Risk Gene Mutations Research Articles

Targeted deep sequencing improves outcome stratification in chronic myelomonocytic leukemia with low risk cytogenetic features.

Clonal cytogenetic abnormalities are found in 20-30% of patients with chronic myelomonocytic leukemia (CMML), while gene mutations are present in >90% of cases. Patients with low risk cytogenetic features account for 80% of CMML cases and often fall into the low risk categories of CMML prognostic scoring systems, but the outcome differs considerably among them. We performed targeted deep sequencing of 83 myeloid-related genes in 56 CMML patients with low risk cytogenetic features or uninformative conventional cytogenetics (CC) at diagnosis, with the aim to identify the genetic characteristics of patients with a more aggressive disease. Targeted sequencing was also performed in a subset of these patients at time of acute myeloid leukemia (AML) transformation. Overall, 98% of patients harbored at least one mutation. Mutations in cell signaling genes were acquired at time of AML progression. Mutations in ASXL1, EZH2 and NRAS correlated with higher risk features and shorter overall survival (OS) and progression free survival (PFS). Patients with SRSF2 mutations associated with poorer OS, while absence of TET2 mutations (TET2wt) was predictive of shorter PFS. A decrease in OS and PFS was observed as the number of adverse risk gene mutations (ASXL1, EZH2, NRAS and SRSF2) increased. On multivariate analyses, CMML-specific scoring system (CPSS) and presence of adverse risk gene mutations remained significant for OS, while CPSS and TET2wt were predictive of PFS. These results confirm that mutation analysis can add prognostic value to patients with CMML and low risk cytogenetic features or uninformative CC.

A Pilot Study of Clinical Targeted Next Generation Sequencing for Prostate Cancer: Consequences for Treatment and Genetic Counseling

Targeted next generation sequencing (tNGS) is increasingly used in oncology for therapeutic decision-making, but is not yet widely used for prostate cancer. The objective of this study was to determine current clinical utility of tNGS for prostate cancer management. Seven academic genitourinary medical oncologists recruited and consented patients with prostate cancer, largely with unusual clinical and/or pathologic features, from 2013 to 2015. UW-OncoPlex was performed on formalin-fixed, paraffin-embedded (FFPE) primary tumors and/or metastatic biopsies. Results were discussed at a multidisciplinary precision tumor board prior to communicating to patients. FFPE tumor DNA was extracted for tNGS analysis of 194 cancer-associated genes. Results, multidisciplinary discussion, and treatment changes were recorded. Forty-five patients consented and 42 had reportable results. Findings included mutations in genes frequently observed in prostate cancer. We also found alterations in genes where targeted treatments were available and/or in clinical trials. 4/42 (10%) cases, change in treatment directly resulted from tNGS and multidisciplinary discussion. In 30/42 (71%) cases additional options were available but not pursued and/or were pending. Notably, 10/42 (24%) of patients harbored suspected germline mutations in moderate or high-penetrance cancer risk genes, including BRCA2, TP53, ATM, and CHEK2. One patient's tumor had bi-allelic MSH6 mutation and microsatellite instability. In total, 34/42 (81%) cases resulted in some measure of treatment actionability. Limitations include small size and limited clinical outcomes. Targeted NGS tumor sequencing may help guide immediate and future treatment options for men with prostate cancer. A substantial subset had germline mutations in cancer predisposition genes with potential clinical management implications for men and their relatives. Prostate 76:1303-1311, 2016. © 2016 Wiley Periodicals, Inc.

Incidence of germline mutations in risk genes including BRCA1/2 in consecutive ovarian cancer (OC) patients (AGO TR-1).

5538Background: Identification of families at risk for OC including recommendation for prophylactic surgery is the only effective method to reduce OC mortality. In addition, BRCA1/2 mutations are k...

Prevalence of somatic mutations in risk genes including BRCA1/2 in consecutive ovarian cancer patients (AGO-TR-1 study).

5544Background: The mutation status of BRCA1/2 and other ovarian cancer (OC) predisposition genes is a valuable prognostic and predictive factor and widely used for clinical decision making. Howeve...

380 Exome sequencing and rare variant analysis reveals multiple filaggrin mutations in Bangladeshi atopic eczema families and novel risk genes

380 Exome sequencing and rare variant analysis reveals multiple filaggrin mutations in Bangladeshi atopic eczema families and novel risk genes

The Association of SNAP25 Gene Polymorphisms in Attention Deficit/Hyperactivity Disorder: a Systematic Review and Meta-Analysis.

Attention deficit/hyperactivity disorder (ADHD) is one of the most highly heritable psychiatric disorders in childhood. The risk gene mutation accounts for about 60 to 90% cases. Synaptosomal-associated protein of 25kDa (SNAP-25) is a presynaptic plasma membrane protein which is expressed highly and specifically in the neuronal cells. A number of evidences have suggested the role of SNAP-25 in the etiology of ADHD. Notably, the animal model of coloboma mouse mutant bears a ∼2-cM deletion encompassing genes including SNAP25 and displays spontaneous hyperkinetic behavior. Previous investigators have reported association between SNPs in SNAP25 and ADHD, and controversial results were observed. In this study, we analyzed the possible association between six polymorphisms (rs3746544, rs363006, rs1051312, rs8636, rs362549, and rs362998) of SNAP25 and ADHD in a pooled sample of ten family-based studies and four case-control studies by using meta-analysis. The combined analysis results were significant only for rs3746544 (P = 0.010) with mild association (odds ratio (OR) = 1.14). And, the meta-analysis data for rs8636, rs362549, and rs362998 are the first time to be reported; however, no positive association was detected. In conclusion, we report some evidence supporting the association of SNAP25 to ADHD. Future research should emphasize genome-wide association studies in more specific subgroups and larger independent samples.

Behavioral phenotypes of genetic mouse models of autism.

More than a hundred de novo single gene mutations and copy-number variants have been implicated in autism, each occurring in a small subset of cases. Mutant mouse models with syntenic mutations offer research tools to gain an understanding of the role of each gene in modulating biological and behavioral phenotypes relevant to autism. Knockout, knockin and transgenic mice incorporating risk gene mutations detected in autism spectrum disorder and comorbid neurodevelopmental disorders are now widely available. At present, autism spectrum disorder is diagnosed solely by behavioral criteria. We developed a constellation of mouse behavioral assays designed to maximize face validity to the types of social deficits and repetitive behaviors that are central to an autism diagnosis. Mouse behavioral assays for associated symptoms of autism, which include cognitive inflexibility, anxiety, hyperactivity, and unusual reactivity to sensory stimuli, are frequently included in the phenotypic analyses. Over the past 10 years, we and many other laboratories around the world have employed these and additional behavioral tests to phenotype a large number of mutant mouse models of autism. In this review, we highlight mouse models with mutations in genes that have been identified as risk genes for autism, which work through synaptic mechanisms and through the mTOR signaling pathway. Robust, replicated autism-relevant behavioral outcomes in a genetic mouse model lend credence to a causal role for specific gene contributions and downstream biological mechanisms in the etiology of autism.

Symptom burden and its relationships with risk assessment and gene mutations in patients with primary myelofibrosis

Objective To study the symptom burden and its relationships with risk assessment and gene mutations in patients with primary myelofibrosis (PMF). Methods The symptom burden of patients with PMF was assessed in China-Japan Friendship Hospital from Mar 2012 to Apr 2015 by using MPN10 and also Dynamic International Prognostic Scoring System-plus (DIPSS-plus). Several related gene mutations in these patients were detected, and the relationships among the symptom burden, DIPSS-plus and gene mutations were analyzed. Results Among 36 patients, the symptom burden was assessed in 25 patients with average score 22.8. Fatigue and inactivity were occurred similarly in 22 cases (88 %), and fever and bone pain were only in 3 cases and 5 cases, respectively. According to DIPSS-plus, 35 patients were stratified into low (7 cases, 20.0 %), intermediate-1 (7 cases, 20.0 %), intermediate-2 (4 cases, 11.4 %) and high-risk groups (17 cases, 48.6 %). 25 patients completed MPN10. Total symptom score in intermediate-1 group was 28.7±6.2, which was higher than that in intermediate-2 group (11.0±2.9) (t = 2.579, P= 0.038), and the score in intermediate-2 group was lower than that in high-risk group (26.4±3.2) (t = 2.650, P = 0.024). Among 34 patients who received gene mutation detection, 25 cases (73.52 %) were identified as JAK2 mutation, and others were CALR, ASXL1, U2AF1, SRSF2, TET2, SETBP1 and UTX mutations. The incidence of TET2 mutation had significant difference between low-/intermediate-risk group and high-risk group (P = 0.022). The symptom score of patients who carried 3 or more mutations was significantly higher than that of less 3 mutations (P = 0.011). Conclusions The symptom burden of patients with PMF may reflect the heterogeneity and prognostic difference of PMF, and could be associated with DIPSS-plus risk stratification and the number of gene mutations. TET2 mutation is probably associated with PMF progress. Key words: Primary myelofibrosis; Symptom burden; Risk assessment; Gene mutation

Low-dose alemtuzumab in refractory/relapsed chronic lymphocytic leukemia: Genetic profile and long-term outcome from a single center experience.

Relapsed/refractory chronic lymphocytic leukemia (CLL) represents a clinical challenge, in particular when high risk gene mutations occur. In this setting, alemtuzumab was recognized to be effective. This retrospective study evaluates long-term efficacy and tolerability of low-dose alemtuzumab in relapsed/refractory CLL and correlates clinical outcome with biological feature. Sixty-two consecutive patients (median age 68 years) were evaluated; alemtuzumab was administered 30 mg weekly for up to 18 weeks. Among the patients included in the analysis, 37% were fludarabine-refractory, 33.3% carried a TP53 disruption, 14.8% a NOTCH1 mutation and 9% a SF3B1 mutation. Overall response rate (ORR) was 61.3% (complete remission 25.8%). After a median follow-up of 43 months, overall survival (OS) and progression free survival (PFS) were 43.1 and 15 months, respectively; while ORR was 77.8% for patients carrying TP53 disruptions (OS 33.8 months) and 43.5% for fludarabine-refractory patients (OS 30 months). Noteworthy, long-term survivors (OS ≥ 36 months) were 54.8%. None of the biological poor risk factors negatively impacted on ORR, PFS and OS. Grade ≥3 cytopenia occurred in 24.2% patients, 6.5% experienced a grade ≥3 non-CMV infection and no grade ≥3 CMV-event occurred. In conclusion, low dose-alemtuzumab is safe and effective in relapsed/refractory CLL, also in a long-term follow-up and high-risk genetic subgroups.

Abstract 2739: Transcontinental characterization of the Hispanic BRCA1 3450del4 breast cancer founder mutation

Abstract Breast cancer (BC) is the most commonly diagnosed cancer among women, with 1 in every 7 women in the U.S. developing BC in their lifetime. While BC may not be the leading cause of cancer incidence in many minority populations, such as Hispanics, it is the leading cause of cancer death, highlighting a cancer disparity. Moreover, the contribution of mutations in BC susceptibility genes remains poorly investigated in Hispanic populations. To begin to address these voids, we screened Colombian BC patients for common BRCA1 and BRCA2 mutations using the KASP genotyping system. Strikingly, 27 of 722 unselected cases (4%) harbored the same BRCA1 3450del4 mutation. Clinical data and family history indicate that these individuals originate from a distinct geographic region in Colombia, Neiva. Significantly, 10% of the unselected BC cases in Neiva and the surrounding region harbor the 3450del4 mutation, potentially representing one of the most profound founder effects reported in human populations. Interesting, this BRCA1 mutation has also been reported in other countries, including Portugal, Spain, and Chile. To determine whether this mutation stems from a single origin, mutation carriers from each of these countries (n = 26), along with mutation carriers from Colombia (n = 27), were subjected to the Affymetrix Axiom Human UK Biobank Array (>800 thousand markers). Haplotypes in which the BRCA1 mutation resides were estimated by SHAPEIT, and pairwise segmental sharing was determined using GERMLINE. Our data suggest that the mutation carriers, although from different countries and continents, share a core haplotype, likely to have originated from Spain. Additionally, the mutation seems to be fairly new to Colombia, with individuals sharing up to a 40Mb haplotype comprising the mutation. We are currently estimating the age of the mutation using the bioinformatic software DMLE+, which exploits the rate of linkage disequilibrium decay due to recombination. By understanding the prevalence of mutations in known breast cancer risk genes in minority populations, cancer disparities can be better addressed and breast cancer screening can be improved. Furthermore, these findings have direct implications in robust and cost-effective targeted screening in regions where there is a high prevalence of the BRCA1 3450del4 mutation. Citation Format: Anna Marie De Asis Tuazon, Carolina Ramirez, Mabel Bohorquez, Rodrigo Prieto, Paul Lott, Angel Criollo, Ana Estrada, Gillbert Mateus, Alejandro Velez, Justo Ramirez, COLUMBUS Consortium, Manuel Teixeira, Ana Vega, Conxi Lazaro, Eva Tornero, Cristina Martinez, Mar Infante, Miguel De La Hoya, Orland Diez, Pilar Carvallo, Magdalena Echeverry, Luis Carvajal-Carmona. Transcontinental characterization of the Hispanic BRCA1 3450del4 breast cancer founder mutation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2739. doi:10.1158/1538-7445.AM2015-2739

Abstract P4-12-04: Clinical evaluation of multigene testing for hereditary breast and ovarian cancer

Abstract Background: Advances in DNA sequencing technology have fueled the development of multigene panels for hereditary cancer testing. While such assays are potentially both practical and affordable for routine clinical genetic testing, there remains uncertainty regarding their proper application and interpretation. Among the unanswered questions are which patients are appropriate candidates for such expanded testing; what is the likelihood that finding deleterious variants will alter risk assessment and management, and what is the prevalence of variants of unknown significance (VUS) that may create uncertainty for providers and anxiety for patients. Methods: 821 patients who met NCCN guidelines for BRCA1/2 testing for hereditary breast/ovarian cancer (HBOC) were prospectively recruited at two major academic medical centers. These patients received traditional BRCA1/2 tests as part of their clinical care and also were later tested for a panel of 29 known cancer risk genes. This panel also re-tested BRCA1/2. Both sequence changes and deletions/duplications were reported, and the panel-testing laboratory was blind to the earlier results. Panel testing results were validated by comparison with the earlier data or by independent testing using established technologies. Family history information was collected directly by genetic counselors. Results: 13.8% of the patients carried BRCA1 or BRCA2 mutations, with >99% concordance between the traditional and panel results for these two genes. 53 (7.6%) of the BRCA1/2-negative patients carried mutations in other cancer risk genes. Some of these findings confer a high risk for breast/ovarian cancer (e.g. TP53), while others (i.e. CHEK2, BRIP1, PALB2, RAD51C, CDKN2A, ATM, and NBN) confer a moderate increase in risk. 10 of these 55 patients were positive for genes involved in Lynch syndrome (MLH1, MSH2, MSH6, and PMS2), although breast and ovarian cancer are not uniformly accepted as part of this syndrome. 40% of these patients were heterozygous carriers of pathogenic variants in MUTYH, which have a less clear impact on breast/ovarian cancer, although this rate (3%) is higher than the expected carrier frequency in this population. About 60% of patients had one or more VUS in the 29 genes. The rate of VUS was highly gene dependent, with ATM, APC, and PTCH1 providing the largest number. A small but significant subset of patients did not have personal or family histories consistent with the classical presentation of their identified mutation. Nevertheless, a majority of the non-BRCA1/2 findings would have prompted consideration of a management change for the tested patient even considering the personal and family cancer history. Conclusions: Multigene panel testing for hereditary cancer risk assessment increased the yield of findings with potential clinical impact for almost 8% of patients. This is consistent with prior data from our laboratory and others. This study, carried out in a uniform clinical practice setting and with data collected directly by health care providers, provides a representative view of the benefit from such testing in an unselected patient population. Citation Format: Leif Ellisen, Allison Kurian, Stephen Lincoln, Andrea Desmond, Meredith Mills, Kristen Shannon, Michelle Gabree, Michael Anderson, Yuya Kobayashi, Federico Monzon, James Ford. Clinical evaluation of multigene testing for hereditary breast and ovarian cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-12-04.

Prostate-specific antigen velocity as a predictive biomarker in a prospective prostate cancer screening study (IMPACT study).

16 Background: We retrospectively assessed the clinical application of Prostate Specific Antigen Velocity (PSA V) in the IMPACT study (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in men at higher genetic risk and controls). This is a case-control prostate cancer (PrCa) screening study for men with a known genetic predisposition to PrCa; participants with a single PSA reading above 3ng/ml are offered diagnostic TRUS prostate biopsies (PB). Methods: We calculated PSA velocity (PSA V) using all three validated methods, including the arithmetic mean, the linear regression and the first and last readings equations. Pearson chi-square test was used to compare PSA V between four genetic groups: BRCA1 carriers and BRCA1 negative controls and BRCA2 carriers and BRCA2 negative controls. Results: PSA V data were evaluated in 191 men who underwent a PB with a total of 57 PrCas diagnosed. PSA V using both a threshold of 0ng/ml/year and 0.75ng/ml/year in any of the three methods was not predictive of PrCa diagnosis in BRCA1/2 controls and BRCA1 carriers. Conversely, BRCA2 carriers with a PSA V over 0.75ng/ml/year (by linear regression) were 5 times more likely to be diagnosed with PrCa [95%CI=1.5-14; p=0.003]. Interestingly PSA V using linear regression was predictive of clinically significant tumours as defined by Gleason Score (GS) >= 7. Regardless of their genetic status, men with a PSA V over 0.75/ng/ml/year were 3 times more likely to have a clinically significant PrCa [95% CI: 1.006-11.107; p=0.045] whereas men with a BRCA2 mutation were 12 times more likely [95%CI: 1.1-98; p=0.039]. Conclusions: PSA V is an important tool for identifying which men with a BRCA2 mutation would benefit from a prostatic biopsy and could be incorporated into a predictive model, along with the total PSA value. PSA V also predicts for tumour aggressiveness regardless of genetic predisposition, but more so for those with a known high risk gene mutation. Clinical trial information: NCT00261456.

Minimal Residual Disease by Multiparametric Flow Cytometry Predicts Relapse Free Survival better than Over-Expression of WT1 and BAALC in Acute Myeloid Leukemia

Background: Improved molecular and immunophenotypic characterization of AML offers the opportunity to define markers in individual patients which can be used to monitor minimal residual disease (MRD). Immunophenotypic analyses are based on the multiparametric flow cytometry (MPFC) detection of leukemia-associated immunophenotypes. The most useful molecular prognostic markers implicated in AML characterization are NPM1 mutations, FLT3 ITD, CEBPA mutations, MLL -PTD, RUNX1 and ASXL1 mutations. Deregulated expression of genes have also been identified as prognostic markers eg BAALC, WT1 and ERG. In this study, gene mutations (NPM1, FLT3, CEBPA, MLL-PTD), gene expression (WT1 and BAALC)and immunophenotyping were prospectively assessed to detect MRD.Methods: Diagnostic Marrow/peripheral blood samples from 98 AML patients (excluding AML-M3) were included between March 2012 and July 2014. Patients received standard induction chemotherapy with daunorubicin 60 mg/m2 for 3 days and cytosine arabinoside 100 mg/m2 iv for 7 days. Marrow was done 21-28 days after start of induction chemotherapy for assessment of morphology, MPFC and molecular markers. If marrow was in remission (CR), then patients received 1st consolidation therapy with 18 gm/m2 of cytosine arabinoside (HiDAC). Marrow was repeated 21-28 days after 1st consolidation chemotherapy for assessment of same parameters as above. Patients then received 2 more HiDAC or underwent allogeneic transplant according to cytogenetic risk. Cytogenetic analyses were performed using standard techniques of chromosome banding and FISH. All cases were divided into three cytogenetic risk groups (i.e. good, intermediate and poor) based on NCCN guidelines. Immunophenotyping was done using 8 color MPFC. The same panel of antibodies was used to characterize the leukemic cells at diagnosis, post induction and post consolidation. MRD was calculated as a percentage of abnormal leukemic cells per total nucleated cells. cDNA synthesis and quantitative real time PCR (RQ-PCR) assays for WT1 and BAALCwere carried out according to Europe Against Cancer guidelines. Mutation profiling was carried out by capillary electrophoresis and direct DNA sequencing methods as described previously. Chi-square method was used to detect any association between risk groups and gene mutations. Probabilities of relapse-free survival (RFS) were estimated using Kaplan-Meier method. Univariate comparisons of RFS for potential prognostic markers (molecular and MPFC) were made using log-rank test.Results: Of 98 patients enrolled in this prospective study, 86 patients completed induction and 59 patients 3 courses of HiDAC. The median age was 27 years (range 15-58). Based on cytogenetic risk groups 24.4%, 47% and 28.6% were good, intermediate and poor risk cases respectively. Twelve patients died during induction due to sepsis and 16 patients were refractory to induction chemotherapy. Baseline frequencies of FLT3-ITD, MLL-PTD, NPM1-type A and CEBPA gene mutations were 20.4%, 10.2%, 20.4% and 25.5% respectively. The biallelic (TAD1 and ZIP mutations) and monoalleleic CEBPA mutations were found in 4.1% and 21.4% patients respectively. No significant association was found between different risk groups and gene mutations except NPM1-type A mutations were associated with good risk group (P=0.015). MRD by RQ-PCR for BAALC/WT1 and MPFC was assessed after post induction and post first consolidation therapy. There was one log reduction in mean copy number of WT1 (5312 vs 430) and BAALC (19648 vs 3298) between diagnosis and post consolidation samples. No significant differences were found between high expressors of WT1/BAALC and RFS. MPFC analyses revealed that 48% of post induction samples were MRD positive (range: 0.05-38%, mean 6.6%) Similarly, 53% of post consolidation samples were MRD positive (range: 0.01-85%, mean 10.9%). Univariate analysis showed that MRD positivity by MPFC at post induction (RFS at 1.5 years- 85% vs 30%, P=0.012) and post consolidation (RFS at 1.5 years- 90% vs 42%, P=0.015) was associated with poor RFS. Patients without MLL-PTD mutation showed better RFS (P=0.003) as compared to mutated cases and TAD2positivity at post induction showed a trend to better RFS (P=0.097).Conclusion: Our results suggest that MRD by MPFC predicts RFS more accurately than over-expression of WI1 and BAALC. DisclosuresNo relevant conflicts of interest to declare.

Abstract 1292: Identification of BRCA1 and BRCA2 founder mutations in population isolates from Colombia

Abstract Breast cancer (BC) is the most common malignancy in women. Germline mutations in breast cancer risk genes, such as BRCA1 and BRCA2, account for a large portion of hereditary breast cancer families. The contribution of mutations in breast cancer susceptibility genes has been poorly investigated in minority populations, such as in Hispanics from South America. While mutations in BRCA1 and BRCA2 display a heterogeneous mutation spectrum, specific mutations often occur in population isolates. Using the KASP genotyping technology, we screened 476 unselected Colombian breast cancer patients for three common BRCA1 and one BRCA2 founder mutations in the Hispanic population. The BRCA2 c.2806_2809delAAAC founder mutation was identified in 3 of the 476 BC cases (0.6%). Strikingly, 24 out of 476 cases (5.0%) harbored the BRCA1 founder mutation c.3331_3334delCAAG, which has also been reported in Southern European populations, including Spain and Portugal. The clinical data and family history of these patients have highlighted a distinct geographic region from where these cases originate. This finding potentially represents one of the most remarkable founder effects reported in human populations. To date the arrival of the BRCA1 c.3331_3334delCAAG mutation to Colombia, we are completing haplotype analysis of the patients and their families, along with BC cases from Spain and Portugal that harbor the same mutation. Interestingly, haplotype analyses of our BC cases have revealed a haplotype larger than 3.5 cM. In the future, we aim to perform haplotype analysis of family members of the mutation carriers and BC cases from Portugal and Spain to further study the haplotype around this BRCA1 mutation, which will allow us to date the origin of the mutation. By understanding the prevalence of mutations in known breast cancer risk genes in minority populations, cancer disparities can be better addressed and breast cancer screening can be improved. Furthermore, the ability to identify such strong founder effects highlights an advantage of using this Colombian population isolate in facilitating the identification of novel BC risk genes. Citation Format: Anna Marie D. Tuazon, Carolina Ramírez, Mabel Bohorquez, Rodrigo Prieto, Jorge Castro, Gilbert Mateus, Alejandro Velez, Magdalena Echeverry, Luis G. Carvajal-Carmona. Identification of BRCA1 and BRCA2 founder mutations in population isolates from Colombia. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1292. doi:10.1158/1538-7445.AM2014-1292

Risk factors for high-titer inhibitor development in children with hemophilia A: results of a cohort study.

Among the discussed risk factors for high-titre inhibitor (HRI) development in patients with hemophilia A (HA) are high dose FVIII replacement therapy and use of recombinant FVIII concentrates (rFVIII). The aim of this study was to evaluate the aforementioned risk factors for HRI development in children with hemophilia A ≤2%. About 288 ascertained PUPs (Israel and Germany) were followed after initial HA diagnosis over 200 exposure days. Inhibitor-free survival, hazard ratios (HR), and 95% confidence intervals (CIs) were calculated. Adjustment was performed for factor VIII concentrates, median single dose over the first three months of treatment, first FVIII administration before the age of three months, presence of risk HA gene mutations, “intensive treatment moments” and “year of birth” (proxy for different treatment periods). HRI occurred in 71/288 children (24.7%). In multivariate analysis adjusted for “year of birth”, underlying risk gene mutations (HR/CI: 2.37/1.40–3.99), FVIII dose, measured per one IU increase per kgbw (HR/CI: 1.05/1.04–1.07), and first FVIII administration before the age of three months showed a significant impact on HR development. The risk of HRI development was similar for recombinant or plasmatic FVIII products. Children at risk should be treated with carefully calculated lower dose regimens, adapted to individual bleeding situations.

Translational animal models of autism and neurodevelopmental disorders

Autism is a neurodevelopmental disorder whose diagnosis is based on three behavioral criteria: unusual reciprocal social interactions, deficits in communication, and stereotyped repetitive behaviors with restricted interests. A large number of de novo single gene mutations and chromosomal deletions are associated with autism spectrum disorders. Based on the strong genetic evidence, mice with targeted mutations in homologous genes have been generated as translational research tools. Mouse models of autism have revealed behavioral and biological outcomes of mutations in risk genes. The field is now poised to employ the most robust phenotypes in the most replicable mouse models for preclinical screening of novel therapeutics.

GWAS markers in diagnostics of breast cancer risk

Breast cancer belongs to the most common malignancy diagnosed in women. The major inherited susceptibilities to breast cancer are germline mutations in mutations in high risk genes, eg. BRCA1, BRCA2, BRIP, PALB2, RAD51C, RAD51D (5-10%), mutations in moderate risk genes, eg. CHEK2, ATM, NBS1 (10-20%) which however, explain only a small number of breast cancer cases. The latter are alterations in low risk genes and other possible changes in genome, eg. constitutional methylations of BRCA1. Genome – Wide Association Study (GWAS) was thought to help in identification of low risk alleles associated with the risk of particular disease. Up to know 14 GWAS conducted on Caucasian and 6 GWAS on Asian population (http://www.genome.gov/gwastudies/index.cfm?pageid=26525384#searchForm) have been performed on breast cancer cases and 21 variants associated with modest risk of BC (OR <1.3) have been identified. In 2005 have been initiated Breast Cancer Association Consortium (BCAC), an international multidisciplinary forum of investigators interested in the inherited risk of breast cancer. The aim of the consortium is to combine data from many studies in order to identify genes/SNPs and provide a reliable assessment of the breast cancer risks. Currently the BCAC gathers 69 centers from 29 countries, including Poland, and has access to demographic, clinical and epidemiological data from over 76,000 breast cancer patients and 83,000 unaffected women. In GWAS performed by BCAC 14 SNPs have been identified to be associated with modest risks of breast cancer(per-allele ORs<1.3). The aim of this study was to assess usefulness of SNPs identified in BCAC GWAS in diagnostics of breast cancer risk in Polish population. We found that 6 out of 14 SNPs identified in BCAC GWAS were associated with breast cancer risk in Polish patients. Four additional SNPs have been found to be associated with moderate risk of breast cancer in Polish study. Overall, out of 10 SNPs strongest in Polish study 3 seem to be valuable markers for breast cancer diagnostics in Poland: OR 1.91, 95%CI 1.39-2.65, p 0.0001 for carriers of 2 risk alleles and OR 3.2, 95%CI 1.87-5.47, p<0.0001 for carriers of 3 risk allele.

A Predictive Model for the Development of High-Responding Inhibitor In Children with Severe and Moderate Hemophilia A- Results of a Multicenter Cohort Study

AbstractAbstract 710 Background:Pediatric cohort studies in previously untreated [PUPs] children with hemophilia A [HA] identified potential risk factors for clinical meaningful inhibitor development [IH], among them HA severity < 1%, high risk gene mutations [HRS], high dose FVIII replacement therapy [HD] and use of recombinant FVIII concentrates [rFVIII]. The aim of the present study was to develop a simple score to rate inhibitor development in HA children. Patients and methods:184 consecutively ascertained PUPs [enrollment between 1982 and 2008] with HA [severity < 5%] followed over a period of 200 exposure days were randomly selected into two groups [G1; G2] of 92 patients each. Three variables [HRS: 2 points], [HD: median single dose > 30 IU/kgbw within 8 to 12 weeks after therapy start] and [rFVIII] 1 point each, were incorporated into a risk assessment model, which was i) evaluated in patient group G1 [pilot cohort: patients not included in the CANAL study] and ii) validated in the second group [G2: confirmation cohort]. The risk discrimination cut-off was calculated using two independent statistical methods [ROC-analysis: MedCalc 11.0.0; CART regression tree: CART 6.0]. In addition, model specific cumulative IH-free survival [Cox regression analysis: hazard ratio (HR) and 95% confidence interval (CI)], negative predictive values [NPV], sensitivity and specificity were calculated. In Cox regression analysis adjustment was performed for i) age at first symptomatic bleed [proxy for early start of prophylaxis], ii) severity of factor VIII-deficiency, and iii) for treatment periods [1982-2008: divided into 3 to 5 year intervals]. Results:The risk discrimination cut-off in the pilot cohort G1 was calculated as “2”. Model sensitivity was 78.8 % and specificity was 49.8% respectively. In the confirmation cohort G2 seventeen children with HA developed a high responding IH [18.5%]: 16 out of 52 in children with a risk score > 2 [30.8%] and one out of 40 with a risk score < 2 [2.5%: p<0.001]. Compared to children with a risk score < 2 the cumulative IH-free survival in HA patients with a risk score > 2 was significantly reduced with an adjusted HR [CI] of 11.2 [1.5-83.5]. The corresponding NPV to rule out a high responding IH development in the confirmation cohort was 92% [80.5-98.5]. Conclusion:The model is able to rule out the development of high responding IH in white children with HA < 5% with good discriminative ability. Thus the model can be instrumental to individualize treatment strategies in HA patients. The score needs to be validated in other populations to test its generalizability. Disclosures:No relevant conflicts of interest to declare.

Synergistic effects of environmental risk factors and gene mutations in Parkinson’s disease accelerate age‐related neurodegeneration

As Parkinson's disease appears to be a multifactoral disorder, the use of animal models to investigate combined effects of genetic and environmental risk factors are of great importance especially in the context of aging which is the single major risk factor for the disorder. Here, we assessed the combined effects of neonatal iron feeding and environmental paraquat exposure on age-related nigrostriatal degeneration in transgenic mice expressing the A53T familial mutant form of human α-synuclein within these neurons. We report here that A53T α-synuclein mice exhibit greater susceptibility to paraquat. Increased oral intake of iron in the neonatal period leads to a progressive age-related enhancement of dopaminergic neurodegeneration associated with paraquat neurotoxicity. Furthermore, neurodegeneration associated with these combined genetic and environmental risk factors could be attenuated by systemic treatment with the bioavailable antioxidant compound EUK-189. These data suggest that environmental factors previously identified as contributors to neurodegeneration associated with sporadic Parkinson's disease may also be candidates for observed variations in symptoms and disease progression in monogenic forms and that this may mechanistically involve increased levels of oxidatively-induced post-translational nitration of α-synuclein.

Breast cancer gene expression profile in young women who are noncarriers of BRCA1/2 mutations with and without familial history.

1538 Background: Breast cancer (BC) in young women is associated with worse prognosis and positive family history of breast and/or ovarian cancer with risk gene mutations, particularly BRCA gene germline mutations. However mutations in the BRCA1/2 genes explain only 10% of BC cases diagnosed before 40 years. Little is known about the genetic basis of early-onset non carriers of BRCA1/2 familial or non-familial cases but aggressive tumor characteristics may be derived from specific oncogenic pathways. Based on these facts, our assumption was that in young (≤ 35 years) patients (pt), with or without familial history, molecular random events may modulate pathways involved in carcinogenesis. Methods: We evaluated gene expression profile in Brazilian young women with and without BC familial history, excluding those with BRCA 1/2 mutations. Thirty one pt with maximum 35 years were included, 50% with ER(-) tumors, 11 and 20 pt reported positive FH(+) and negative FH(-) familial history (NCCN criteria) for BC can...