Clinical and Molecular Characterization of Adult Glioblastomas in Southern Brazil.

We investigated 113 adult Brazilian patients with glioblastoma (GBM) for comparison with patients from distinct geographical areas and evaluation of suitability for novel targeted therapies. Patients were assessed for clinical features and tumor genomic characteristics such as ROS1 and NTRK1 rearrangements, KIT, PDGFRA, and KDR amplification, and RB1 deletion using multicolor fluorescence in situ hybridization. The majority of patients were male (53%), over 40 years (94%), with tumor located in single site (64%), in the right cerebral hemisphere (60%), and underwent partial resection (71%); 14% presented complications after surgery. The main clinical sign at diagnosis was focal abnormality (57%); frontal (31%); and temporal (20%) regions were most commonly affected. Median hospitalization time was 20 days, median survival was 175 days. One tumor was positive for rearrangement in NTRK1 and another in ROS1 (0.9% each). PDGFRA was amplified in 20% of cases, often co-amplified with KDR (>90%) and KIT (>60%). RB1 was deleted in 16% of patients. There was no association between these molecular abnormalities and patient survival. However, older age, complications after surgery, and right-sided tumors were independent variables associated with patient survival. This study contributes information on the molecular profile of glioblastomas in Latin America possibly supporting new target therapies.

Regulatory variants of FOXG1 in the context of its topological domain organisation.

FOXG1 syndrome is caused by FOXG1 intragenic point mutations, or by long-range position effects (LRPE) of intergenic structural variants. However, the size of the FOXG1 regulatory landscape is uncertain, because the associated topologically associating domain (TAD) in fibroblasts is split into two domains in embryonic stem cells (hESC). Indeed, it has been suggested that the pathogenetic mechanism of deletions that remove the stem-cell-specific TAD boundary may be enhancer adoption due to ectopic activity of enhancer(s) located in the distal hESC-TAD. Herein we map three de novo translocation breakpoints to the proximal regulatory domain of FOXG1. The classical FOXG1 syndrome in these and in other translocation patients, and in a patient with an intergenic deletion that removes the hESC-specific TAD boundary, do not support the hypothesised enhancer adoption as a main contributor to the FOXG1 syndrome. Also, virtual 4 C and HiC-interaction data suggest that the hESC-specific TAD boundary may not be critical for FOXG1 regulation in a majority of human cells and tissues, including brain tissues and a neuronal progenitor cell line. Our data support the importance of a critical regulatory region (SRO) proximal to the hESC-specific TAD boundary. We further narrow this critical region by a deletion distal to the hESC-specific boundary, associated with a milder clinical phenotype. The distance from FOXG1 to the SRO ( > 500 kb) highlight a limitation of ENCODE DNase hypersensitivity data for functional prediction of LRPE. Moreover, the SRO has little overlap with a cluster of frequently associating regions (FIREs) located in the proximal hESC-TAD.

Two cases of polydactyly in wild brown howler monkeys (Alouatta guariba clamitans).

We report the first two cases of polydactyly in an atelid species: (i) a wild ca. 16-week-old infant female presenting seven digits in both feet and other bone malformations and (ii) a wild newborn male presenting six digits in both feet with the extra digit fused to the hallux.

Clinical utility of skin karyotype / Utilidade clínica do cariótipo de pele

ABSTRACTWe report the case of a patient with Patau syndrome, diagnosed by skin karyotype, emphasizing the applications and importance of this test. The pregnancy morphology ultrasound showed face defects and of central nervous system and heart chambers asymmetry. In the postnatal evaluation it was identified microcephaly, single central nostril, and other malformations. We performed skin karyotype that resulted in full trisomy 13. Our report highlights the possibility of performing karyotype examination in cases when it is no longer possible to obtain a blood sample, thus providing the correct diagnosis and genetic counseling for the family.

RESUMORelatamos o caso de uma paciente com síndrome de Patau, diagnosticada por meio do cariótipo de pele, salientando as aplicações e a importância deste exame. Na ultrassonografia morfológica da gravidez, apresentou malformações de face, sistema nervoso central e assimetria de câmaras cardíacas. No pós-natal, identificou-se microcefalia e narina única central, além de outras malformações. Realizamos cariótipo de pele que resultou em trissomia livre do cromossomo 13. Nosso relato destaca a possibilidade da realização deste exame em casos nos quais não é mais possível a obtenção de amostra de sangue, proporcionando assim o correto diagnóstico e aconselhamento genético para a família.

Clinical and cytogenetic features of a Brazilian sample of patients with phenotype of oculo-auriculo-vertebral spectrum: a cross-sectional study / Características clínicas e citogenéticas de uma amostra brasileira de pacientes com fenótipo de espectro óculo-aurículo-vertebral: um estudo transversal

CONTEXT AND OBJECTIVE: Oculo-auriculo-vertebral spectrum (OAVS) is considered to be a defect of embryogenesis involving structures originating from the first branchial arches. Our objective was to describe the clinical and cytogenetic findings from a sample of patients with the phenotype of OAVS. DESIGN AND SETTING: Cross-sectional study in a referral hospital in southern Brazil. METHODS: The sample consisted of 23 patients who presented clinical findings in at least two of these four areas: orocraniofacial, ocular, auricular and vertebral. The patients underwent a clinical protocol and cytogenetic evaluation through high-resolution karyotyping, fluorescence in situ hybridization for 5p and 22q11 microdeletions and investigation of chromosomal instability for Fanconi anemia. RESULTS: Cytogenetic abnormalities were observed in three cases (13%) and consisted of: 47,XX,+mar; mos 47,XX,+mar/46,XX; and 46,XX,t(6;10)(q13; q24). We observed cases of OAVS with histories of gestational exposition to fluoxetine, retinoic acid and crack. One of our patients was a discordant monozygotic twin who had shown asymmetrical growth restriction during pregnancy. Our patients with OAVS were characterized by a broad clinical spectrum and some presented atypical findings such as lower-limb reduction defect and a tumor in the right arm, suggestive of hemangioma/lymphangioma. CONCLUSIONS: We found a wide range of clinical characteristics among the patients with OAVS. Different chromosomal abnormalities and gestational expositions were also observed. Thus, our findings highlight the heterogeneity of the etiology of OAVS and the importance of these factors in the clinical and cytogenetic evaluation of these patients. .

CONTEXTO E OBJETIVO: O espectro oculoauriculovertebral (EOAV) é considerado um defeito de embriogênese envolvendo estruturas originadas a partir dos primeiros arcos branquiais. Nosso objetivo foi descrever os achados clínicos e citogenéticos de uma amostra de pacientes com fenótipo de EOAV. TIPO DE ESTUDO E LOCAL: Estudo transversal em um hospital de referência no sul do Brasil. MÉTODOS: A amostra foi composta de 23 pacientes que apresentaram achados clínicos em pelo menos duas das quatro áreas: orocraniofacial, oculares, auriculares e vertebrais. Os pacientes foram submetidos a um protocolo clínico e avaliação citogenética através do cariótipo de alta resolução, hibridização in situ fluorescente para as microdeleções 5p e 22q11 e pesquisa de instabilidade cromossômica para anemia de Fanconi. RESULTADOS: Alterações citogenéticas foram observadas em três casos (13%) e consistiam de: 47,XX,+mar; mos 47,XX,+mar/46,XX e 46,XX,t(6;10)(q13;q24). Observamos casos de EOAV com história de exposição gestacional à fluoxetina, ácido retinoico e crack. Um dos nossos pacientes foi um gêmeo monozigótico discordante que teve restrição de crescimento assimétrica durante a gravidez. Nossos pacientes com EOAV foram caracterizados por um amplo espectro clínico e alguns apresentaram achados clínicos atípicos como um defeito de redução de membro inferior e um tumor do braço direito, sugestivo de hemangioma/linfangioma. CONCLUSÕES: Verificamos grande variedade de características clínicas entre os pacientes com EOAV. Também foram observadas diferentes anomalias cromossômicas e exposições gestacionais. Assim, nossos achados salientam a heterogeneidade da etiologia do EOAV e a importância desses fatores na avaliação clínica e citogenética desses pacientes. .

Clinical and cytogenetic features of a Brazilian sample of patients with phenotype of oculo-auriculo-vertebral spectrum: a cross-sectional study.

CONTEXT AND OBJECTIVE: Oculo-auriculo-vertebral spectrum (OAVS) is considered to be a defect of embryogenesis involving structures originating from the first branchial arches. Our objective was to describe the clinical and cytogenetic findings from a sample of patients with the phenotype of OAVS. DESIGN AND SETTING: Cross-sectional study in a referral hospital in southern Brazil. METHODS: The sample consisted of 23 patients who presented clinical findings in at least two of these four areas: orocraniofacial, ocular, auricular and vertebral. The patients underwent a clinical protocol and cytogenetic evaluation through high-resolution karyotyping, fluorescence in situ hybridization for 5p and 22q11 microdeletions and investigation of chromosomal instability for Fanconi anemia. RESULTS: Cytogenetic abnormalities were observed in three cases (13%) and consisted of: 47,XX,+mar; mos 47,XX,+mar/46,XX; and 46,XX,t(6;10)(q13; q24). We observed cases of OAVS with histories of gestational exposition to fluoxetine, retinoic acid and crack. One of our patients was a discordant monozygotic twin who had shown asymmetrical growth restriction during pregnancy. Our patients with OAVS were characterized by a broad clinical spectrum and some presented atypical findings such as lower-limb reduction defect and a tumor in the right arm, suggestive of hemangioma/lymphangioma. CONCLUSIONS: We found a wide range of clinical characteristics among the patients with OAVS. Different chromosomal abnormalities and gestational expositions were also observed. Thus, our findings highlight the heterogeneity of the etiology of OAVS and the importance of these factors in the clinical and cytogenetic evaluation of these patients.

45,X/46,XY mosaicism: report on 14 patients from a Brazilian hospital. A retrospective study / Mosaicismo 45,X/46,XY: relato de 14 pacientes de um hospital do Brasil. Um estudo retrospectivo

CONTEXT AND OBJECTIVE: 45,X/46,XY mosaicism, or mixed gonadal dysgenesis, is considered to be a rare disorder of sex development. The aim of our study was to investigate the clinical and cytogenetic characteristics of patients with this mosaicism. DESIGN AND SETTING: A retrospective study in a referral hospital in southern Brazil. METHODS: Our sample consisted of patients diagnosed at the clinical genetics service of a referral hospital in southern Brazil, from 1975 to 2012. Clinical and cytogenetic data were collected from the medical records. RESULTS: Fourteen patients were included in the sample, with ages at the first evaluation ranging from 2 days to 38 years. Nine of them had female sex of rearing and five, male. Regarding the external genitalia, most were ambiguous (n = 10). One patient presented male phenotype and was treated for a history of azoospermia, while three patients presented female phenotype, of whom two had findings of Turner syndrome and one presented secondary amenorrhea alone. Some findings of Turner syndrome were observed even among patients with ambiguous genitalia. None presented gonadal malignancy. One patient underwent surgical correction for genital ambiguity and subsequent exchange of sex of rearing. Regarding cytogenetics, we did not observe any direct correlation between percentages of cell lines and phenotype. CONCLUSIONS: 45,X/46,XY mosaicism can present with a wide variety of phenotypes resulting from the involvement of different aspects of the individual. All these observations have important implications for early recognition of these patients and their appropriate management. .

CONTEXTO E OBJETIVO: O mosaicismo 45,X/46,XY, ou disgenesia gonadal mista, é considerado uma doença rara do desenvolvimento sexual. O objetivo do nosso estudo foi verificar as características clínicas e citogenéticas de pacientes com este mosaicismo. TIPO DE ESTUDO E LOCAL: Estudo retrospectivo em um hospital de referência no sul do Brasil. MÉTODOS: Nossa amostra foi composta por pacientes diagnosticados em um serviço de genética clínica de um hospital de referência no sul do Brasil, no período de 1975 até 2012. Os dados clínicos e citogenéticos foram coletados a partir dos prontuários médicos. RESULTADOS: Catorze pacientes foram incluídos na amostra, idades na primeira avaliação variando de 2 dias a 38 anos. Nove deles apresentavam sexo feminino de criação e cinco, masculino. A genitália externa, na maioria, era ambígua (n = 10). O paciente com fenótipo masculino foi tratado por história de azoospermia, enquanto que das três pacientes do fenótipo feminino, duas apresentavam achados da síndrome de Turner e a outra, amenorreia secundária isolada. Alguns achados da síndrome de Turner foram observados mesmo entre pacientes com genitália ambígua. Nenhum deles apresentou neoplasia gonadal. Um paciente foi submetido à correção cirúrgica de ambiguidade genital e posterior troca de sexo de criação. Quanto à citogenética, não observamos correlação direta entre a porcentagem de linhas de células e o fenótipo. CONCLUSÕES: O mosaicismo 45,X/46,XY pode apresentar grande variedade de fenótipos resultantes do envolvimento de diferentes aspectos do indivíduo. Todas essas observações têm implicações importantes para o reconhecimento precoce desses pacientes e seu adequado manejo. .

45,X/46,XY mosaicism: report on 14 patients from a Brazilian hospital. A retrospective study.

CONTEXT AND OBJECTIVE: 45,X/46,XY mosaicism, or mixed gonadal dysgenesis, is considered to be a rare disorder of sex development. The aim of our study was to investigate the clinical and cytogenetic characteristics of patients with this mosaicism. DESIGN AND SETTING: A retrospective study in a referral hospital in southern Brazil. METHODS: Our sample consisted of patients diagnosed at the clinical genetics service of a referral hospital in southern Brazil, from 1975 to 2012. Clinical and cytogenetic data were collected from the medical records. RESULTS: Fourteen patients were included in the sample, with ages at the first evaluation ranging from 2 days to 38 years. Nine of them had female sex of rearing and five, male. Regarding the external genitalia, most were ambiguous (n = 10). One patient presented male phenotype and was treated for a history of azoospermia, while three patients presented female phenotype, of whom two had findings of Turner syndrome and one presented secondary amenorrhea alone. Some findings of Turner syndrome were observed even among patients with ambiguous genitalia. None presented gonadal malignancy. One patient underwent surgical correction for genital ambiguity and subsequent exchange of sex of rearing. Regarding cytogenetics, we did not observe any direct correlation between percentages of cell lines and phenotype. CONCLUSIONS: 45,X/46,XY mosaicism can present with a wide variety of phenotypes resulting from the involvement of different aspects of the individual. All these observations have important implications for early recognition of these patients and their appropriate management.

Congenital heart disease and chromossomopathies detected by the karyotype.

OBJECTIVE: To review the relationship between congenital heart defects and chromosomal abnormalities detected by the karyotype. DATA SOURCES: Scientific articles were searched in MEDLINE database, using the descriptors "karyotype" OR "chromosomal" OR "chromosome" AND "heart defects, congenital". The research was limited to articles published in English from 1980 on. DATA SYNTHESIS: Congenital heart disease is characterized by an etiologically heterogeneous and not well understood group of lesions. Several researchers have evaluated the presence of chromosomal abnormalities detected by the karyotype in patients with congenital heart disease. However, most of the articles were retrospective studies developed in Europe and only some of the studied patients had a karyotype exam. In this review, only one study was conducted in Latin America, in Brazil. It is known that chromosomal abnormalities are frequent, being present in about one in every ten patients with congenital heart disease. Among the karyotype alterations in these patients, the most important is the trisomy 21 (Down syndrome). These patients often have associated extra-cardiac malformations, with a higher risk of morbidity and mortality, which makes heart surgery even more risky. CONCLUSIONS: Despite all the progress made in recent decades in the field of cytogenetic, the karyotype remains an essential tool in order to evaluate patients with congenital heart disease. The detailed dysmorphological physical examination is of great importance to indicate the need of a karyotype.

Congenital heart disease and chromossomopathies detected by the karyotype / Cardiopatías congénitas y anomalías cromosómicas detectadas mediante cariotipo / Cardiopatias congênitas e cromossomopatias detectadas por meio do cariótipo

To review the relationship between congenital heart defects and chromosomal abnormalities detected by the karyotype. DATA SOURCES: Scientific articles were searched in MEDLINE database, using the descriptors "karyotype" OR "chromosomal" OR "chromosome" AND "heart defects, congenital". The research was limited to articles published in English from 1980 on. DATA SYNTHESIS: Congenital heart disease is characterized by an etiologically heterogeneous and not well understood group of lesions. Several researchers have evaluated the presence of chromosomal abnormalities detected by the karyotype in patients with congenital heart disease. However, most of the articles were retrospective studies developed in Europe and only some of the studied patients had a karyotype exam. In this review, only one study was conducted in Latin America, in Brazil. It is known that chromosomal abnormalities are frequent, being present in about one in every ten patients with congenital heart disease. Among the karyotype alterations in these patients, the most important is the trisomy 21 (Down syndrome). These patients often have associated extra-cardiac malformations, with a higher risk of morbidity and mortality, which makes heart surgery even more risky. CONCLUSIONS: Despite all the progress made in recent decades in the field of cytogenetic, the karyotype remains an essential tool in order to evaluate patients with congenital heart disease. The detailed dysmorphological physical examination is of great importance to indicate the need of a karyotype...

Realizar una revisión de la literatura sobre la relación de las cardiopatías congénitas con anormalidades cromosómicas detectadas por medio del examen de cariotipo. FUENTES DE DATOS: Se investigaron artículos científicos en el portal MEDLINE, utilizándose los descriptores "karyotype", OR "chromosomal" OR "chromosome" AND "heart defects, congenital". La investigación se limitó a artículos publicados en inglés a partir de la década de los 1980. SÍNTESIS DE LOS DATOS: Las cardiopatías congénitas son un grupo de lesiones etiológicamente heterogéneo y poco comprendido. Varios investigadores evaluaron la presencia de anormalidades cromosómicas detectadas por el examen de cariotipo en pacientes portadores de cardiopatía congénita. Sin embargo, la mayoría de los artículos estaba compuesta por trabajos retrospectivos desarrollados en Europa, en los que no todos los pacientes fueron sometidos a la evaluación cariotípica. En esta revisión, se encontró solamente un estudio desarrollado en Latinoamérica, en Brasil. Se sabe que anormalidades cromosómicas son frecuentes, estando presentes en aproximadamente uno a cada diez pacientes con cardiopatía congénita. Entre las alteraciones observadas, se destaca la trisomía del cromosoma 21 (síndrome de Down). Esos pacientes frecuentemente presentan malformaciones extracardíacas asociadas y riesgo más grande de morbidez y mortalidad, lo que hace la cirugía cardíaca todavía más arriesgada. CONCLUSIONES: A pesar de todos avances ocurridos las últimas décadas en el área de la citogenética, el examen de cariotipo sigue siendo una herramienta fundamental para evaluar pacientes con cardiopatía congénita. El examen físico dismorfológico minucioso, realizado...

Realizar uma revisão da literatura sobre a relação das cardiopatias congênitas com anormalidades cromossômicas detectadas por meio do exame de cariótipo. FONTES DE DADOS: Pesquisaram-se artigos científicos no portal MEDLINE, utilizando-se os descritores "karyotype" OR "chromosomal" OR "chromosome" AND "heart defects, congenital". A pesquisa limitou-se a artigos publicados em inglês a partir da década de 1980. SÍNTESE DOS DADOS: As cardiopatias congênitas são um grupo de lesões etiologicamente heterogêneo e pouco compreendido. Vários pesquisadores avaliaram a presença de anormalidades cromossômicas detectadas pelo exame de cariótipo em pacientes portadores de cardiopatia congênita. Porém, a maioria dos artigos era composta de trabalhos retrospectivos desenvolvidos na Europa, nos quais nem todos os pacientes foram submetidos à avaliação cariotípica. Nesta revisão, encontrou-se apenas um estudo desenvolvido na América Latina, no Brasil. Sabe-se que anormalidades cromossômicas são frequentes, estando presentes em cerca de um em cada dez pacientes com cardiopatia congênita. Dentre as alterações observadas, destaca-se a trissomia do cromossomo 21 (síndrome de Down). Esses pacientes frequentemente apresentam malformações extracardíacas associadas e risco maior de morbidade e mortalidade, tornando a cirurgia cardíaca ainda mais arriscada. CONCLUSÕES: Apesar de todos os avanços ocorridos nas últimas décadas na área da citogenética, o exame de cariótipo continua sendo uma ferramenta fundamental para se avaliarem pacientes com cardiopatia congênita. O exame físico dismorfológico minucioso é de grande importância para indicar a realização do cariótipo...

Gómez-López-Hernández syndrome in a child born to consanguineous parents: new evidence for an autosomal-recessive pattern of inheritance?

BACKGROUND: Gómez-López-Hernández syndrome is a rare genetic disease characterized by scalp alopecia with trigeminal anesthesia, brachycephaly or turribrachycephaly, midface retrusion, and rhombencephalosynapsis. We report the second case with this condition who presented with consanguineous parents. PATIENT: This boy was evaluated shortly after birth because of suspected craniosynostosis. He was the only son of healthy, consanguineous parents (his maternal grandmother and his paternal great-grandfather were siblings). His examination was notable for turribrachycephaly, prominent forehead, bilateral parietotemporal alopecia, midfacial retrusion, anteverted nostrils, micrognathia, low-set and posteriorly rotated ears, and short neck with redundant skin. Radiographs and tridimensional computed tomography scan of skull revealed lambdoid craniosynostosis. Brain magnetic resonance imaging revealed complete rhombencephalosynapsis, aqueductal stenosis, fused colliculi, abnormal superior cerebellar penducle, mild ventriculomegaly, and dysgenesis of the corpus callosum. CONCLUSIONS: Since its first description, 34 patients with this condition have been reported. The etiology of Gómez-López-Hernández syndrome is unknown. However, it is noteworthy that the patient in this report presented with a family history of consanguinity because this finding reinforces the possibility of an autosomal-recessive inheritance for this condition.

Tri-allelic pattern at the TPOX locus: a familial study.

Alleles at the TPOX STR locus have 6-14 different numbers of a four-nucleotide (AATG) repeat motif arranged in tandem. Although tri-allelic genotypes are generally rare, the TPOX tri-allelic pattern has a higher frequency, varying widely among populations. Despite this, there are few accurate reports to disclose the nature of the TPOX third allele. In this work we present data obtained from 45 individuals belonging to the same pedigree, in which there are cases of tri-allelic TPOX genotypes. The subjects were apparently healthy with a normal biological development. We noticed six tri-allelic cases in this family, and all of them were women. Karyotype analysis showed no occurrence of partial 2p trisomy. All the tri-allelic cases had the genotype 8-10-11, probably due to three copies of the TPOX STR sequence in all cells (Type 2 tri-allelic pattern). Based on previous data we assumed the allele 10 as the TPOX third allele. The pedigree analyses show evidences that the TPOX extra-allele was the allele10, it is placed far from the main TPOX locus, and that there is a potential linkage of the TPOX extra-allele-10 with Xq. This was the first study that included a large pedigree analysis in order to understand the nature TPOX tri-allelic pattern.

Evaluation of genotoxic effects of benzene and its derivatives in workers of gas stations.

The search for reliable biomarkers of human exposure to benzene and its derivatives is still subject of research. Many of the proposed biomarkers have limitations ranging from the low sensitivity to the wide variability of results. Thus, the aim of our study was to assess the frequencies of chromosomal abnormalities (CA) and sister chromatid exchanges (SCE) in workers of gas stations, with (cases, n = 19) and without (local controls, n = 6) risk of exposure to benzene and its derivatives, comparing them with the results from the general population (external controls, n = 38). The blood dosages of benzene, toluene, and xylenes were measured in all participants. Blood solvent levels were compared with the findings obtained in cytogenetic evaluation and a research protocol which included data of the workplace, lifestyle, and health of the individuals. We did not detect the presence of benzene and its derivatives and did not find chromosomal damage that may be associated with the gas station activity in cases. Moreover, although we found an association of increased SCE and the working time in the local controls, the values found for SCE are within normal limits. Thus, our evaluation of SCE and CA reflected the levels of benzene and its derivatives observed in the blood. We believe, therefore, that SCE and CA may actually constitute possible tests for the evaluation of these exposures. However, we believe that further studies, including individuals at risk, are important to confirm this assertion.

Anormalidades cromossômicas entre pacientes com cardiopatia congênita / Chromosomal abnormalities in patients with congenital heart disease

FUNDAMENTO: As anormalidades cromossômicas (ACs) representam importante causa de cardiopatia congênita (CC). OBJETIVO: Determinar a frequência, os tipos e as características clínicas de ACs identificadas em uma amostra prospectiva e consecutiva de pacientes com CC. MÉTODO: Nossa amostra foi composta por pacientes com CC avaliados em sua primeira hospitalização em uma unidade cardíaca de tratamento intensivo de um hospital pediátrico de referência do sul do Brasil. Todos os pacientes foram submetidos à avaliação clínica e citogenética, através do cariótipo de alta resolução. Os defeitos cardíacos foram classificados segundo Botto e cols. Na análise estatística utilizou-se o qui-quadrado, o teste exato de Fisher e odds ratio (p < 0,05). RESULTADOS: Nossa amostra foi composta de 298 pacientes, 53,4% do sexo masculino, com idades variando de um dia a 14 anos. Anormalidades cromossômicas foram observadas em 50 pacientes (16,8%), sendo que 49 deles eram sindrômicos. Quanto às ACs, 44 delas (88%) eram numéricas (40 pacientes com +21, dois com +18, um com triplo X e um com 45,X) e seis (12%) estruturais [dois pacientes com der(14;21), +21, um com i(21q), um com dup(17p), um com del(6p) e um com add(18p)]. O grupo de CCs mais associado a ACs foi o do defeito de septo atrioventricular. CONCLUSÕES: ACs detectadas pelo cariótipo são frequentes entre pacientes com CC. Assim, os profissionais - especialmente aqueles que trabalham em serviços de cardiologia pediátrica - devem estar cientes das implicações que a realização do cariótipo pode trazer, tanto para o diagnóstico, tratamento e prognóstico desses pacientes como para o seu aconselhamento genético.

BACKGROUND: Chromosomal abnormalities (CAs) are an important cause of congenital heart disease (CHD). OBJECTIVE: Determine the frequency, types and clinical characteristics of CAs identified in a sample of prospective and consecutive patients with CHD. METHOD: Our sample consisted of patients with CHD evaluated during their first hospitalization in a cardiac intensive care unit of a pediatric referral hospital in Southern Brazil. All patients underwent clinical and cytogenetic assessment through high-resolution karyotype. CHDs were classified according to Botto et al. Chi-square, Fisher exact test and odds ratio were used in the statistical analysis (p < 0.05). RESULTS: Our sample consisted of 298 patients, 53.4% males, with age ranging from 1 day to 14 years. CAs were observed in 50 patients (16.8%), and 49 of them were syndromic. As for the CAs, 44 (88%) were numeric (40 patients with +21, 2 with +18, 1 with triple X and one with 45,X) and 6 (12%) structural [2 patients with der(14,21), +21, 1 with i(21q), 1 with dup(17p), 1 with del(6p) and 1 with add(18p)]. The group of CHDs more often associated with CAs was atrioventricular septal defect. CONCLUSIONS: CAs detected through karyotyping are frequent in patients with CHD. Thus, professionals, especially those working in Pediatric Cardiology Services, must be aware of the implications that performing the karyotype can bring to the diagnosis, treatment and prognosis and for genetic counseling of patients and families.