No description available.

An estimated 5-10% of breast cancers are hereditary in nature and are due to the presence of a mutation in a breast cancer predisposition gene; approximately half of these cases possess a mutation in BRCA1 or BRCA2. Many BRCA1/BRCA2 mutations result in a truncated protein and hence are unequivocally disease-causing. However another class of mutations, the Variants of Unknown Significance (VUS), are more problematic as the effect of these mutations on protein function is unclear. The inability to classify these mutations as disease causing generates significant problems in risk evaluation, counseling and preventive care. Accordingly we sought to determine whether carriers of either a BRCA1 or BRCA2 mutation could be identified from non-carriers based on the gene expression patterns of non-cancerous cells. EBV-transformed lymphoblastoid cell lines established from BRCA1/BRCA2 mutation carriers and normal individuals were obtained through the NIH Breast Cancer Family Registries. Cell lines were mock-irradiated or treated with ionizing radiation (2 Gy). Following a recovery period of 6 hours total RNA was extracted and whole genome gene expression profiling was carried out. Molecular classifiers comparing the baseline expression profiles and the radiation-dependent expression profiles of BRCA1/BRCA2 mutation carriers to control individuals were created using a Support Vector Machine (SVM) coupled with a recursive feature removal (RFR) algorithm. Our results suggest that cell populations derived from BRCA1/BRCA2 mutation carriers display unique expression phenotypes from those of control individuals in both the basal and radiation-induced cases. In the task of classification using baseline expression, the BRCA1-classifier correctly classified 15/18 test samples using feature selection based on the training set only, while feature selection using the entire dataset (AD) improved classification to 16/18 samples. The BRCA2-baseline classifier correctly classified 13/17 and 14/17 (AD) samples, respectively. In the task of radiation-dependent classification, the BRCA1-IR classifier correctly classified 12/18 and 16/18 (AD) test samples respectively while the BRCA2-IR classifier correctly classified 13/17 and 16/17 (AD) test samples respectively. These results suggest the possibility of development of this assay into a novel hereditary breast cancer screening diagnostic able to accurately identify the presence of BRCA1 or BRCA2 mutations via a functional assay thereby improving patient outcomes. / Thesis (Master, Pathology & Molecular Medicine) -- Queen's University, 2008-03-27 15:38:19.269 / Canadian Breast Cancer Foundation-Ontario Chapter, Department of Pathology & Molecular Medicine Clinical Trust Fund

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-07-19T10:42:04Z No. of bitstreams: 2 Dissertação - Rebeca Mota Goveia - 2018.pdf: 2457051 bytes, checksum: 721dc25f2c29d54fc3bd4f0f13c5fc83 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-07-19T11:18:57Z (GMT) No. of bitstreams: 2 Dissertação - Rebeca Mota Goveia - 2018.pdf: 2457051 bytes, checksum: 721dc25f2c29d54fc3bd4f0f13c5fc83 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-07-19T11:18:57Z (GMT). No. of bitstreams: 2 Dissertação - Rebeca Mota Goveia - 2018.pdf: 2457051 bytes, checksum: 721dc25f2c29d54fc3bd4f0f13c5fc83 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Introduction: Breast cancer is the second most common cancer in the world, and the most common among women, only 5% to 10% are hereditary and half of them are caused by hereditary breast and ovarian cancer (HBOC) , caused by variations in the BRCA1 and BRCA2 genes. Objectives: The present study aimed to identify the prevalence of deletions and duplications in BRCA1 and BRCA2 genes in breast cancer patients in Goiás, Brazil. Materials and methods: We evaluated 46 breast cancer patients who met National Comprehensive Cancer Network (NCCN) criteria for HBOC syndrome screening. A 4 ml blood sample was collected for DNA extraction using commercial kit and the MLPA (Multiplex Ligation Dependent Probe Amplification) technique was performed using the SALSA MLPA P002 BRCA1 and SALSA MLPA P045 BRCA2 / CHECK2 kits. Results and discussion: The majority of the patients were female (97.83%) and the mean age of the patients was 37.52 years. In this group, 43.47% of the patients were younger than 35 years at the time of diagnosis and 35% of them were diagnosed with triple negative tumors. The most common molecular subtype was luminal A (46.2%) followed by triple negative tumors (28.20%). No patient was found with rearrangements in BRCA1. In the BRCA2 gene, one patient (2.12%) presented a false positive result for the heterozygous deletion of exon 27, which may have been caused by the presence of a small change in the probe binding region. Conclusion: This was the first study performed to analyze large deletions and duplications in patients from the central-western region of Brazil. We can conclude that the frequency of large deletions and duplications in the BRCA1 and BRCA2 genes in the Goian population is low. / Introdução: O câncer de mama é o segundo tipo de câncer mais freqüente no mundo, e o mais comum entre as mulheres, apenas 5% a 10% são hereditários e metade deles são causados ​​pela síndrome do câncer de mama e ovário hereditário (HBOC), causada por variações nos genes BRCA1 e BRCA2. Objetivos: O presente estudo teve como objetivo identificar a prevalência de deleções e duplicações nos genes BRCA1 e BRCA2 em pacientes com câncer de mama no estado de Goiás, Brasil. Materiais e métodos: Avaliamos 46 pacientes com câncer de mama que atenderam aos critérios do National Comprehensive Cancer Network (NCCN) para pesquisa da síndrome HBOC. Foi coletada uma amostra de sangue de 4 ml para extração de DNA usando kit comercial e a técnica MLPA (Multiplex Ligation Dependent Probe Amplification) foi realizada usando os kits SALSA MLPA P002 BRCA1 e SALSA MLPA P045 BRCA2 / CHECK2. Resultados e discussão: A maioria dos pacientes era do sexo feminino (97.83%) e a idade média dos pacientes era de 37,52 anos. Neste grupo 43.47% dos pacientes possuíam idade inferior a 35 anos no momento do diagnóstico sendo que 35% destes foram diagnosticados com tumores triplo negativo. O subtipo molecular mais comum foi o luminal A (46.2%) seguido de tumores triplo negativos (28.20%). Nenhum paciente foi encontrado com rearranjos no gene BRCA1. No gene BRCA2, um paciente (2,12%) apresentou um resultado falso positivo para a deleção em heterozigoze do éxon 27, fato que pode ter sido ocasionado pela presença de uma pequena alteração na região de ligação da sonda. Conclusão: Este foi o primeiro estudo realizado para análise de grandes deleções e duplicações em pacientes da região centro-oeste do Brasil. Podemos concluir que a frequência de grandes deleções e duplicações nos genes BRCA1 e BRCA2 na população goiana é baixa.

Identifying individuals with hereditary cancer predisposition can improve health outcomes for patients and their family members through early cancer detection and prevention strategies. Prior research about family sharing of genetic test results among those with hereditary breast cancer has overwhelmingly been limited to the BRCA1 and BRCA2 genes. The present study sought to compare family sharing behaviors in women with pathogenic BRCA variants to women with pathogenic variants in the more recently identified and characterized PALB2 gene. A total of 18 BRCA carriers and 13 PALB2 carriers were interviewed about family sharing practices using a semi-structured guide based on the Integrated Behavioral Model. Barriers and facilitators to family sharing were similar for both BRCA and PALB2 carriers, with logistical difficulties and emotional struggles related to anticipated negative reactions from relatives being the most salient barriers. The most important facilitators were: attitude that sharing enables health protection, provider recommendation, strong family relationships, confidence in sharing basic information, knowledge of what to share and how to share, and belief that sharing is highly important. Given similar attitudes, norms, and control beliefs related to family sharing, similar, but tailored interventions may be effective at increasing family disclosures among both groups. Such interventions should involve a discussion of patients’ attitudes towards sharing with healthcare providers to strengthen motivations and address barriers and provision of informational resources to increase confidence and knowledge. Family sharing resources should clearly specify which relatives need to be informed, why sharing is important, and how at-risk relatives may benefit.

No description available.

L’altération constitutionnelle des gènes BRCA1 et BRCA2 est détectée dans 20 à 30% des formes familiales de cancer du sein. La fréquence de mise en évidence d’une mutation BRCA2 selon des critères généalogiques reste modeste. La définition de caractéristiques tumorales communes aux tumeurs du sein survenant dans un contexte de prédisposition lié à BRCA2 a pour objectif l’identification de caractéristiques propres aux tumeurs BRCA2 permettant de mieux définir les indications de recherche de mutation de ce gène, et l’identification de facteurs impliqués dans la tumorigénèse des cancers du sein liés à BRCA2. L’étude des profils génomiques des tumeurs BRCA2 a caractérisé la délétion récurrente des bras longs des chromosomes 13 et 14. L’analyse supervisée des données d’expression entre les tumeurs BRCA2 et les tumeurs familiales BRCAX a identifié une signature spécifique des tumeurs BRCA2. Les exomes des chromosomes 13 & 14 pour 5 tumeurs informatives et leur ADN constitutionnel ont été séquencés afin d’identifier la ou les cibles des régions délétées. Cette analyse a permis la caractérisation de variants somatiques qui seront à étudier dans une large série de cas BRCA2 et contrôles pour conclure sur leur rôle dans la tumorigénèse liée à BRCA2.La caractérisation de pertes de matériel chromosomique spécifiques aux tumeurs BRCA2, rapportée dans plusieurs études, offre une perspective diagnostique avec le développement d’un test FISH utilisable en pratique clinique pour préciser les indications d’une recherche de mutation du gène BRCA2, mais suggère également la présence de gènes cibles candidats dont l’inactivation est requise lors de la cancérisation mammaire liée à BRCA2. / Germline BRCA1 and BRCA2 mutations account for 20-30% of familial breast cancer. The main indication for BRCA2 screening is a family history, but the mutation detection rate in patients selected this way is low. The identification of characteristics common to BRCA2-associated tumors would improve the criteria used to select patients for BRCA2 screening and could identify factors implicated in BRCA2-mutant breast cancer tumorigenesis. The analysis of BRCA2-mutant breast tumor genomic profiles identified deletions of chromosomes 13q and 14q as a common feature of BRCA2-tumors. Supervised gene expression analysis of BRCA2-mutant breast tumors and familial breast tumors without germline BRCA1 or BRCA2 mutations identified a specific BRCA2 gene signature. Exome sequencing of chromosomes 13q and 14q for 5 BRCA2-mutant tumors, and their associated germline DNA was performed in order to identify the target(s) of the specific genomic deletions in the BRCA2 tumors. This analysis characterized somatic variants that will be screened for in a larger cohort of BRCA2 and control tumors cases to explore their role in BRCA2-mutant breast cancer. Our study identified deletions of chromosomes 13q and 14q as a common feature of tumors with germline BRCA2 mutations, as has been observed in several previous studies. We suggest that FISH analysis for the deletion of these chromosomes would be a rapid and technically feasible first step to select tumors worth screening for germline BRCA2 mutations and we hypothesize that the inactivation of candidate genes located in these deleted regions allows the cell to resume division and progress thus contributing to tumorigenesis in BRCA2-mutant tumors.

Purpose: This study assessed effectiveness of five tools recommended by the US Preventive Services Task Force (USPSTF), designed to help primary care clinicians determine which unaffected patients to refer to genetics specialists for breast cancer risk assessment based on concerning family history. Design: This descriptive secondary analysis included 85 women aged 40-74. All participants had a first-degree female relative previously diagnosed with breast cancer who also had uninformative negative BRCA1/2 tests. Methods: Each pedigree was evaluated using the five tools including the Family History Screen-7 (FHS-7), Pedigree Assessment Tool (PAT), Manchester Scoring System, Referral Screening Tool (RST), and Ontario-Family History Assessment Tool (Ontario-FHAT). All five tools were applied to each study participant. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated to describe each tool’s ability to identify women with elevated risk as calculated by the Claus model. Receiver operating curves (ROC) were also plotted. Differences between areas under the curve (AUCs) for all possible pairs of tools were estimated through logistic regression to assess for differences in tool performance. Results: Claus calculations identified 14 women out of 85 whose lifetime risk of breast cancer was elevated at > 15%. Only two tools, the Ontario-FHAT and FHS-7, identified all 14 women with elevated risk, a sensitivity of 100%. The FHS-7 tool flagged all 85 participants, meaning its specificity was zero. The Ontario-FHAT flagged 59 participants as needing referral (specificity 36.2%) and had a negative predictive value (NPV) of 100%, indicating that if a woman was not found to need a referral to a genetics professional, it is likely she did not have an elevated lifetime risk of developing breast cancer. AUC values were not significantly different between tools (all p values > .05), and thus were not helpful in discriminating between the tools. Conclusion: In this population, the Ontario-FHAT out-performed other tools in terms of sensitivity and negative predictive value; however, low specificity and positive predictive value must be balanced against these findings. Thus, the Ontario-FHAT can help determine which women would benefit from referral to a genetics specialist.

En France, le cancer de sein héréditaire représente environ 2500 nouveaux cas par an, dont prés de la moitié est attribuée à la mutation du gène BRCA1.La recherche de la mutation par biologie moléculaire est un travail fastidieux, coûteux et long (8 mois d’attente environ actuellement).Pour trouver une solution à ce délai, nous avons étudié en immunohistochimie une série initiale de 21 anticorps répartis en 5 groupes : anticorps antiBrca1 du commerce, liés à la perte de l’inactivation de l’X, liés à la signature basale ou myoépithéliale, anticorps dits classiques du cancer de sein et finalement dérivés de signatures établies par cDNAarray.Nous avons utilisé la technique de’ tissue microarrays’ en utilisant de manière comparative une population de 27 cas de cancer de sein présentant une mutation germinale de BRCA1, et 81 cas témoins de cancer de sein sporadiques appariés à l’âge, ainsi qu’à des lignées cellulaires d’origine mammaires. Dans une deuxième série indépendante de validation nous avons appliqué les résultats obtenus de la première série sur 28 cas de cancer mammaire muté, et 28 cas du cancer mammaire sporadique dans les mêmes conditions initiales.Nos résultats montrent pour la première fois sur des tissus tumoraux une probabilité forte d’une association entre la mutation Brca1 et la perte de l’inactivation de l’X ; confirment la valeur de MS110 comme un bon anticorps prédictif d’une mutation de Brca1 ; apportent un argument pour une participation myoépithéliale dans l’oncogenèse de cancer mammaire Brca1 muté; appuient la relation entre ce dernier et les récepteurs RE,RP ainsi que P53 , Bcl2,Ki67 et valident en protéomique la valeur discriminant de CDC47 correspondant à un des gènes de la signature génomique.Après confirmation des mêmes résultats dans la série de validation, nous soutenons en analyses multivariés un modèle qui comprend seulement Grade 3, MS110, Lys27H3 négative, Vimentine et KI67 positive. Cette équation correspond à une sensibilité de 82% et spécificité de 81% et propose une approche rapide économique de pré- ciblage de la mutation Brca1 ; ce qui améliorait la prise en charge préventive, thérapeutique et globale des patients et leurs familles. / Family structure, lack of reliable information, cost and delay are usual concerns faced with when deciding to perform BRCA analyses. Testing the breast cancer tissues with four antibodies (MS110, lys27H3, Vimentin, KI67) in addition to grade evaluation enabled to rapidly select patients to carry out genetic testing identification. We constituted an initial breast cancer tissue micro-array, considered as a learning set comprising 27 BRCA1 and 81 sporadic tumours. A second independent validation set of 28 BRCA1 tumours was matched to 28 sporadic tumours using the same original conditions.We have investigated morphological parameters and 21 markers by immunohistochemistry.A logistic regression model was used to select the minimal number of markers providing the best model to predict BRCA1 status. The model was applied to the validation set to estimate specificity and sensibility.In the initial set, the univariate analysis identified 11 markers significantly associated with BRCA1 status. Then the best multivariate model comprised only Grade 3, MS110, Lys27H3, Vimentin and KI67. When applied to the validation set, BRCA1 tumours were correctly classified with a sensitivity of 83% and a specificity of 81%. The performance of this model was superior when compared to other profiles.This work offers a new rapid and economic method for the pre-screening of patients at high risk of being BRCA1mutation carriers, then to guide genetic testing, and finally to provide appropriate preventive measure, advices and treatments including targeted therapy to patients and their families.

Abstract Breast cancer is the most common cancer among women, and inherited predisposition is one of the major recognized causes of increased breast cancer risk. Only about half of the hereditary cases are explained by mutations in the known susceptibility genes, including the DNA damage response genes BRCA1, BRCA2 and PALB2, leaving the majority still uncovered. Identification of the missing genetic predisposing factors is important for more effective diagnostics and counseling of the risk families, and also for better understanding of the etiology and cellular characteristics of breast cancer. The first aim of this study was to investigate the cancer associations of six rare germline copy number variant (CNV) deletions, which were previously identified in breast cancer patients by a genome-wide microarray approach. The second aim was to identify novel susceptibility alleles, both protein-truncating variants and missense mutations, by next-generation sequencing (NGS) of nearly 800 DNA damage response genes in 189 hereditary breast cancer patients. The cancer-associations of all selected candidate alleles (6 CNVs, 39 protein-truncating variants and 35 missense mutations) were studied by case-control approach using DNA samples from several hundred breast cancer patients and healthy controls. The prevalence of the studied CNVs did not significantly differ between the cases and controls, but when studying the associations with specific clinical parameters, deletion in the CYP2C19 gene showed enrichment in the breast cancer patients with hormonally triple-negative tumors (p=0.021). As CYP2C19 functions in estrogen metabolism, the results indicate that disturbance of hormonal balance due to enzyme defects may predispose specifically to the estrogen receptor-negative subtype of breast cancer. Two protein truncating-variants, TEX15 c.7253dupT and FANCD2 c.2715+1G>A showed significant breast cancer association in the Northern Finnish cohort (p=0.018 and p=0.036, respectively). Similarly, two of the studied missense variants, RECQL p.Ile156Met (p=0.043) and POLG p.Leu392Val (p=0.010), were enriched in the breast cancer cases. Thus, this study provided novel connections between increased breast cancer risk and inherited mutations in TEX15, FANCD2 and POLG genes, and further supported the recently established role of RECQL as a breast cancer susceptibility gene. / Tiivistelmä Rintasyöpä on naisten yleisin syöpä, ja perinnöllinen alttius on yksi merkittävimmistä sairastumisriskiin vaikuttavista tekijöistä. Tunnetuimpia alttiustekijöitä ovat mutaatiot BRCA1-, BRCA2- ja PALB2-DNA-vauriovastegeeneissä, mutta ne yhdessä muiden altistavien geenimutaatioiden kanssa selittävät kuitenkin vain noin puolet perinnöllisistä rintasyöpätapauksista. Uusien alttiusgeenien löytäminen mahdollistaa tehokkaamman diagnostiikan ja korkeassa syöpäriskissä olevien sukujen perinnöllisyysneuvonnan, sekä auttaa ymmärtämään syvemmin rintasyövän etiologiaa ja syntymekanismeja solutasolla. Tämän väitöskirjan ensimmäisenä päämääränä oli tutkia tarkemmin aiemmin genominlaajuisella mikrosirumenetelmällä rintasyöpäpotilailta tunnistettujen harvinaisten perinnöllisten DNA-kopiolukuvariaatioiden (CNV) yhteyttä rintasyöpäriskiin. Toisena tavoitteena oli tunnistaa uusia rintasyöpäalttiusalleeleja, sekä proteiinitrunkaatioita että missense-mutaatioita, hyödyntämällä uuden sukupolven sekvensointitekniikkaa, jonka avulla tutkittiin mutaatioita lähes 800 DNA-vauriovastegeenistä 189 pohjoissuomalaiselta rintasyöpäpotilaalta. Valittujen kandidaattialleelien (6 deleetion aiheuttavaa CNV:tä, 39 proteiinitrunkaatiota ja 35 missense-mutaatiota) yhteyttä rintasyöpään tutkittiin tapaus-verrokkimenetelmällä käyttäen DNA-näytteitä usealta sadalta rintasyöpäpotilaalta ja terveeltä kontrollihenkilöltä. Tutkittujen CNV:iden esiintyvyydessä ei ollut merkitseviä eroja potilaiden ja kontrollien välillä, mutta tarkasteltaessa yhteyttä potilaiden kasvaimista saatuihin kliinisiin parametreihin, deleetio CYP2C19-geenissä oli yleisempi hormonaalisesti kolmoisnegatiivisissa rintatuumoreissa kuin muissa tuumorityypeissä (p=0.021). Koska CYP2C19 on estrogeenimetaboliaan osallistuva entsyymi, sen viallinen toiminta voi mahdollisesti altistaa erityisesti estrogeenireseptorinegatiiviselle rintasyövälle. Kaksi tutkituista proteiinitrunkaatioista, TEX15 c.7253dupT ja FANCD2 c.2715+1G>A, olivat rikastuneet perinnöllisessä rintasyöpäpotilasaineistossa verrattuna kontrolleihin (p=0.018 ja p=0.036). Myös kaksi missense-alleelia, RECQL p.Ile156Met (p=0.043) ja POLG p.Leu392Val (p=0.010), olivat yleisempiä rintasyöpäpotilailla. Tulokset osoittivat uuden yhteyden kohonneen rintasyöpäriskin ja perinnöllisten muutosten TEX15-, FANCD2- ja POLG-geenien välillä, sekä tukivat aiempia tutkimustuloksia, joiden mukaan RECQL on kohtalaisen riskin rintasyöpäalttiusgeeni.

Abstract Breast cancer is the most common malignancy in women and it is strongly influenced by hereditary risk factors. So far, most of the breast cancer-associated genes, including BRCA1/2, have been identified among those that encode proteins involved in DNA damage response (DDR) pathways. However, known genetic risk factors explain less than half of the familial risk of breast cancer. Identification of novel genes and mutations that predispose to breast cancer is important for the understanding of the mechanisms that contribute to the disease development and also for the identification of those individuals who are at high risk. The first aim of this study was to resolve the complementation groups of Finnish patients with Fanconi anemia (FA), which is a rare genetic disease caused by defects in a specific DDR pathway, and to study the role of the causative gene mutations in breast cancer predisposition. The second aim of this study was to identify novel breast cancer susceptibility genes and alleles by targeted next-generation sequencing (NGS) of multiple (~800) DDR related genes. In both approaches, the identified gene mutations were subjected to case-control association analysis utilizing DNA samples of over 1,000 breast cancer cases and 1,000 healthy controls. Investigation of the Finnish FA patients revealed six different disease-causing mutations in three different genes (FANCA, FANCG and FANCI). All of the studied mutations were recurrent in the Finnish population but did not associate with breast cancer. Targeted NGS identified three novel potential breast cancer susceptibility genes. A significant enrichment of TEX15 c.7253dupT and FANCD2 c.2715+1G>A mutations was observed among the hereditary breast cancer cases (P = 0.018 and P = 0.036, respectively). The strongest evidence was found for a Finnish founder mutation in MCPH1 (c.904_916del), which associated with breast cancer susceptibility both in familial (P = 0.003, OR 8.3) and unselected (P = 0.016, OR 3.3) patient cohorts. The tumor suppressive function of MCPH1 was indicated by the loss of the wild-type allele of MCPH1 in 40% of the studied carrier tumors. Furthermore, carriers exhibited a significant increase in genomic instability measured by spontaneous chromosomal rearrangements in peripheral blood lymphocytes. / Tiivistelmä Rintasyöpä on naisten yleisin syöpä. Sairastumisriskiin vaikuttavat voimakkaasti perinnölliset alttiustekijät, ja suurin osa tähän asti tunnistetuista rintasyöpäalttiusgeeneistä, kuten BRCA1/2, koodaa DNA-vauriovasteessa (DDR) toimivia proteiineja. Tunnistetut tekijät selittävät yhä kuitenkin vain alle puolet rintasyövän perinnöllisestä alttiudesta. Uusien alttiusgeenien tunnistaminen on tärkeää rintasyövän patomekanismien ymmärtämiseksi sekä korkean rintasyöpäriskin omaavien henkilöiden tunnistamiseksi. Tämän tutkimuksen tarkoituksena oli määrittää viallisesta DDR-signaalinsiirtoreitistä johtuvan Fanconin anemian (FA) komplementaatioryhmät suomalaisilta FA-potilailta sekä tutkia sairauden taustalla olevien geenimutaatioden yhteyttä rintasyöpäriskiin. Uusia alttiusgeenejä etsittiin myös kohdennetulla uuden sukupolven sekvensointimenetelmällä, jonka avulla tutkittiin yhtäaikaisesti n. 800 DDR-geeniä. Molemmilla lähestymistavoilla tunnistettujen geenimuutosten yhteyttä rintasyöpään selvitettiin tapaus-verrokkitutkimuksen avulla, jossa tutkittiin DNA-näytteitä yli tuhannelta rintasyöpäpotilaalta sekä yli tuhannelta terveeltä henkilöltä. Suomalaisten FA-potilaiden geenimuutoksia selvittävässä tutkimuksessa tunnistettiin yhteensä kuusi mutaatiota kolmessa eri geenissä (FANCA, FANCG ja FANCI). Kaikki tutkimuksessa tunnistetut mutaatiot olivat toistuvia suomalaisessa väestössä, mutta merkitsevää assosiaatiota näiden mutaatioiden ja rintasyöpäalttiuden välillä ei havaittu. DDR-geenien sekvensoinnin avulla tunnistettiin kolme uutta mahdollista rintasyöpäalttiusgeeniä. Tutkimuksessa havaittiin TEX15 c.7253dupT ja FANCD2 c.2715+1G>A mutaatioiden rikastuminen perinnöllisessä rintasyöpäaineistossa (P = 0.018 ja P = 0.036). Merkittävin yhteys rintasyöpäalttiuden kanssa todettiin MCPH1-geenin perustajamutaatiolle (c.904_916del). Tämä mutaatio assosioitui rintasyöpäalttiuden kanssa sekä perinnöllisessä (P = 0.003, OR 8.3) että valikoimattomassa potilasaineistossa (P = 0.016, OR 3.3). Useissa mutaatiokantajien tuumoreissa (40 %) normaali MCPH1 vastinalleeli oli hävinnyt, mikä viittaisi siihen, että MCPH1 toimii tuumorisuppressorina. Mutaatiokantajilla todettiin myös kohonnut määrä kromosomaalisia muutoksia veren periferaalisissa lymfosyyteissä, mahdollisesti kohonneeseen genomiseen epävakauteen liittyen.