Genetic changes are hallmarks of cancer development involving the activation and/or inactivation of oncogenes and tumour suppressor genes, respectively. In non-melanoma skin cancer (NMSC) development, the initiation of genetic mutations results from exposure to solar ultraviolet radiation. Non-melanoma skin cancers are comprised of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Several related cutaneous lesions also exist, of which solar keratoses (SK) are widely accepted as a precursor dysplasia to SCC development. The study of recurrent genetic changes present within NMSC and SK should help reveal causative mutations in skin cancer development. Such analysis could also elucidate links in the genetic similarity of these dysplasia. The rapid screening of numerical changes in DNA sequence copy number throughout the entire genome has been made possible by the advent of comparative genomic hybridisation (CGH). This technique enables the identification of net gains and loss of genetic material within a tumour DNA sample. Chromosomal regions of recurrent gain or loss identify loci containing putative oncogenes and tumour suppressor genes, respectively with potential roles in NMSC tumourigenesis. Used in conjunction with tissue microdissection and universal degenerate PCR techniques this can enable the elucidation of aberrations in small histologically distinct regions of tumour. Such a technique can utilize archival material such as paraffin embedded tissue, which is the major source of neoplastic material available for cancer research. This study used the CGH technique to investigate aberrations in BCC, SCC and SK samples. The screening of copy number abnormalities (CNAs) in BCC revealed that although these tumours were close to diploid and generally genetically stable, they did contain several recurrent aberrations. The loss of genetic material at 9q was identified in a third of BCC tumours studied. This is characteristic of inactivation of the PTCH tumour suppressor gene, a known attribute in some sporadic BCC development. Validation of this loss was performed via loss of heterozygosity, demonstrating good concordance with the CGH data. In addition the over-representation of the 6p chromosome arm was revealed in 47% of biopsies. This novel CNA is also commonly observed in other cutaneous neoplasias, including Merkel cell carcinoma and malignant melanoma. This suggests a possible common mechanism in development and or promotion in these cutaneous dysplasias, the mechanisms of which have yet to be clearly defined. In contrast to BCC, numerical genetic aberrations in SCC and SK were much more frequent. Several regions of recurrent gain were commonly shared between both dysplasias including gain of 3q, 4p, 5p, 8q, 9q, 14q, 17p, 17q and 20q. Common chromosomal regions of loss included 3p, 8p, 9p, 11p, 13q and 17p. In addition loss of chromosome 18 was significantly observed in SCC in comparison to SK, a possible defining event in SK progression to SCC. The identification of shared genetic aberrations suggests a clonal and genetic relationship between the two lesions. This information further supports the notion for re-classification of SK to an SCC in situ or superficial SCC. Finally, the CNAs detected have been similarly observed in other squamous cell-derived tumours, for example cervical and head and neck SCC. This provides further evidence to common mechanisms involved in the initiation, development and progression of SCC neoplasia. This study has identified a number of recurrent chromosomal regions, some of which are novel in NMSC development. The further delineation of these loci should provide additional evidence of their significance and degree of involvement in NMSC tumourigenesis. The identification of the cancer-causing genes mapped to these loci will further demarcate the genetic mechanisms of BCC and SCC progression. An understanding of the events involved in skin cancer formation and progression should shed additional light on molecular targets for diagnostics, management and therapeutic treatment.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2014-05-22T16:14:32Z No. of bitstreams: 1 Rozana Oliveira Gonçalves. Alterações... 2013.pdf: 539056 bytes, checksum: be74d5c934d4d2098ccee4e146563b3b (MD5) / Made available in DSpace on 2014-05-22T16:14:32Z (GMT). No. of bitstreams: 1 Rozana Oliveira Gonçalves. Alterações... 2013.pdf: 539056 bytes, checksum: be74d5c934d4d2098ccee4e146563b3b (MD5) Previous issue date: 2013 / Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / O abortamento é considerado um problema multifatorial, cujas principais causas envolvidas na sua etiologia são os fatores ambientais (como exposição a substâncias tóxicas), genéticos, anatômicos, endócrinos, imunológicos, trombofílicos e doenças infecciosas (como toxoplasmose, rubéola). No entanto, os fatores genéticos são atribuídos principalmente aos abortamentos de primeiro trimestre da gestação. As alterações cromossômicas, o polimorfismo C677T, no gene da metilenotetrahidrofolato redutase (MTHFR677C>T); o polimorfismo G1691A, no gene do Fator V de Leiden (FVL1691G>A), e o polimorfismo G20210A, no gene da protrombina (PRT20210G>A), têm sido associados a problemas obstétricos, incluindo aborto recorrente. O objetivo deste trabalho foi investigar associação entre as mutações relacionadas à trombofilia, presença de alterações cromossômicas e a ocorrência de aborto espontâneo recorrente e avaliar possíveis interações entre as referidas mutações e as alterações cromossômicas. A casuística foi composta por 151 mulheres com história de aborto recorrente, 94 parceiros e 100 controles (mulheres sem histórico de aborto). A investigação das mutações foi realizada pela técnica de Reação em Cadeia da Polimerase- Polimorfismo de Tamanho de Fragmento de Restrição. As alterações cromossômicas foram investigadas pela cariotipagem com banda–G. A frequência das alterações cromossômicas foi de 7,3% nas mulheres com abortamento recorrente e 1% nos controles (p=0,022), e de 2,1% nos parceiros. No entanto, a frequência dos alelos MTHR677C>T (23% versus 22,5%), FVL1691G>A (1,5% versus 1% ) e PRT20210G>A (1,45% versus 0%) foi similar entre casos e controles, respectivamente. No grupo investigado, foi observada associação entre aborto recorrente e alterações cromossômicas, mas não foi encontrada associação com os polimorfismos gênicos investigados. / Abortion is considered a multifactorial problem, the most important causes involved in its etiology are, environmental factors ( as exposure to toxic chemicals), genetic, anatomic, endocrine, immunological, thrombophilic and infectious diseases (such as toxoplasmosis, rubella). However, genetic factors are mainly attributed to abortions of the first trimester of pregnancy. Chromosomal abnormalities, MTHFR 677C>T, factor V Leiden 1691G>A and prothrombin 20210G>A mutations have been associated with obstetric problems, including recurrent miscarriage. The objective of this research was to investigate associations between mutations in three genes commonly associated to thrombophilic events, chromosomal abnormalities and the occurrence of recurrent miscarriage. As well evaluate possible interactions between these mutations and chromosomal abnormalities. The sample was comprised of 151 women with history of recurrent miscarriages, 94 partners and 100 control (women with no history of abortion). The investigation of the mutations was performed by Polymerase Chain Reaction (PCR)/ Restriction Fragment Length Polymorphism (RFLP). Chromosomal aberrations were investigated by karyotyping with G-banda. The frequency of chromosomal abnormalities was 7.3% in women with recurrent miscarriage and 1% in controls (p = 0.022), and 2.1% in the partners. However, the frequency of allele MTHR677C> T (23% versus 22.5%), FVL1691G> A (1.5% vs. 1%) and PRT20210G> A (1.45% vs. 0%) was similar for cases and controls, respectively. In the investigated group was found association between recurrent miscarriage and chromosomal abnormalities, but no association was found with the genetic polymorphisms investigated.

Résumé : Nous avons d’abord souhaité, dans ce travail de thèse, préciser les mécanismes moléculaires conduisant à l'expression ectopique du récepteur du GIP (glucose-dependent insulinotropic polypeptide receptor, GIPR) dans des adénomes somatotropes provenant de patients présentant une acromégalie avec une réponse paradoxale (stimulation) de l’hormone de croissance au glucose par voie orale. Nous avons montré que l’expression ectopique de GIPR se produit par une activation transcriptionnelle hypomorphe du gène GIPR associée à des anomalies de méthylation dans le corps du gène. L’activation de la voie AMP cyclique par le GIP postprandial dans les adénomes exprimant le GIPR peut représenter un mécanisme alternatif de la tumorigenèse somatotrope en l’absence de mutations de l’oncogène GNAS.Nous rapportons d’autre part une analyse cytogénétique approfondie des adénomes somatotropes, qui nous a permis de définir deux groupes d'adénomes, un groupe à faible altération du nombre de copies et un groupe à forte altération du nombre de copies. Deux tumeurs présentaient des réarrangements chromosomiques complexes avec une signature typique de chromothripsis, et une architecture sous-clonale incluant jusqu’à six populations cellulaires différentes, témoignant d’une hétérogénéité intratumorale importante.Dans une collection d'adénomes hypophysaires invasifs comportant la portion intrasellaire et la portion envahissante le sinus caverneux, nous avons montré par RNA-seq des profils d'expression génique divergents, apportant des arguments supplémentaires en faveur de l'hétérogénéité intratumorale dans ces tumeurs bénignes. Les échantillons tumoraux provenant de portions invasives ont montré une surexpression de la voie de transition épithélio-mésenchymateuse et des marqueurs de cellules souches cancéreuses soulignant leur rôle potentiel dans l’acquisition du phénotype invasif des cellules adénomateuses hypophysaires. / AbstractIn this work, we explored the molecular mechanisms of ectopic glucose-dependent insulinotropic polypeptide receptor (GIPR) expression in somatotroph adenomas from patients with acromegaly displaying a paradoxical GH increase to oral glucose. We showed that ectopic GIPR expression occurs through hypomorphic transcriptional activation of GIPR gene likely driven by DNA methylation changes. Activation of the cAMP pathway by postprandial GIP may represent an alternative tumorigenic mechanism in GIPR expressing somatotroph adenomas without driver mutations in GNAS oncogene. Cytogenetic profiling defined two groups of adenomas, a low-copy-number alteration (CNA) group and a high-CNA group.Two tumor samples displayed complex chromosomal rearrangements compatible with chromothripsis and showed subclonal architecture with up to six distinct cell population in each tumor, demonstrating an important intratumor heterogeneity.In a collection of invasive pituitary adenomas including the non-invasive intrasellar portions and the portions invading the cavernous sinuses, we showed by RNA-seq different gene expression profiles, providing supplemental evidence for the intratumoral heterogeneity in these benign tumors. Tumor samples from invasive portions showed up-regulation of the epithelial-mesenchymal transition pathway and increased expression of cancer stem-cell markers highlighting their potential role in pituitary tumor cell invasive behavior.

L’analyse des anomalies génomiques récurrentes est importante pour établir le diagnostic, le pronostic et pour orienter la thérapie des leucémies aiguës pédiatriques. L’objectif de notre étude est d’élaborer une stratégie optimale pour détecter les anomalies chromosomiques dans les leucémies aiguës lymphoblastiques (LAL) et myéloïdes (LAM) des enfants. Pour ce faire, nous avons caractérisé au caryotype, avec des panels d’hybridation in situ en fluorescence (FISH), par RT-PCR et par l’index d’ADN 253 leucémies de novo reçues au CHU Sainte-Justine entre 2005 et 2011 (186 LAL-B, 27 LAL-T et 40 LAM). Nous avons réussi à optimiser la détection des anomalies chromosomiques dans les trois types de leucémies, avec des fréquences de 93,5% dans les LAL-B (174/186), 66,7% dans les LAL-T (18/27) et 90% dans les LAM (36/40). Nos résultats suggèrent d’utiliser plusieurs tests génétiques concomitants afin d’optimiser la détection des anomalies génomiques dans les LAL et les LAM de novo pédiatriques. / Analysis of recurrent genomic abnormalities is important for the diagnosis, prognosis and therapeutic choices in paediatric acute leukemia. The aim of our study is to establish a strategy optimizing the detection of cytogenetic abnormalities in childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). To do so, we have characterized childhood AML and ALL cases received in cytogenetic laboratory of CHU Sainte-Justine (Montreal, Canada) between 2005 and 2011. Overall, 253 de novo cases have been analyzed (186 B-ALL, 27 T-ALL and 40 AML) by karyotyping, fluorescence in situ hybridization (FISH) panels, RT-PCR and DNA index. Chromosomal abnormalities detection rates achieved 93,5% in B-ALL (174/186), 66,7% in T-ALL (18/27) and 90% in AML (36/40). Our results suggest the analysis of both molecular and cytogenetic tests to optimize the detection of genomic abnormalities in new cases of childhood AML and ALL.

L’analyse des anomalies génomiques récurrentes est importante pour établir le diagnostic, le pronostic et pour orienter la thérapie des leucémies aiguës pédiatriques. L’objectif de notre étude est d’élaborer une stratégie optimale pour détecter les anomalies chromosomiques dans les leucémies aiguës lymphoblastiques (LAL) et myéloïdes (LAM) des enfants. Pour ce faire, nous avons caractérisé au caryotype, avec des panels d’hybridation in situ en fluorescence (FISH), par RT-PCR et par l’index d’ADN 253 leucémies de novo reçues au CHU Sainte-Justine entre 2005 et 2011 (186 LAL-B, 27 LAL-T et 40 LAM). Nous avons réussi à optimiser la détection des anomalies chromosomiques dans les trois types de leucémies, avec des fréquences de 93,5% dans les LAL-B (174/186), 66,7% dans les LAL-T (18/27) et 90% dans les LAM (36/40). Nos résultats suggèrent d’utiliser plusieurs tests génétiques concomitants afin d’optimiser la détection des anomalies génomiques dans les LAL et les LAM de novo pédiatriques. / Analysis of recurrent genomic abnormalities is important for the diagnosis, prognosis and therapeutic choices in paediatric acute leukemia. The aim of our study is to establish a strategy optimizing the detection of cytogenetic abnormalities in childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). To do so, we have characterized childhood AML and ALL cases received in cytogenetic laboratory of CHU Sainte-Justine (Montreal, Canada) between 2005 and 2011. Overall, 253 de novo cases have been analyzed (186 B-ALL, 27 T-ALL and 40 AML) by karyotyping, fluorescence in situ hybridization (FISH) panels, RT-PCR and DNA index. Chromosomal abnormalities detection rates achieved 93,5% in B-ALL (174/186), 66,7% in T-ALL (18/27) and 90% in AML (36/40). Our results suggest the analysis of both molecular and cytogenetic tests to optimize the detection of genomic abnormalities in new cases of childhood AML and ALL.

A Síndrome de Martin-Bell é uma forma hereditária de retardo mental determinada pela perda da expressão do gene FMR1 que está associado com a expansão da repetição dos tri-nucleotídeos citosina-guanina¬-guanina (CGG). Os indivíduos com um alto grau dessa expansão apresentam o silenciamento da expressão desse gene, com conseqüente alteração no desenvolvimento do sistema nervoso do embrião, causando danos neurológicos irreparáveis. A citogenética é uma metodologia clássica que contribui para o diagnóstico da síndrome em casos sem esclarecimentos, porém sua sensibilidade isoladamente em muitos casos é insuficiente para um diagnóstico positivo mesmo diante de características clínicas evidentes. Na busca de uma alternativa para suprir esta necessidade de definir exatamente as alterações encontradas em cada caso propôs-se a otimização de uma PCR de alta fidelidade no diagnóstico diferencial da Síndrome e simultaneamente comparar com os dados da citogenética clássica. Para tanto, foram coletadas amostras de sangue periférico de 102 pacientes e avaliou-se 100 a 150 metáfases para cada indivíduo pela citogenética clássica e para a PCR duplex. Os resultados demonstram pelo teste de Kruskal-Wallis que a PCR com a citogenética não apresentou diferenças significativas (p>0,05). Porém quando avaliadados pelo índice de Kappa sugere-se que os dois critéiros de diagnósticos devem ser utilizados simultaneamente com caracteristicas clínicas do paciente. A PCR mostrou-se rápida e com custo relativamente menor, sendo portanto, aplicável no auxílio ao aconselhamento genético dos indivíduos e suas famílias, bem como para um acompanhamento psico-pedagógico adequado. / The Martin-Bell Syndrome is a heredity mental retard form determined by the loss of FMR1 gene expression which is associated with the tri-nucleotides cytosine-guanine-guanine (CGG) repetition expansion. The individuals showing a high degree of this expansion present the silencing of this gene expression, with a consequent alteration of the embryo nervous system evolution, causing irreparable neurological damage The cytogenetics is a classical methodology that contributes for diagnosing the syndrome in cases without clarification, thus its sensitivity isolated in many cases is insufficient for a positive diagnosis even in front of evident clinical characteristics. On searching for an alternative to fulfill this need to define the found alterations in each case, an optimization of a high fidelity PCR to Syndrome diagnosis and simultaneously to compare with classical cytogenetics. Peripheral blood samples were collected from 102 patients for evaluating 100 to 150 metaphases evaluation by classical cytogenetics for each sample and to duplex PCR. The results showed by the Kruskal-Wallis test that the PCR with the cytogenetics have not presented significant differences (p>0,05). However, when evaluated by the Kappa index it was suggested that the two diagnosis criteria should be used simultaneously with patient s clinical characteristics. The PCR showed itself quick and with a relatively lower cost , and in this way, applicable in helping genetically counseling individuals and their families, as well as sending them to a more adequate psycho-pedagogical treatment.

Objetivo: analisar o resultado das gestações e pós-natal dos fetos com translucência nucal (TN) aumentada. Método: Duzentos e setenta e cinco fetos com TN aumentada foram avaliados no setor de Medicina Fetal da Clínica Obstétrica do HC-FMUSP, com análise do cariótipo, ultra-sonografia seriada, ecocardiografias fetal e pós-natal e avaliação clinica genética pós-natal. Resultados: 14,2% apresentaram cariótipos alterados e 85,8% normais. A ultra-sonografia morfológica esteve alterada em 73,1% dos casos com cariótipo anormal e em 24,7% dos normais, destes, um terço apresentou malformações estruturais maiores, sendo 35,7% cardíacas. Resultados gestacionais adversos, como abortamento, óbitos intra-útero e neonatal ocorreram em 76,5% dos fetos com anomalias cromossômicas e em 10,2% com cariótipos normais. A avaliação pós-natal foi realizada em 72,7% das crianças, mostrando-se alterada em 14,8% dos casos. A freqüência de criança viva e saudável diminuiu com a medida da TN, que variou de 37,5%, nos casos com cariótipos normais, a 18,8% com cariótipos desconhecidos, quando a TN foi igual ou maior que 4,5 mm. Conclusão: Quanto maior a TN maior o risco de anomalias cromossômicas e, nos casos com cariótipos normais, maior a freqüência de malformações estruturais, em especial defeitos cardíacos, resultados gestacionais adversos e alterações à avaliação pós-natal / The aim of this study was to evaluate pregnancy and postnatal outcomes in fetuses with increased nuchal translucency thickness (NT). Two hundred seventy five fetuses with increased NT were examined with karyotyping analysys, serial ultrasound scans, ecocardiography and postnatal clinical and genetic evaluation at the Fetal Medicine Unit - Departament of Obstetrics - São Paulo University. The karyotype was abnormal in 14.2% of the cases and normal in 85.8%. At the anomaly scan, 73.1% of the abnormal karyotype and 24.7% of the normal fetuses presented structural abnormalities, one third of these were major malformations with 35.7% of cardiac defects. Adverse pregnancy outcome as miscarriages, intrauterine and neonatal deaths occurred in 76.5% of the abnormal karyotype group and in 10.2% of the normal. 72.7% of the infants with normal karyotype had postnatal examination with 14,8% presenting abnormalities. The chances of having a live and healthy child decreased with increased NT thickness. For NT above 4.5mm this varied from 18.8%, for an unknown karyotype result, to 37.5% for a normal karyotype. The chances of abnormal karyotype increased with NT thickness. In addition, when the karyotype was normal, the frequency of fetal malformations, specially heart defects, adverse pregnancy outcome and postnatal abnormalities increased with NT thickness

Objetivo: analisar o resultado das gestações e pós-natal dos fetos com translucência nucal (TN) aumentada. Método: Duzentos e setenta e cinco fetos com TN aumentada foram avaliados no setor de Medicina Fetal da Clínica Obstétrica do HC-FMUSP, com análise do cariótipo, ultra-sonografia seriada, ecocardiografias fetal e pós-natal e avaliação clinica genética pós-natal. Resultados: 14,2% apresentaram cariótipos alterados e 85,8% normais. A ultra-sonografia morfológica esteve alterada em 73,1% dos casos com cariótipo anormal e em 24,7% dos normais, destes, um terço apresentou malformações estruturais maiores, sendo 35,7% cardíacas. Resultados gestacionais adversos, como abortamento, óbitos intra-útero e neonatal ocorreram em 76,5% dos fetos com anomalias cromossômicas e em 10,2% com cariótipos normais. A avaliação pós-natal foi realizada em 72,7% das crianças, mostrando-se alterada em 14,8% dos casos. A freqüência de criança viva e saudável diminuiu com a medida da TN, que variou de 37,5%, nos casos com cariótipos normais, a 18,8% com cariótipos desconhecidos, quando a TN foi igual ou maior que 4,5 mm. Conclusão: Quanto maior a TN maior o risco de anomalias cromossômicas e, nos casos com cariótipos normais, maior a freqüência de malformações estruturais, em especial defeitos cardíacos, resultados gestacionais adversos e alterações à avaliação pós-natal / The aim of this study was to evaluate pregnancy and postnatal outcomes in fetuses with increased nuchal translucency thickness (NT). Two hundred seventy five fetuses with increased NT were examined with karyotyping analysys, serial ultrasound scans, ecocardiography and postnatal clinical and genetic evaluation at the Fetal Medicine Unit - Departament of Obstetrics - São Paulo University. The karyotype was abnormal in 14.2% of the cases and normal in 85.8%. At the anomaly scan, 73.1% of the abnormal karyotype and 24.7% of the normal fetuses presented structural abnormalities, one third of these were major malformations with 35.7% of cardiac defects. Adverse pregnancy outcome as miscarriages, intrauterine and neonatal deaths occurred in 76.5% of the abnormal karyotype group and in 10.2% of the normal. 72.7% of the infants with normal karyotype had postnatal examination with 14,8% presenting abnormalities. The chances of having a live and healthy child decreased with increased NT thickness. For NT above 4.5mm this varied from 18.8%, for an unknown karyotype result, to 37.5% for a normal karyotype. The chances of abnormal karyotype increased with NT thickness. In addition, when the karyotype was normal, the frequency of fetal malformations, specially heart defects, adverse pregnancy outcome and postnatal abnormalities increased with NT thickness

A Síndrome de Martin-Bell é uma forma hereditária de retardo mental determinada pela perda da expressão do gene FMR1 que está associado com a expansão da repetição dos tri-nucleotídeos citosina-guanina¬-guanina (CGG). Os indivíduos com um alto grau dessa expansão apresentam o silenciamento da expressão desse gene, com conseqüente alteração no desenvolvimento do sistema nervoso do embrião, causando danos neurológicos irreparáveis. A citogenética é uma metodologia clássica que contribui para o diagnóstico da síndrome em casos sem esclarecimentos, porém sua sensibilidade isoladamente em muitos casos é insuficiente para um diagnóstico positivo mesmo diante de características clínicas evidentes. Na busca de uma alternativa para suprir esta necessidade de definir exatamente as alterações encontradas em cada caso propôs-se a otimização de uma PCR de alta fidelidade no diagnóstico diferencial da Síndrome e simultaneamente comparar com os dados da citogenética clássica. Para tanto, foram coletadas amostras de sangue periférico de 102 pacientes e avaliou-se 100 a 150 metáfases para cada indivíduo pela citogenética clássica e para a PCR duplex. Os resultados demonstram pelo teste de Kruskal-Wallis que a PCR com a citogenética não apresentou diferenças significativas (p>0,05). Porém quando avaliadados pelo índice de Kappa sugere-se que os dois critéiros de diagnósticos devem ser utilizados simultaneamente com caracteristicas clínicas do paciente. A PCR mostrou-se rápida e com custo relativamente menor, sendo portanto, aplicável no auxílio ao aconselhamento genético dos indivíduos e suas famílias, bem como para um acompanhamento psico-pedagógico adequado. / The Martin-Bell Syndrome is a heredity mental retard form determined by the loss of FMR1 gene expression which is associated with the tri-nucleotides cytosine-guanine-guanine (CGG) repetition expansion. The individuals showing a high degree of this expansion present the silencing of this gene expression, with a consequent alteration of the embryo nervous system evolution, causing irreparable neurological damage The cytogenetics is a classical methodology that contributes for diagnosing the syndrome in cases without clarification, thus its sensitivity isolated in many cases is insufficient for a positive diagnosis even in front of evident clinical characteristics. On searching for an alternative to fulfill this need to define the found alterations in each case, an optimization of a high fidelity PCR to Syndrome diagnosis and simultaneously to compare with classical cytogenetics. Peripheral blood samples were collected from 102 patients for evaluating 100 to 150 metaphases evaluation by classical cytogenetics for each sample and to duplex PCR. The results showed by the Kruskal-Wallis test that the PCR with the cytogenetics have not presented significant differences (p>0,05). However, when evaluated by the Kappa index it was suggested that the two diagnosis criteria should be used simultaneously with patient s clinical characteristics. The PCR showed itself quick and with a relatively lower cost , and in this way, applicable in helping genetically counseling individuals and their families, as well as sending them to a more adequate psycho-pedagogical treatment.

Cosupervision / Le test génomique prénatal non invasif (TGPNI) est un test de dépistage prénatal offert pour détecter certaines anomalies chromosomiques chez le fœtus, telles que les trisomies 21, 18 et 13. Au Canada, la disponibilité et l’offre du TGPNI varient d’une province et d'un territoire à l'autre mais sont surtout en deuxième intention. Cette étude qualitative a consisté en des entretiens approfondis avec onze personnes vivant avec ou côtoyant une condition génétique actuellement ou potentiellement détectée par le TGPNI, pour explorer leurs perspectives quant à la proposition d’implanter ce test en 1re intention, et d’en étendre la portée vers la détection d’autres conditions génétiques. L’analyse a révélé que, bien que certains individus apprécient un résultat précoce grâce au TGPNI, ils considèrent généralement le dépistage prénatal comme une voie prédéterminée vers l’interruption de grossesse. Cette corrélation était liée à leur expérience personnelle du dépistage et à celle de leur communauté, où de nombreuses pressions sont subies en cas d’anomalie fœtale. Les parents estiment que l'attente sociale envers l'interruption de grossesse reflète les attitudes négatives de la société à l'égard des personnes génétiquement différentes, craignant que l’offre étendue et plus accessible du TGPNI n’accentue la pente glissante vers des tendances eugéniques dans la société. L’expansion de la portée du test pourrait être bénéfique dans le cas de conditions génétiques jugées sévères sur la base des critères de viabilité et de qualité de vie. Cependant, les personnes côtoyant des anomalies des chromosomes sexuels (ACS) ont également soutenu l'utilisation du TGPNI pour la détection des ACS, afin de permettre une meilleure préparation prénatale, ce à quoi les parents d'enfants vivant avec la trisomie 21 étaient plus réticents. Les parents ont rétrospectivement contrasté ces attitudes avec la réalité d’élever un enfant vivant avec une condition génétique, qu'ils décrivent comme une expérience pleine de défis mais hautement enrichissante. Bien que les participant.e.s apprécient le TGPNI en tant qu’outil d'information favorisant l’autonomie reproductive, ils et elles estiment qu'il devrait être accompagné d'informations équilibrées, transparentes et exemptes de biais. Ces résultats réitèrent l’importance de consulter les personnes vivant au cœur de ces enjeux, afin d’ajouter leurs perspectives aux voix des autres parties prenantes dans la prise de décision en matière de santé, en maintenant l'autonomie reproductive et la protection des droits des personnes vulnérables sont placées à l’avant-plan des considérations. / Non-invasive prenatal genomic testing (NIPT) is a prenatal screening test offered to detect certain chromosomal abnormalities in the fetus, such as trisomies 21, 18 and 13. In Canada, the availability and offr of NIPT varies among the provinces and territories but is mainly second-tier. This qualitative study involved in-depth interviews with eleven people living with a genetic condition currently or potentially detected by NIPT, to explore their opinion regarding its potential implementation as first- tier testing, and to extend its scope to the detection of other genetic conditions. The analysis revealed that, although some individuals appreciated an early result with NIPT, they generally considered prenatal screening as a predetermined route to termination of pregnancy. This correlation was linked to their personal experience of screening and that of their community, where there is a great amount of pressure in the case of a fetal anomaly. Parents felt that the social expectation to terminate a pregnancy reflected society’s negative attitudes towards people who are genetically different, fearing that the expanded and more accessible offer of NIPT would accentuate the slippery slope towards eugenic tendencies in society. Thus, the expansion of the test’s scope could be beneficial only in the case of genetic conditions deemed severe on the basis of viability and quality-of-life criteria. However, people living with sex chromosome anomalies (SCAs) also supported the use of NIPT for the detection of SCAs, to enable better prenatal preparation, something to which parents of children living with trisomy 21 were more reluctant. In retrospect, parents contrasted these attitudes with the reality of raising a child living with a genetic condition, which they described as a challenging but highly rewarding experience. While participants appreciated the TGPNI as an information tool promoting reproductive autonomy, they felt that it should be accompanied by balanced, transparent and bias-free information. These results reiterate the importance of consulting people living at the heart of these issues, in order to add their perspectives to the voices of other stakeholders in healthcare decision-making, keeping reproductive autonomy and the protection of vulnerable people’s rights at the forefront of considerations.