA2). Two mutations (BRCA1 c.2241dupC and BRCA2 c.8680C>T) were novel and not listed in the BIC database. Two recurrent BRCA1 mutations (c.5266dupC and c.181T>G), previously described among Ashkenazi Jewish and Eastern European populations, were also found. Two unclassified variants (UV) were found, one of which was novel (BRCA2 c.4589A>G). Medical follow-up for mutation carriers was implemented. Our study is the first molecular investigation of the role of the BRCA genes in breast and ovarian cancer in Romania.

Pathology of hereditary breast cancer

Background

Hereditary breast cancer runs in families where several members in different generations are affected. Most of these breast cancers are caused by mutations in the high penetrance genes BRCA1 and BRCA2 accounting for about 5% of all breast cancers. Other genes that include CHEK2, PTEN, TP53, ATM, STK11/LKB1, CDH1, NBS1, RAD50, BRIP1 and PALB2 have been described to be high or moderate penetrance breast cancer susceptibility genes, all contributing to the hereditary breast cancer spectrum. However, in still a part of familial hereditary breast cancers no relationship to any of these breast cancer susceptibility genes can be found. Research on new susceptibility genes is therefore ongoing.

Design

In this review we will describe the function of the today known high or moderate penetrance breast cancer susceptibility genes and the consequences of their mutated status. Furthermore, we will focus on the histology, the immunophenotype and genotype of breast cancers caused by mutations in BRCA1 and BRCA2 genes and the other high or moderate penetrance breast cancer susceptibility genes. Finally, an overview of the clinical implications of hereditary breast cancer patients will be provided.

Conclusion

This information leads to a better understanding of the morphological, immunohistochemical and molecular characteristics of different types of hereditary breast cancers. Further, these characteristics offer clues for diagnosis and new therapeutic approaches.

Presymptomatic breast cancer in Egypt: role of BRCA1 and BRCA2 tumor suppressor genes mutations detection

BACKGROUND

Breast cancer is one of the most common diseases affecting women. Inherited susceptibility genes, BRCA1 and BRCA2, are considered in breast, ovarian and other common cancers etiology. BRCA1 and BRCA2 genes have been identified that confer a high degree of breast cancer risk.

OBJECTIVE

Our study was performed to identify germline mutations in some exons of BRCA1 and BRCA2 genes for the early detection of presymptomatic breast cancer in females.

METHODS

This study was applied on Egyptian healthy females who first degree relatives to those, with or without a family history, infected with breast cancer. Sixty breast cancer patients, derived from 60 families, were selected for molecular genetic testing of BRCA1 and BRCA2 genes. The study also included 120 healthy first degree female relatives of the patients, either sisters and/or daughters, for early detection of presymptomatic breast cancer mutation carriers. Genomic DNA was extracted from peripheral blood lymphocytes of all the studied subjects. Universal primers were used to amplify four regions of the BRCA1 gene (exons 2,8,13 and 22) and one region (exon 9) of BRCA2 gene using specific PCR. The polymerase chain reaction was carried out. Single strand conformation polymorphism assay and heteroduplex analysis were used to screen for mutations in the studied exons. In addition, DNA sequencing of the normal and mutated exons were performed.

RESULTS

Mutations in both BRCA1 and BRCA2 genes were detected in 86.7% of the families. Current study indicates that 60% of these families were attributable to BRCA1 mutations, while 26.7% of them were attributable to BRCA2 mutations. Results showed that four mutations were detected in the BRCA1 gene, while one mutation was detected in the BRCA2 gene. Asymptomatic relatives, 80 (67%) out of total 120, were mutation carriers.

CONCLUSIONS

BRCA1 and BRCA2 genes mutations are responsible for a significant proportion of breast cancer. BRCA mutations were found in individuals with and without family history.

Haplotype of the C61G BRCA1 mutation in Polish and Jewish individuals

Recurring mutations in the BRCA1 gene are noted in some populations and represent either founder mutations or a mutational hot spot. The C61G*BRCA1 (c.181T>G) missense mutation is a pathogenic one commonly reported in Polish individuals. A Jewish non-Ashkenazi family (of Italian ancestry) was found to carry this mutation, and the present study aimed at evaluating whether this mutation represents a founder mutation or a mutational hot spot. To that end, multilocus allelotyping using five markers intragenic to and flanking the BRCA1 gene spanning a genomic region of approximately 1.5 Mbp was carried out in that family and in 20 unrelated Polish C61G*BRCA1 mutation carriers. Phasing was done using affected and unaffected Jewish family members. The alleles that compose the pathogenic, mutation-carrying intragenic BRCA1 haplotype of the Jewish mutation carriers were detected in 18/20 Polish mutation carriers. The two flanking markers farthest away showed more diversity, between and even within Polish individuals. In conclusion, the *BRCA1 missense mutation is a founder mutation that can be detected in geographically related populations.

Ashkenazi Parkinson's disease patients with the LRRK2 G2019S mutation share a common founder dating from the second to fifth centuries

The LRRK2 G2019S mutation is a major genetic determinant of Parkinson's disease (PD) across the world that occurs at an elevated frequency in Ashkenazi Jews. We determined the LRRK2 haplotypes in 77 G2019S carriers, mostly Ashkenazi Jews, and in 50 noncarrier Ashkenazi PD patients, using 16 genetic markers. A single haplotype was detected in all mutation carriers, indicating that these individuals share a common founder. Using a maximum-likelihood method, we estimate that Ashkenazi Jews with G2019S share a common ancestor who lived approximately 1,830 (95% CI 1,560-2,160) years ago, around the second century, after the second Jewish Diaspora.

Breast cancer risk associated with BRCA1 and BRCA2 in diverse populations

Germline mutations in the BRCA1 or BRCA2 tumour-suppressor genes are strong predictors of breast and/or ovarian cancer development. The contribution of these mutations to breast cancer risk within any specific population is a function of both their prevalence and their penetrance. Mutation prevalence varies among ethnic groups and may be influenced by founder mutations. Penetrance can be influenced by mutation-specific phenotypes and the potential modifying effects of the patient's own genetic and environmental background. Although estimates of both mutation prevalence and mutation penetrance rates are inconsistent and occasionally controversial, understanding them is crucial for providing accurate risk information to each patient.

Similar prevalence of founder BRCA1 and BRCA2 mutations among Ashkenazi and non-Ashkenazi men with breast cancer: evidence from 261 cases in Israel, 1976-1999

To evaluate the potential contribution of mutations in the BRCA1 and BRCA2 genes to male breast cancer (MBC), we expanded a previous study to screen a total of 261 Israeli men diagnosed with breast carcinoma. A total of 21 BRCA2 6174delT and 8 BRCA1 185delAG mutations were found. Similar frequencies of BRCA1 and BRCA2 mutation carriers were found among Ashkenazi (12.8%) and non-Ashkenazi Jews (9.1%). The combined prevalence of BRCA1/BRCA2 founder mutations among Ashkenazi Jewish men is slightly higher than for women, due to a higher frequency of BRCA2 mutations.

MDM2 SNP309 accelerates breast and ovarian carcinogenesis in BRCA1 and BRCA2 carriers of Jewish-Ashkenazi descent

A functional single nucleotide polymorphism in the promoter of the MDM2 gene, SNP309 (T>G), was recently found to accelerate tumorigenesis in early onset cancer cases. The SNP309 G-allele, introduces an SP1 site in the MDM2 promoter, resulting in enhanced MDM2 expression and activity. Thus, the G-allele of MDM2 SNP309 may represent a cancer predisposing allele. In this report, we assessed the role of SNP309 as a modifier of mutant BRCA1/BRCA2 alleles in inherited breast and ovarian cancer cases among Ashkenazi-Jewish (AJ) women. We genotyped several subsets of AJ women: 138 healthy women, 140 affected BRCA1/2 mutation carriers, 120 asymptomatic BRCA1/2 mutation carriers and 187 sporadic breast cancer patients. The frequency of GG genotype of SNP309 was similar among the different groups. Interestingly, we found almost three times higher frequency of the GG genotype among BRCA1/2 carriers diagnosed with breast and/or ovarian cancer at or under the age of 51 years compared with carriers diagnosed with cancer above the age of 51 years (allele frequency, P = 0.019). The GG genotype was significantly associated with breast and ovarian cancer risk among BRCA1/2 carriers diagnosed before 51 years of age (OR, 3.93; 95% CI, 1.41-10.90, P = 0.009). No significant difference in frequency of the GG genotype was observed between early and late onset non-carrier cancer patients and no association with risk, OR, 1.30; 95% CI 0.69-2.47, P = 0.419). These data suggest that MDM2 SNP309 acts as a modifier of mutant BRCA1/2 mutant alleles in AJ and may accelerate breast and ovarian carcinogenesis in genetically predisposed individuals.

Prevalence of BRCA1 and BRCA2 mutations in Pakistani breast and ovarian cancer patients

Among Asian countries, Pakistan has the highest rates of breast and ovarian cancer. To assess the contribution of the BRCA1 and BRCA2 germ line mutations to these high rates, we conducted the first study of 176 Pakistani breast and ovarian cancer patients, selected on family history and on age of diagnosis. Comprehensive BRCA mutation screening was performed using a range of techniques, including denaturing high-pressure liquid chromatography, single strand conformational polymorphism analysis and protein truncation test, followed by DNA sequencing. Thirty deleterious germ-line mutations were identified in the 176 families (17.0%), including 23 in BRCA1 and 7 in BRCA2. Four mutations, 185delAG, 185insA, S1503X and R1835X, were recurrent; these accounted for 52% of all identified BRCA1 mutations. Haplotype analyses suggested founder effects for 3 of these. The prevalence of BRCA1 or BRCA2 mutations was 42.8% for families with multiple cases of breast cancer, and was 50.0% for the breast/ovarian cancer families. The prevalence of mutations was 11.9% for single cases of early-onset breast cancer (< or =30 years) and was 9.0% for single cases of early-onset ovarian cancer (< or =45 years). Our findings show that BRCA mutations account for a substantial proportion of hereditary breast/ovarian cancer and early-onset breast and ovarian cancer cases in Pakistan.

Contribution of germline BRCA1 and BRCA2 sequence alterations to breast cancer in Northern India

Background

A large number of distinct mutations in the BRCA1 and BRCA2 genes have been reported worldwide, but little is known regarding the role of these inherited susceptibility genes in breast cancer risk among Indian women. We investigated the distribution and the nature of BRCA1 and BRCA2 germline mutations and polymorphisms in a cohort of 204 Indian breast cancer patients and 140 age-matched controls.

Method

Cases were selected with regard to early onset disease (≤40 years) and family history of breast and ovarian cancer. Two hundred four breast cancer cases along with 140 age-matched controls were analyzed for mutations. All coding regions and exon-intron boundaries of the BRCA1 and BRCA2 genes were screened by heteroduplex analysis followed by direct sequencing of detected variants.

Results

In total, 18 genetic alterations were identified. Three deleterious frame-shift mutations (185delAG in exon 2; 4184del4 and 3596del4 in exon 11) were identified in BRCA1, along with one missense mutation (K1667R), one 5'UTR alteration (22C>G), three intronic variants (IVS10-12delG, IVS13+2T>C, IVS7+38T>C) and one silent substitution (5154C>T). Similarly three pathogenic protein-truncating mutations (6376insAA in exon 11, 8576insC in exon19, and 9999delA in exon 27) along with one missense mutation (A2951T), four intronic alterations (IVS2+90T>A, IVS7+75A>T, IVS8+56C>T, IVS25+58insG) and one silent substitution (1593A>G) were identified in BRCA2. Four previously reported polymorphisms (K1183R, S1613G, and M1652I in BRCA1, and 7470A>G in BRCA2) were detected in both controls and breast cancer patients. Rare BRCA1/2 sequence alterations were observed in 15 out of 105 (14.2%) early-onset cases without family history and 11.7% (4/34) breast cancer cases with family history. Of these, six were pathogenic protein truncating mutations. In addition, several variants of uncertain clinical significance were identified. Among these are two missense variants, one alteration of a consensus splice donor sequence, and a variant that potentially disrupts translational initiation.

Conclusion

BRCA1 and BRCA2 mutations appear to account for a lower proportion of breast cancer patients at increased risk of harboring such mutations in Northern India (6/204, 2.9%) than has been reported in other populations. However, given the limited extent of reported family history among these patients, the observed mutation frequency is not dissimilar from that reported in other cohorts of early onset breast cancer patients. Several of the identified mutations are unique and novel to Indian patients.

Ashkenazi Jews and breast cancer: the consequences of linking ethnic identity to genetic disease

We explored the advantages and disadvantages of using ethnic categories in genetic research. With the discovery that certain breast cancer gene mutations appeared to be more prevalent in Ashkenazi Jews, breast cancer researchers moved their focus from high-risk families to ethnicity. The concept of Ashkenazi Jews as genetically unique, a legacy of Tay-Sachs disease research and a particular reading of history, shaped this new approach even as methodological imprecision and new genetic and historical research challenged it. Our findings cast doubt on the accuracy and desirability of linking ethnic groups to genetic disease. Such linkages exaggerate genetic differences among ethnic groups and lead to unequal access to testing and therapy.

The P1812A and P25TBRCA1and the 5164del4BRCA2Mutations: Occurrence in High-Risk Non-Ashkenazi Jews

Founder mutations in the BRCA1 and BRCA2 genes have been discovered in the Ashkenazic Jewish population, but a founder mutation(s) has not been discovered among non-Ashkenazi Jews (NAJ). Two BRCA1 mutations (P1812A, P25T), and a BRCA2 mutation (5164del4) have been detected in NAJ high-risk families. We studied the prevalence of these three mutations in 270 high-risk NAJ families, including 85 from Iraq/Iran, 67 from North Africa, 27 from Yemen, 50 from the Balkan region, and 41 with mixed ancestry. The three mutations were detected only in individuals related to the original families. We conclude that the P1812A and P25T BRCA1 and 5164del4 BRCA2 mutations are not likely to be founder mutations in NAJ high-risk families. We also assessed the pathogenicity of the BRCA1 P1812A mutation in vitro using reporter gene assays in yeast and mammalian cells. We found that the BRCA1 P1812A variant activity assays yielded a slightly reduced reporter gene activity. Thus, there is some uncertainty as to the pathogenicity of BRCA1 P1812A.

The 471delAAAG mutation and C353T polymorphism in the RNASEL gene in sporadic and inherited cancer in Israel

The rate of RNASEL 471delAAAG mutation was previously reported to be less than 7% in Ashkenazi prostate cancer patients. It seems plausible that the same mutation may also be involved in breast/ovarian cancer predisposition in Jewish individuals. To evaluate the role of this mutation in cancer predisposition, a total of 1011 individuals including 294 Jewish men with prostate cancer, 61 Ashkenazi women with ovarian cancer and 50 unaffected women, matched for age and ethnicity, were genotyped for sequence anomalies in a single RNASEL gene amplicon using DGGE and sequencing. Additionally, 209 Ashkenazi BRCA1/2 mutation carriers, 205 high-risk non-carriers matched for cancer type and age at diagnosis, and 192 healthy Ashkenazi women were screened, using DHPLC and restriction methods. The 471delAAAG mutation was detected in a single male with prostate cancer (1/294, 0.3%), in two ovarian cancer patients (2/141, 1.4%) and in one of 242 healthy controls (0.41%). An abnormal DHPLC profile identical to the one produced by the 471delAAAG mutation was noted in 23 additional women. The rate of this polymorphism was significantly elevated in high-risk non-carrier women (16/205; 7.8%) than in BRCA1/2 carriers (2/209; 1.0%) and controls (5/192; 2.6%) (chi = 11.670; P < 0.001). Sequence analysis disclosed a silent polymorphism in Valine at codon 118: c.353 C- > T.The 471delAAAG mutation occurs rarely in Israeli prostate and breast/ovarian cancer patients. A silent polymorphism in the RNASEL gene occurs more prevalently in high-risk Ashkenazi breast/ovarian cancer patients without a BRCA1/2 mutation.