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We describe 7 cases of abnormal karyotypes involving chromosomes Y and 15 in Ethiopian Beta Israel patients: 46,XX, der(15)t(Y;15)(q12;p12) and 46,XY,der(15)t(Y;15)(q12;p12). Six cases were incidentally found in amniocentesis performed for various indications; the indication for karyotyping in 1 case was recurrent abortions. To the best of our knowledge, this is the first report of this translocation in a specific ethnic group. We conclude that the derivative chromosome 15 with chromosome Y is probably a normal variant in Ethiopian Beta Israel occurring at an estimated frequency of 4/74 (5.4%). The prenatal diagnosis of this translocation in this population probably does not require further parental testing. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

It is presently unclear whether carriers ofBRCA1 mutations have an increased risk for colorectal cancer (CRC). To gain insight into this issue, 225 unselected Ashkenazi Jewish CRC patients were tested for the presence of the three common Jewish BRCA1/2 germline mutations: 185delAG and 5382insC (BRCA1) and 6174delT (BRCA2). A total of four carriers was found (4/225, 1.78%). This frequency is similar to the estimated normal Ashkenazi population frequency, thus suggesting that these specific mutations do not contribute to CRC predisposition. [ABSTRACT FROM AUTHOR]

Background: Surveillance of high-risk individuals for pancreatic ductal adenocarcinoma (PDAC) is recommended. This study aimed to determine the prevalence and outcomes of PDAC and its precursor lesions in BRCA1/2 pathogenic variants (PVs) carriers undergoing pancreatic surveillance., Methods: A retrospective multicenter cohort study of pancreatic surveillance outcomes in Israeli BRCA1/2 carriers preferably with a family history of PDAC., Results: A total of 180 asymptomatic carriers participated in the screening programs, including 57 (31.7%) with BRCA1 PVs, 121 (67.2%) with BRCA2 PVs, and 12 (6.6%) with PVs in BRCA1/2 and other genes, for a median follow-up period of 4 years. Ninety-one individuals (50.5%) fulfilled the International Cancer of the Pancreas Screening (CAPS) criteria for surveillance whereas 116 (64.4%) fulfilled the American College of Gastroenterology (ACG) criteria. There were four cases of adenocarcinoma and four cases of grade 1-neuroendocrine tumor (G1-NET). All were BRCA2 carriers, and two had no family history of PDAC. Three cancer patients were at resectable stages (IA, IIA, IIB) whereas one had a stage IIIB tumor. Of the G1-NET cases, one had surgery and the others were only followed. Success rate for detection of confined pancreatic carcinoma was thus 1.6% (three of 180) in the whole cohort, 1.6% (two of 116) among individuals who fulfilled ACG criteria and 2.2% (two of 91) in those fulfilling CAPS criteria for surveillance., Conclusions: Despite the low detection rate of PDAC and its' high-risk neoplastic precursor lesions among BRCA1/2 carriers undergoing pancreatic surveillance, 75% of cancer cases were detected at a resectable stage., (© 2023 American Cancer Society.)

Founder pathogenic variants (PVs) are prevalent in Israel. This study investigated the current practice of offering cancer patients two-step genetic testing, starting with targeted testing for recurring founder PVs, followed, if negative, by next-generation sequencing. A total of 2128 subjects with cancer or a positive family history underwent oncogenetic testing with a panel of 51 recurring PVs at a tertiary medical center in March 2020-January 2023. Those with a known familial PV (n = 370) were excluded from the analysis. Among the remainder, 128/1758 (7%) were heterozygous for at least one variant, and 44 (34%) carried a PV of medium-high penetrance (MHPV). Cancer was diagnosed in 1519/1758 patients (86%). The diagnostic yield of founder MHPV testing was 2% in cancer patients and 4% in healthy individuals with a positive family history. It was higher in Ashkenazi Jews than non-Ashkenazi Jews and Arabs, but not over 10% for any type of cancer, and it was significantly higher in younger (<40 years) than older (>50 years) individuals (7% vs. 1%). Eighty-four of the heterozygotes (66%), mostly Ashkenazi Jews, harbored a low-penetrance variant (LPV) not associated with the diagnosed cancer, usually APC c.3902T>A. These findings question the advantage of two-step testing. LPVs should not be included in targeted testing because this can lead to an overestimation of the yield, and their detection does not preclude further comprehensive testing.

Objective: To compare colorectal cancer (CRC) incidences in carriers of pathogenic variants of the MMR genes in the PLSD and IMRC cohorts, of which only the former included mandatory colonoscopy surveillance for all participants., Methods: CRC incidences were calculated in an intervention group comprising a cohort of confirmed carriers of pathogenic or likely pathogenic variants in mismatch repair genes (path&#95;MMR) followed prospectively by the Prospective Lynch Syndrome Database (PLSD). All had colonoscopy surveillance, with polypectomy when polyps were identified. Comparison was made with a retrospective cohort reported by the International Mismatch Repair Consortium (IMRC). This comprised confirmed and inferred path&#95;MMR carriers who were first- or second-degree relatives of Lynch syndrome probands., Results: In the PLSD, 8,153 subjects had follow-up colonoscopy surveillance for a total of 67,604 years and 578 carriers had CRC diagnosed. Average cumulative incidences of CRC in path&#95;MLH1 carriers at 70 years of age were 52% in males and 41% in females; for path&#95;MSH2 50% and 39%; for path&#95;MSH6 13% and 17% and for path&#95;PMS2 11% and 8%. In contrast, in the IMRC cohort, corresponding cumulative incidences were 40% and 27%; 34% and 23%; 16% and 8% and 7% and 6%. Comparing just the European carriers in the two series gave similar findings. Numbers in the PLSD series did not allow comparisons of carriers from other continents separately. Cumulative incidences at 25 years were < 1% in all retrospective groups., Conclusions: Prospectively observed CRC incidences (PLSD) in path&#95;MLH1 and path&#95;MSH2 carriers undergoing colonoscopy surveillance and polypectomy were higher than in the retrospective (IMRC) series, and were not reduced in path&#95;MSH6 carriers. These findings were the opposite to those expected. CRC point incidence before 50 years of age was reduced in path&#95;PMS2 carriers subjected to colonoscopy, but not significantly so., (© 2022. The Author(s).)

Background: Lynch syndrome is a rare familial cancer syndrome caused by pathogenic variants in the mismatch repair genes MLH1, MSH2, MSH6, or PMS2, that cause predisposition to various cancers, predominantly colorectal and endometrial cancer. Data are emerging that pathogenic variants in mismatch repair genes increase the risk of early-onset aggressive prostate cancer. The IMPACT study is prospectively assessing prostate-specific antigen (PSA) screening in men with germline mismatch repair pathogenic variants. Here, we report the usefulness of PSA screening, prostate cancer incidence, and tumour characteristics after the first screening round in men with and without these germline pathogenic variants., Methods: The IMPACT study is an international, prospective study. Men aged 40-69 years without a previous prostate cancer diagnosis and with a known germline pathogenic variant in the MLH1, MSH2, or MSH6 gene, and age-matched male controls who tested negative for a familial pathogenic variant in these genes were recruited from 34 genetic and urology clinics in eight countries, and underwent a baseline PSA screening. Men who had a PSA level higher than 3·0 ng/mL were offered a transrectal, ultrasound-guided, prostate biopsy and a histopathological analysis was done. All participants are undergoing a minimum of 5 years' annual screening. The primary endpoint was to determine the incidence, stage, and pathology of screening-detected prostate cancer in carriers of pathogenic variants compared with non-carrier controls. We used Fisher's exact test to compare the number of cases, cancer incidence, and positive predictive values of the PSA cutoff and biopsy between carriers and non-carriers and the differences between disease types (ie, cancer vs no cancer, clinically significant cancer vs no cancer). We assessed screening outcomes and tumour characteristics by pathogenic variant status. Here we present results from the first round of PSA screening in the IMPACT study. This study is registered with ClinicalTrials.gov, NCT00261456, and is now closed to accrual., Findings: Between Sept 28, 2012, and March 1, 2020, 828 men were recruited (644 carriers of mismatch repair pathogenic variants [204 carriers of MLH1, 305 carriers of MSH2, and 135 carriers of MSH6] and 184 non-carrier controls [65 non-carriers of MLH1, 76 non-carriers of MSH2, and 43 non-carriers of MSH6]), and in order to boost the sample size for the non-carrier control groups, we randomly selected 134 non-carriers from the BRCA1 and BRCA2 cohort of the IMPACT study, who were included in all three non-carrier cohorts. Men were predominantly of European ancestry (899 [93%] of 953 with available data), with a mean age of 52·8 years (SD 8·3). Within the first screening round, 56 (6%) men had a PSA concentration of more than 3·0 ng/mL and 35 (4%) biopsies were done. The overall incidence of prostate cancer was 1·9% (18 of 962; 95% CI 1·1-2·9). The incidence among MSH2 carriers was 4·3% (13 of 305; 95% CI 2·3-7·2), MSH2 non-carrier controls was 0·5% (one of 210; 0·0-2·6), MSH6 carriers was 3·0% (four of 135; 0·8-7·4), and none were detected among the MLH1 carriers, MLH1 non-carrier controls, and MSH6 non-carrier controls. Prostate cancer incidence, using a PSA threshold of higher than 3·0 ng/mL, was higher in MSH2 carriers than in MSH2 non-carrier controls (4·3% vs 0·5%; p=0·011) and MSH6 carriers than MSH6 non-carrier controls (3·0% vs 0%; p=0·034). The overall positive predictive value of biopsy using a PSA threshold of 3·0 ng/mL was 51·4% (95% CI 34·0-68·6), and the overall positive predictive value of a PSA threshold of 3·0 ng/mL was 32·1% (20·3-46·0)., Interpretation: After the first screening round, carriers of MSH2 and MSH6 pathogenic variants had a higher incidence of prostate cancer compared with age-matched non-carrier controls. These findings support the use of targeted PSA screening in these men to identify those with clinically significant prostate cancer. Further annual screening rounds will need to confirm these findings., Funding: Cancer Research UK, The Ronald and Rita McAulay Foundation, the National Institute for Health Research support to Biomedical Research Centres (The Institute of Cancer Research and Royal Marsden NHS Foundation Trust; Oxford; Manchester and the Cambridge Clinical Research Centre), Mr and Mrs Jack Baker, the Cancer Council of Tasmania, Cancer Australia, Prostate Cancer Foundation of Australia, Cancer Council of Victoria, Cancer Council of South Australia, the Victorian Cancer Agency, Cancer Australia, Prostate Cancer Foundation of Australia, Asociación Española Contra el Cáncer (AECC), the Instituto de Salud Carlos III, Fondo Europeo de Desarrollo Regional (FEDER), the Institut Català de la Salut, Autonomous Government of Catalonia, Fundação para a Ciência e a Tecnologia, National Institutes of Health National Cancer Institute, Swedish Cancer Society, General Hospital in Malmö Foundation for Combating Cancer., Competing Interests: Declaration of interests HL holds patents on intact PSA assays and is named on a patent for a statistical method to detect prostate cancer licensed to Arctic Partners and commercialised by OPKO Health, and has stock in Arctic Partners and OPKO Health and receives royalties from sales of the 4Kscore test. RAE has received speaker honoraria from Genitourinary-American Society of Clinical Oncology, The University of Chicago, European Society for Medical Oncology (paid by Bayer and Ipsen), and The Royal Marsden NHS Foundation Trust (with support from Janssen), and is a member of the AstraZeneca UK Limited Prostate Dx Advisory Panel external expert committee. No organisation had any role in the decision to publish or in the writing of the manuscript. All other authors declare no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Objectives: We evaluated the incidence of breast cancer and overall survival in a multi-center cohort of ovarian cancer patients carrying BRCA1/2 mutations in order to assess risks and formulate optimal preventive interventions and/or surveillance., Methods: Medical records of 502 BRCA1/2 mutation carriers diagnosed with ovarian cancer between 2000 and 2018 at 7 medical centers in Israel and one in New York were retrospectively analyzed for breast cancer diagnosis. Data included demographics, type of BRCA mutations, surveillance methods, timing of breast cancer diagnosis, and family history of cancer., Results: The median age at diagnosis of ovarian cancer was 55.8 years (range, 23.9-90.1). A third (31.5%) had a family history of breast cancer and 17.1% of ovarian cancer. Most patients (67.3%) were Ashkenazi Jews, 72.9% were BRCA1 carriers. Breast cancer preceded ovarian cancer in 17.5% and was diagnosed after ovarian cancer in 6.2%; an additional 2.2% had a synchronous presentation. Median time to breast cancer diagnosis after ovarian cancer was 46.0 months (range, 11-168). Of those diagnosed with both breast cancer and ovarian cancer (n = 31), 83.9% and 16.1% harbored BRCA1 and BRCA2 mutations, respectively. No deaths from breast cancer were recorded. Overall survival did not differ statistically between patients with an ovarian cancer diagnosis only and those diagnosed with breast cancer after ovarian cancer., Conclusion: The low incidence of breast cancer after ovarian cancer in women carrying BRCA1/2 mutations suggests that routine breast surveillance, rather than risk-reducing surgical interventions, may be sufficient in ovarian cancer survivors., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Germline pathogenic sequence variants (PSVs) in BRCA1 substantially increase risk for developing breast (BC) and ovarian cancer (OvC). Yet, incomplete penetrance suggests that modifier factors affect phenotypic expression of mutant BRCA1 alleles. Analysis of identical BRCA1 PSV carriers of diverse ethnicities may provide further evidence for modifier factors. Female carriers of the 185delAG BRCA1 PSV identified through high-risk clinics in Israel, and Manchester England from 1998-2018 were eligible. Data were retrieved from patients records and confirmed (in Israel) by cross referencing with the Israeli National Cancer Registry. Overall, 2503 female carriers were included: 1715 (71.4%) Ashkenazi Jews (AJ), 201 (8.3%) Iraqi Jews and 383 (15.9%) of mixed ethnicity. In 102 (4.2%) cases ethnicity could not be ascertained. Of Israeli AJ carriers 649 (37.8%), 256 (14.9%) and 62 (3.6%) were diagnosed with BC, OvC or both cancers, respectively. For the Iraqi Jews these frequencies were 76 (37.8%), 43 (21.4%), and 8 (3.98%), respectively. Age at diagnosis of BC in AJ and Iraqi Jews was 46.7 ± 12.3 years and 52.8 ± 12.2 years, respectively (p = 0.001). For OvC age at diagnosis for AJ was 53.5 ± 10.7 years and for Iraqi Jews 50.1 ± 8.8 years (p = 0.0027). No differences in these parameters were noted between English Jews (n = 110) and non-Jews (n = 32). Age at diagnosis of BC and OvC differs between AJ and Iraqi Jews who carry an identical BRCA1 PSV. This finding supports the existence of modifier factors that may be ethnic specific.

Background: Mutations in BRCA2 cause a higher risk of early-onset aggressive prostate cancer (PrCa). The IMPACT study is evaluating targeted PrCa screening using prostate-specific-antigen (PSA) in men with germline BRCA1/2 mutations., Objective: To report the utility of PSA screening, PrCa incidence, positive predictive value of PSA, biopsy, and tumour characteristics after 3 yr of screening, by BRCA status., Design, Setting, and Participants: Men aged 40-69 yr with a germline pathogenic BRCA1/2 mutation and male controls testing negative for a familial BRCA1/2 mutation were recruited. Participants underwent PSA screening for 3 yr, and if PSA > 3.0 ng/ml, men were offered prostate biopsy., Outcome Measurements and Statistical Analysis: PSA levels, PrCa incidence, and tumour characteristics were evaluated. Statistical analyses included Poisson regression offset by person-year follow-up, chi-square tests for proportion t tests for means, and Kruskal-Wallis for medians., Results and Limitations: A total of 3027 patients (2932 unique individuals) were recruited (919 BRCA1 carriers, 709 BRCA1 noncarriers, 902 BRCA2 carriers, and 497 BRCA2 noncarriers). After 3 yr of screening, 527 men had PSA > 3.0 ng/ml, 357 biopsies were performed, and 112 PrCa cases were diagnosed (31 BRCA1 carriers, 19 BRCA1 noncarriers, 47 BRCA2 carriers, and 15 BRCA2 noncarriers). Higher compliance with biopsy was observed in BRCA2 carriers compared with noncarriers (73% vs 60%). Cancer incidence rate per 1000 person years was higher in BRCA2 carriers than in noncarriers (19.4 vs 12.0; p =  0.03); BRCA2 carriers were diagnosed at a younger age (61 vs 64 yr; p =  0.04) and were more likely to have clinically significant disease than BRCA2 noncarriers (77% vs 40%; p =  0.01). No differences in age or tumour characteristics were detected between BRCA1 carriers and BRCA1 noncarriers. The 4 kallikrein marker model discriminated better (area under the curve [AUC] = 0.73) for clinically significant cancer at biopsy than PSA alone (AUC = 0.65)., Conclusions: After 3 yr of screening, compared with noncarriers, BRCA2 mutation carriers were associated with a higher incidence of PrCa, younger age of diagnosis, and clinically significant tumours. Therefore, systematic PSA screening is indicated for men with a BRCA2 mutation. Further follow-up is required to assess the role of screening in BRCA1 mutation carriers., Patient Summary: We demonstrate that after 3 yr of prostate-specific antigen (PSA) testing, we detect more serious prostate cancers in men with BRCA2 mutations than in those without these mutations. We recommend that male BRCA2 carriers are offered systematic PSA screening., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: BRCA1/2 mutation carriers have an increased risk of developing ovarian cancer, leading to the recommendation of risk-reducing salpingo-oophorectomy (RRSO) at 35-40 years of age. The role, if any, that BRCA mutations play in conferring uterine cancer risk, is unresolved., Method: Jewish Israeli women, carriers of one of the predominant Jewish mutations in BRCA1/2 from 1998 to 2016, were recruited. Cancer diagnoses were determined through the Israeli National Cancer Registry. Uterine cancer risk was assessed by computing the standardized incidence ratio of observed-to-expected number of cases, using the exact 2-sided P value of Poisson count., Results: Overall, 2627 eligible mutation carriers were recruited from 1998 to 2016, 2312 (88%) of whom were Ashkenazi Jews (1463 BRCA1, 1154 BRCA2 mutation carriers, 10 double mutation carriers). Among these participants, 1310 underwent RRSO without hysterectomy at a mean (± standard deviation) age of 43.6 years (± 4.4 years). During 32,774 women-years of follow up, 14 women developed uterine cancer, and the observed-to-expected rate of all histological subtypes was 3.98 (95% confidence interval [CI], 2.17-6.67; P < .001). For serous papillary (n = 5), the observed-to-expected ratio was 14.29 (95% CI, 4.64-33.34; P < .001), and for sarcoma (n = 4) it was 37.74 (95% CI, 10.28-96.62). These rates were also higher than those detected in a group of 1844 age- and ethnicity-matched women (53% with breast cancer)., Conclusion: Israeli BRCA1 or BRCA2 mutation carriers are at an increased risk for developing uterine cancer, especially serous papillary and sarcoma. These elevated risks of uterine cancer should be discussed with BRCA carriers., (© 2018 American Cancer Society.)

Multiple primary tumors (MPTs) affect a substantial proportion of cancer survivors and can result from various causes, including inherited predisposition. Currently, germline genetic testing of MPT-affected individuals for variants in cancer-predisposition genes (CPGs) is mostly targeted by tumor type. We ascertained pre-assessed MPT individuals (with at least two primary tumors by age 60 years or at least three by 70 years) from genetics centers and performed whole-genome sequencing (WGS) on 460 individuals from 440 families. Despite previous negative genetic assessment and molecular investigations, pathogenic variants in moderate- and high-risk CPGs were detected in 67/440 (15.2%) probands. WGS detected variants that would not be (or were not) detected by targeted resequencing strategies, including low-frequency structural variants (6/440 [1.4%] probands). In most individuals with a germline variant assessed as pathogenic or likely pathogenic (P/LP), at least one of their tumor types was characteristic of variants in the relevant CPG. However, in 29 probands (42.2% of those with a P/LP variant), the tumor phenotype appeared discordant. The frequency of individuals with truncating or splice-site CPG variants and at least one discordant tumor type was significantly higher than in a control population (χ 2 = 43.642; p ≤ 0.0001). 2/67 (3%) probands with P/LP variants had evidence of multiple inherited neoplasia allele syndrome (MINAS) with deleterious variants in two CPGs. Together with variant detection rates from a previous series of similarly ascertained MPT-affected individuals, the present results suggest that first-line comprehensive CPG analysis in an MPT cohort referred to clinical genetics services would detect a deleterious variant in about a third of individuals., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

This corrects the article DOI: 10.1038/bjc.2017.429.

Background: Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls) is an international consortium of 62 centres in 20 countries evaluating the use of targeted PCa screening in men with BRCA1/2 mutations., Objective: To report the first year's screening results for all men at enrollment in the study., Design, Setting and Participants: We recruited men aged 40-69 yr with germline BRCA1/2 mutations and a control group of men who have tested negative for a pathogenic BRCA1 or BRCA2 mutation known to be present in their families. All men underwent prostate-specific antigen (PSA) testing at enrollment, and those men with PSA >3 ng/ml were offered prostate biopsy., Outcome Measurements and Statistical Analysis: PSA levels, PCa incidence, and tumour characteristics were evaluated. The Fisher exact test was used to compare the number of PCa cases among groups and the differences among disease types., Results and Limitations: We recruited 2481 men (791 BRCA1 carriers, 531 BRCA1 controls; 731 BRCA2 carriers, 428 BRCA2 controls). A total of 199 men (8%) presented with PSA >3.0 ng/ml, 162 biopsies were performed, and 59 PCas were diagnosed (18 BRCA1 carriers, 10 BRCA1 controls; 24 BRCA2 carriers, 7 BRCA2 controls); 66% of the tumours were classified as intermediate- or high-risk disease. The positive predictive value (PPV) for biopsy using a PSA threshold of 3.0 ng/ml in BRCA2 mutation carriers was 48%-double the PPV reported in population screening studies. A significant difference in detecting intermediate- or high-risk disease was observed in BRCA2 carriers. Ninety-five percent of the men were white, thus the results cannot be generalised to all ethnic groups., Conclusions: The IMPACT screening network will be useful for targeted PCa screening studies in men with germline genetic risk variants as they are discovered. These preliminary results support the use of targeted PSA screening based on BRCA genotype and show that this screening yields a high proportion of aggressive disease., Patient Summary: In this report, we demonstrate that germline genetic markers can be used to identify men at higher risk of prostate cancer. Targeting screening at these men resulted in the identification of tumours that were more likely to require treatment., (Copyright © 2014 European Association of Urology. All rights reserved.)

The I1307K APC germline mutation is associated with an increased risk to colorectal cancer (CRC). Whether and to what extent the somatic features and the molecular pathways of cancer development in mutation carriers differ from colorectal cancer in noncarriers remains unknown. To gain insight into this issue, 52 Israeli patients with CRC, 24 of whom were I1307K APC mutation carriers, were analyzed. The expression pattern of genes known to be involved in the pathogenesis of sporadic CRC was assessed immunohistochemically: E-cadherin, beta-catenin, deleted in colon cancer (DCC), and p53. In addition, tumors were genotyped for somatic activating mutations in Ki-ras oncogene. Mutation carriers and noncarriers were comparable in age at diagnosis (64.3 +/- 10.1 years for carriers and 60.8 +/- 14.1 years for noncarriers), tumor location in the colon, and disease stages. Tumors of I1307K mutation carriers displayed positive p53 immunostaining and loss of beta-catenin, E-cadherin, and DCC expression more often compared with noncarriers, although none of these differences reached statistical significance. Mutation frequencies in the Ki-ras gene were similar in both groups. In conclusion, the molecular pathways in CRC in I1307K APC mutation carriers are seemingly similar to those of sporadic cases, but a larger study is clearly needed.

Colorectal cancers (CRC) among Israeli Arabs differ from those diagnosed in Jewish Israeli individuals in two manners: an earlier age of occurrence and a low frequency. These differences are unaccounted for and thus prompted us to perform genetic analysis in Israeli Arab CRC patients. Analysis included the major Hereditary non-polyposis colorectal cancer (HNPCC) genes and the APC I1307K mutation (MIM# 175100.0029). Twenty-five patients and 25 relatives from 24 unrelated families were clinically classified according to personal and familial cancer history. If MSI (microsatellite instability) was displayed in tumor tissue, patients underwent mutation analysis of the MSH2 and MLH1 genes using DGGE (denaturing gradient gel electrophoresis) and sequencing. MSI was detected in 9/21 of the tumors tested (43%). Two novel missense mutations were diagnosed among 11 fully analyzed patients: a change of A to G at position 380 in MSH2 (N127S), and a D601G mutation in MLH1. The I1307K mutation was detected in 8 families (8/24, 33.3%). This is the first report of genetic analysis in familial CRC associated genes among Israeli Arabs. We suggest that the I1307K mutation may contribute to CRC in Israeli Arabs and that inactivating mutations of MSH2 and MLH1 may not be a major cause for early onset CRC., (Copyright 2003 Wiley-Liss, Inc.)

Background: Deletion of the entire steroid sulfatase (STS) gene is the most common molecular defect in X-linked ichthyosis (XLI) patients. Usually, additional flanking sequences are also missing. The aim of this study was to estimate the extent of deletions in an ethnically heterogeneous population of Israeli XLI patients., Methods: Multiplex polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) techniques were applied in the analysis of blood samples of 24 patients and amniotic cells of seven affected fetuses from 22 unrelated families., Results: In 19 families, a large deletion of the 2-3 megabase was found. It included the whole STS gene and spanned adjacent areas up- and downstream between the loci DXS 1139 and DXS 1132. Two unrelated families of Iraqi ancestry had a partial deletion of the gene and its centromeric adjacent sequence. In another family, the telomeric end of the extragenic segment was only partially missing. Application of FISH on metaphase blood cells and interphase amniotic cells confirmed the diagnosis of XLI in all patients, except the three with partial intragenic deletion. In those cases, the remaining fraction of the gene was sufficient to provide a false negative result. Diagnosis of carriers and prenatal diagnosis in uncultured cells was applicable only by FISH., Conclusions: Our study revealed a remarkable heterogeneity in the deletion pattern among Israeli patients with XLI. This heterogeneity could not be attributed to specific ethnic groups because of the small size of the study group. More studies involving patients of various ancestries should be carried out. In addition, this study demonstrated the usefulness of the FISH technique in the prenatal diagnosis of fetuses with suspected XLI.