Disruption of the HIF-1 pathway in individuals with Ollier disease and Maffucci syndrome.

Ollier disease (OD) and Maffucci Syndrome (MS) are rare disorders characterized by multiple enchondromas, commonly causing bone deformities, limb length discrepancies, and pathological fractures. MS is distinguished from OD by the development of vascular anomalies. Both disorders are cancer predisposition syndromes with malignancies developing in ~50% of the individuals with OD or MS. Somatic gain-of-function variants in IDH1 and IDH2 have been described in the enchondromas, vascular anomalies and chondrosarcomas of approximately 80% of the individuals with OD and MS. To date, however, no investigation of germline causative variants for these diseases has been comprehensively performed. To search for germline causative variants, we performed whole exome sequencing or whole genome sequencing of blood or saliva DNA in 94 unrelated probands (68 trios). We found that 7 had rare germline missense variants in HIF1A, 6 had rare germline missense variants in VHL, and 3 had IDH1 variants including 2 with mosaic IDH1-p.Arg132His variant. A burden analysis using 94 probands assigned as cases and 2,054 unrelated individuals presenting no OD- or MS-related features as controls, found that variants in HIF1A, VHL, and IDH1 were all significantly enriched in cases compared to controls. To further investigate the role of HIF-1 pathway in the pathogenesis of OD and MS, we performed RNA sequencing of fibroblasts from 4 probands with OD or MS at normoxia and at hypoxia. When cultured in hypoxic conditions, both proband and control cells showed altered expression of a subset of HIF-1 regulated genes. However, the set of differentially expressed genes in proband fibroblasts included a significantly reduced number of HIF-1 regulated genes compared to controls. Our findings suggest that germline or early post-zygotic variants identified in HIF1A, VHL, and IDH1 in probands with OD and MS underlie the development of the phenotypic abnormalities in a subset of individuals with OD and MS, but extensive functional studies are needed to further confirm it.

Association between genetic polymorphisms and osteoarthritis development. Overview of systematic reviews.

OBJECTIVE: To identify, critically evaluate and synthesize the evidence obtained from systematic reviews on the association between genetic polymorphisms and osteoarthritis (OA) development. METHODS: Considering gene polymorphisms associated with OA susceptibility (risk or protection), a comprehensive search was conducted in the following databases, without date or language restrictions: MEDLINE, via Pubmed; Embase, via Elsevier; Cochrane Database of Systematic Reviews, via Wiley; Biblioteca Virtual em Saúde. Gray literature was also searched through the OpenGrey database. The AMSTAR-2 (Assessing the Methodological Quality of Systematic Reviews) was used to assess the methodological quality of the included systematic reviews. RESULTS: We included 14 systematic reviews of case-control studies comparing individuals with a radiographic diagnosis of all OA types and healthy controls, all submitted to the genetic examination of different polymorphisms in candidate genes. Meta-analyses showed a protective effect against knee and hand OA associated with GDF-5 gene (odds ratio [OR] 0.90, 95% confidence interval (CI) 0.85-0.95), and knee OA with ESRα gene (OR 0.63, 95% CI 1.26-1.97). SMAD3 gene was associated with knee and hip OA risk (OR 1.21. 95% CI 1.07-1.38) and MMP-1 gene was associated with temporomandibular OA (OR 1.58. 95% CI 1.26-1.97). CONCLUSION: Based on low-quality to critically-low-quality systematic reviews, some gene polymorphisms seem to be associated with risk or protection for OA. Further high-quality studies are needed to validate these hypotheses, contribute to disease understanding, and possibly help the decision-making related to early diagnosis and treatment options for OA. PROSPERO register CRD42021234231.

A novel variant in the COX15 gene causing a fatal infantile cardioencephalomyopathy: A case report with clinical and molecular review.

The cytochrome c-oxidase (COX) enzyme, also known as mitochondrial complex IV (MT-C4D), is a transmembrane protein complex found in mitochondria. COX deficiency is one of the most frequent causes of electron transport chain defects in humans. Therefore, high energy demand organs and tissues are affected in patients with mutations in the COX15 gene, with variable phenotypic expressiveness. We describe the case of a male newborn with hypertrophic cardiomyopathy and serum and cerebrospinal fluid hyperlacticaemia, whose exome sequencing revealed two variants in a compound heterozygous state: c.232G > A; p.(Gly78Arg), classified as likely pathogenic, and c.452C > G; p.(Ser151Ter), as pathogenic; the former never previously described in the literature.

Gomez-López-Hernández syndrome: A case report with clinical and molecular evaluation and literature review.

Gomez-López-Hernández syndrome (GLHS) is characterized by rhombencephalosynapsis (RES), alopecia, trigeminal anesthesia and a distinctive phenotype, including brachyturricephaly. It has been suggested that GLHS should be considered as part of the spectrum of RES-associated conditions that include alopecia, trigeminal anesthesia, and craniofacial anomalies, rather than a distinct entity. To the best of our knowledge, 57 patients with GLHS have been described. Despite its first description in 1979, the etiology of this syndrome remains unknown. Here, we describe, to our knowledge, the first case of a patient with GLHS who was molecularly evaluated and had been prenatally exposed to misoprostol. We also reviewed the clinical and morphological features of the patients described to date to better delineate the phenotype and focus on any evidence for adverse pregnancy outcomes or exposure, including teratogens.

Clinical, molecular, and pathological findings in a Neu-Laxova syndrome stillborn: A Brazilian case report.

Neu-Laxova syndrome (NLS) is a lethal genetic multiple congenital anomaly syndrome of unknown prevalence representing the severe spectrum of serine biosynthesis defects associated with PHGDH, PSAT1, or PSP gene mutations. The purpose of this study was to describe clinical/molecular and pathologic features of a NLS case caused by novel heterozygous missense variant in PHGDH gene identified in his consanguineous parents.

Atypical Prader-Willi and 15q13.3 Microdeletion Syndromes in a Patient with an Unbalanced Translocation.

Prader-Willi syndrome (PWS) and recurrent 15q13.3 microdeletion syndrome can be caused by genomic rearrangements in the complex 15q11q13 chromosomal region. Here, we describe the first female child with PWS and 15q13.3 microdeletion syndrome resulting from an unusual 10.7-Mb deletion from 15pter to 15q13.3 due to an unbalanced de novo 15;19 translocation. The patient presents with hypotonia, microcephaly, developmental delay with lack of speech, intellectual disability, happy demeanor, clinodactyly of the 4th and 5th fingers, and dysmorphic facial features discordant for PWS and consistent with an atypical phenotype.

Deletion 21pterq22.11: Report of a Patient with Dysmorphic Features, Hypertonia, and Café-au-Lait Macules and Review of the Literature.

Partial monosomy 21 results in a great variability of clinical features that may be associated with the size and location of the deletion. In this study, we report a 22-month-old girl who showed a 45,XX,add(12)(p13)dn,-21 karyotype. The final cytogenomic result was 45,XX,der(12)t(12;21)(p13;q22.11) dn,-21.arr[hg19] 21q11.2q22.11(14824453_33868129)×1 revealing a deletion from 21pter to 21q22.11. Clinical manifestation of the patient included hypertonia, a long philtrum, epicanthic folds, low-set ears, and café-au-lait macules - a phenotype considered as mild despite the relatively large size of the deletion compared to patients from the literature.

The phenotypic spectrum of congenital Zika syndrome.

In October 2015, Zika virus (ZIKV) outbreak the Brazilian Ministry of Health (MoH). In response, the Brazilian Society of Medical Genetics established a task force (SBGM-ZETF) to study the phenotype of infants born with microcephaly due to ZIKV congenital infection and delineate the phenotypic spectrum of this newly recognized teratogen. This study was based on the clinical evaluation and neuroimaging of 83 infants born during the period from July, 2015 to March, 2016 and registered by the SBGM-ZETF. All 83 infants had significant findings on neuroimaging consistent with ZIKV congenital infection and 12 had confirmed ZIKV IgM in CSF. A recognizable phenotype of microcephaly, anomalies of the shape of skull and redundancy of the scalp consistent with the Fetal Brain Disruption Sequence (FBDS) was present in 70% of infants, but was most often subtle. In addition, features consistent with fetal immobility, ranging from dimples (30.1%), distal hand/finger contractures (20.5%), and feet malpositions (15.7%), to generalized arthrogryposis (9.6%), were present in these infants. Some cases had milder microcephaly or even a normal head circumference (HC), and other less distinctive findings. The detailed observation of the dysmorphic and neurologic features in these infants provides insight into the mechanisms and timings of the brain disruption and the sequence of developmental anomalies that may occur after prenatal infection by the ZIKV.

Possible Association Between Zika Virus Infection and Microcephaly - Brazil, 2015.

In early 2015, an outbreak of Zika virus, a flavivirus transmitted by Aedes mosquitoes, was identified in northeast Brazil, an area where dengue virus was also circulating. By September, reports of an increase in the number of infants born with microcephaly in Zika virus-affected areas began to emerge, and Zika virus RNA was identified in the amniotic fluid of two women whose fetuses had been found to have microcephaly by prenatal ultrasound. The Brazil Ministry of Health (MoH) established a task force to investigate the possible association of microcephaly with Zika virus infection during pregnancy and a registry for incident microcephaly cases (head circumference ≥2 standard deviations [SD] below the mean for sex and gestational age at birth) and pregnancy outcomes among women suspected to have had Zika virus infection during pregnancy. Among a cohort of 35 infants with microcephaly born during August-October 2015 in eight of Brazil's 26 states and reported to the registry, the mothers of all 35 had lived in or visited Zika virus-affected areas during pregnancy, 25 (71%) infants had severe microcephaly (head circumference >3 SD below the mean for sex and gestational age), 17 (49%) had at least one neurologic abnormality, and among 27 infants who had neuroimaging studies, all had abnormalities. Tests for other congenital infections were negative. All infants had a lumbar puncture as part of the evaluation and cerebrospinal fluid (CSF) samples were sent to a reference laboratory in Brazil for Zika virus testing; results are not yet available. Further studies are needed to confirm the association of microcephaly with Zika virus infection during pregnancy and to understand any other adverse pregnancy outcomes associated with Zika virus infection. Pregnant women in Zika virus-affected areas should protect themselves from mosquito bites by using air conditioning, screens, or nets when indoors, wearing long sleeves and pants, using permethrin-treated clothing and gear, and using insect repellents when outdoors. Pregnant and lactating women can use all U.S. Environmental Protection Agency (EPA)-registered insect repellents according to the product label.

[Congenital Anomalies Detected at Birth in Newborns of Adolescent Women]. / Anomalias Congénitas Identificadas ao Nascimento em Recém-Nascidos de Mulheres Adolescentes.

INTRODUCTION: To analyze the prevalence of congenital anomalies detected at birth among children of pregnant adolescents, emphasizing the most common types and the time of diagnosis. MATERIAL AND METHODS: Retrospective study of type census, in which were analyzed in all newborns, living or dead, weighing more than 500 g of women who gave birth at Hospital São Paulo in a period of six years. The fetuses bearing anomalies were identified prenatally or through postnatal physical examination period, according to the criteria of the Latin American Collaborative Study of Congenital Malformations. The results were expressed descriptively using absolute and relative values, the prevalence of anomalies was calculated, as well as the comparison between groups using nonparametric tests. RESULTS: We analyzed 6 257 pregnancies, of which 577 newborns had some congenital anomaly identified at birth (prevalence 9.2%). Among these 6 257, 907 were adolescents, which showed a 9.9% prevalence of anomalies among their newborns. There was no significant difference between the presence of abnormalities in newborns of adolescents and women with age greater than or equal to 20 years. About 56% of congenital anomalies were diagnosed in the prenatal period. We observed a higher prevalence of defects of neural tube between newborns of adolescents (p = 0.027). DISCUSSION: We observed high rate of deliveries in adolescents, higher than developed countries. We observed also high frequency of congenital anomalies in newborns, probably because our tertiary reference center. The high prevalence of neural tube defect among young pregnant women could be explained by the absent of acid folic supplementation in non-planned gestations which is typical of adolescents. CONCLUSION: The prevalence and time of diagnosis of congenital anomalies showed similar behavior among newborns of teenagers and women with age greater than or equal to 20 years, except for the defects of the neural tube, which were more prevalent among newborns of teenagers.

Introdução: Analisar a prevalência das anomalias congénitas, detetadas no nascimento, entre filhos de gestantes adolescentes, enfatizando os tipos mais comuns e a época do diagnóstico. Material e Métodos: Estudo retrospetivo do tipo censo, no qual foram analisados todos recém-nascidos, vivos ou mortos, com peso superior a 500 g, de mulheres que tiveram o parto no Hospital São Paulo num período de seis anos. Os produtos da conceção portadores de anomalias foram identificados no período pré-natal ou através do exame físico pós-natal, segundo os critérios do Estudo Colaborativo Latino-Americano das Malformações Congênitas. Os resultados são apresentados de forma descritiva através de valores absolutos e relativos, calcula-se a prevalência das anomalias e comparam-se os diferentes grupos recorrendo a testes não paramétricos. Resultados: Foram analisadas 6 257 gestações, das quais 577 resultaram em recém-nascidos com alguma anomalia congénita identificada no nascimento (prevalência de 9,2%). Do total de gestações, 907 eram de adolescentes (idade inferior a 20 anos), para as quais se verificou uma prevalência de anomalias nos recém-nascidos de 9,9%. Comparando os recém-nascidos de adolescentes com os das mulheres com idade superior a 20 anos, apenas se encontrou diferença estatisticamente significativa para a prevalência dos defeitos do tubo neural (p = 0,027). Discussão: Observamos uma alta taxa de partos em adolescentes, acima das taxas dos países desenvolvidos. Observamos também alta frequência de anomalias congénitas em recém-nascidos, provavelmente por sermos um serviço terciário de referência. A elevada prevalência dos defeitos do tubo neural entre grávidas jovens pode ser explicada pela não suplementação pré-concecional de ácido fólico em gravidezes não planeadas, como é característico nas adolescentes.Conclusão: A prevalência e momento do diagnóstico das anomalias congénitas em recém-nascidos apresentam comportamentos semelhantes entre grávidas com idade inferior ou superior a 20 anos, exceto para os defeitos do tubo neural, de maior prevalência nos recém-nascidos das grávidas adolescentes.

Investigating 22q11.2 deletion and other chromosomal aberrations in fetuses with heart defects detected by prenatal echocardiography.

Congenital heart disease (CHD) is the most common birth defect and the leading cause of mortality in the first year of life. In fetuses with a heart defect, chromosomal abnormalities are very frequent. Besides aneuploidy, 22q11.2 deletion is one of the most recognizable chromosomal abnormalities causing CHD. The frequency of this abnormality varies in nonselected populations. This study aimed to investigate the incidence of the 22q11.2 deletion and other chromosomal alterations in a Brazilian sample of fetuses with structural cardiac anomalies detected by fetal echocardiography. In a prospective study, 68 fetuses with a heart defect were evaluated. Prenatal detection of cardiac abnormalities led to identification of aneuploidy or structural chromosomal anomaly in 35.3% of these cases. None of the fetuses with apparently normal karyotypes had a 22q11.2 deletion. The heart defects most frequently associated with chromosomal abnormalities were atrioventricular septal defect (AVSD), ventricular septal defect (VSD), and tetralogy of Fallot. Autosomal trisomies 18 and 21 were the most common chromosomal abnormalities. The study results support the strong association of chromosome alterations and cardiac malformation, especially in AVSD and VSD, for which a chromosome investigation is indicated. In fetuses with an isolated conotruncal cardiopathy, fluorescence in situ hybridization (FISH) to investigate a 22q11.2 deletion is not indicated.

[Use of the Internet to report congenital malformations on birth certificates at four public maternity hospitals in the city of São Paulo, Brazil]. / A utilização da Internet na notificação dos defeitos congênitos na Declaração de Nascido Vivo em quatro maternidades públicas do Município de São Paulo, Brasil.

The aim of this study was to improve the completion of item 34 on birth certificates at four maternity hospitals in the city of São Paulo, Brazil, in the year 2008. The database of the Municipal Health Department's Information System on Live Births was used to monitor trends in reporting birth defects. An electronic web-based medical record was used to refer indeterminate cases to a leading medical genetics referral center. The electronic medical record contained the patient history, physical examination, and photographs of the newborn. Four maternity hospitals were assessed, with a total of 10,000 births during the year. None of the four hospitals had a staff geneticist. According to the Information System on Live Births, there was an increase in the number of birth defects reported by the four maternity hospitals when compared to previous years and to records for the city of São Paulo as a whole. Based on the findings, the web-based referral and counter-referral method proved efficient.

A utilização da Internet na notificacao dos defeitos congenitos na Declaracao de Nascido Vivo em quatro maternidades publicas do municipio de Sao Paulo, Brasil / Use of the Internet to report congenital malformations on birth certificates at four public maternity hospitals in the city of Sao Paulo, Brazil

O objetivo foi aumentar a frequencia da notificacao de anomalias congenitas no campo 34 da Declaracao de Nascido Vivo em quatro maternidades do Municipio de Sao Paulo, Brasil, ao longo do ano de 2008. Utilizamos o banco de dados do Sistema de Informacoes sobre Nascidos Vivos da Secretaria Municipal de Saude de Sao Paulo para acompanhar a evolucao dos registros dos defeitos congenitos. Mediante prontuario eletronico, via Internet, os casos suspeitos eram enviados para um centro de referencia em genetica medica. O prontuario eletronico contem anamnese, exame fisico e fotos do recem-nascido. O estudo ocorreu em quatro maternidades com uma amostra total de 10 mil nascimentos no ano e que nao apresentam medico geneticista. Houve aumento da notificacao dos defeitos congenitos nas quatro maternidades onde o estudo foi realizado quando comparado com os anos anteriores e com o registro do Municipio de Sao Paulo. O metodo de referencia e contra-referencia utilizando a Internet mostrou-se eficaz.

The aim of this study was to improve the completion of item 34 on birth certificates at four maternity hospitals in the city of Sao Paulo, Brazil, in the year 2008. The database of the Municipal Health Department's Information System on Live Births was used to monitor trends in reporting birth defects. An electronic web-based medical record was used to refer indeterminate cases to a leading medical genetics referral center. The electronic medical record contained the patient history, physical examination, and photographs of the newborn. Four maternity hospitals were assessed, with a total of 10,000 births during the year. None of the four hospitals had a staff geneticist. According to the Information System on Live Births, there was an increase in the number of birth defects reported by the four maternity hospitals when compared to previous years and to records for the city of Sao Paulo as a whole. Based on the findings, the web-based referral and counter-referral method proved efficient.

Novel mutations in the TBX5 gene in patients with Holt-Oram Syndrome.

The Holt-Oram syndrome (HOS) is an autosomal dominant condition characterized by upper limb and cardiac malformations. Mutations in the TBX5 gene cause HOS and have also been associated with isolated heart and arm defects. Interactions between the TBX5, GATA4 and NKX2.5 proteins have been reported in humans. We screened the TBX5, GATA4, and NKX2.5 genes for mutations, by direct sequencing, in 32 unrelated patients presenting classical (8) or atypical HOS (1), isolated congenital heart defects (16) or isolated upper-limb malformations (7). Pathogenic mutations in the TBX5 gene were found in four HOS patients, including two new mutations (c.374delG; c.678G > T) in typical patients, and the hotspot mutation c.835C > T in two patients, one of them with an atypical HOS phenotype involving lower-limb malformations. Two new mutations in the GATA4 gene were found in association with isolated upper-limb malformations, but their clinical significance remains to be established. A previously described possibly pathogenic mutation in the NKX2.5 gene (c.73C > 7) was detected in a patient with isolated heart malformations and also in his clinically normal father.

Novel mutations in the TBX5 gene in patients with Holt-Oram Syndrome

The Holt-Oram syndrome (HOS) is an autosomal dominant condition characterized by upper limb and cardiac malformations. Mutations in the TBX5 gene cause HOS and have also been associated with isolated heart and arm defects. Interactions between the TBX5, GATA4 and NKX2.5 proteins have been reported in humans. We screened the TBX5, GATA4, and NKX2.5 genes for mutations, by direct sequencing, in 32 unrelated patients presenting classical (8) or atypical HOS (1), isolated congenital heart defects (16) or isolated upper-limb malformations (7). Pathogenic mutations in the TBX5 gene were found in four HOS patients, including two new mutations (c.374delG; c.678G > T) in typical patients, and the hotspot mutation c.835C > T in two patients, one of them with an atypical HOS phenotype involving lower-limb malformations. Two new mutations in the GATA4 gene were found in association with isolated upper-limb malformations, but their clinical significance remains to be established. A previously described possibly pathogenic mutation in the NKX2.5 gene (c.73C > 7) was detected in a patient with isolated heart malformations and also in his clinically normal father.

22q11.2 deletion in patients with conotruncal heart defect and del22q syndrome phenotype.

BACKGROUND: The 22q11.2 deletion syndrome is the most frequent human microdeletion syndrome. The phenotype is highly variable, being characterized by conotruncal heart defect, facial dysmorphisms, velopharyngeal insufficiency, learning difficulties and mental retardation. OBJECTIVE: The objective of this study was to investigate the frequency of deletion 22q11.2 in a Brazilian sample of individuals with isolated conotruncal heart defect and 22q11.2 deletion syndrome phenotype. METHODS: Twenty-nine patients were studied by classical cytogenetics, by fluorescence in situ hybridization (FISH), and by molecular techniques. RESULTS: Cytogenetic analysis by G-banding revealed a normal karyotype in all patients except one who presented a 47,XX,+idic(22)(q11.2) karyotype. Using molecular techniques, a deletion was observed in 25% of the patients, all exhibiting a 22q11.2 deletion syndrome phenotype. In none of the cases the deletion was inherited from the parents. The frequency of 22q11.2 deletion was higher in patients with the clinical spectrum of the 22q11.2 deletion syndrome than in patients with isolated conotruncal heart defect. CONCLUSION: Investigating the presence of the deletion and its correlation with the patients' clinical data can help the patients and their families to have a better genetic counseling and more adequate clinical follow-up.

Interrupted aortic arch type B in A patient with cat eye syndrome.

We report a patient with cat eye syndrome and interrupted aortic arch type B, a typical finding in the 22q11.2 deletion syndrome. Chromosomal analysis and fluorescent in situ hybridization (FISH) showed a supernumerary bisatellited isodicentric marker chromosome derived from chromosome 22. The segment from 22pter to 22q11.2 in the supernumerary chromosome found in our patient does not overlap with the region deleted in patients with the 22q11.2 deletion syndrome. However, the finding of an interrupted aortic arch type B is unusual in CES, although it is a frequent heart defect in the 22q11 deletion syndrome.

Interrupção do arco aórtico tipo B em uma paciente com síndrome de olho de gato / Interrupted aortic arch type B in A patient with cat eye syndrome / Interrupción del arco aórtico tipo B en una paciente con síndrome del ojo de gato

Relatamos um caso de paciente com Síndrome do Olho de Gato (Cat Eye Syndrome-CES) e interrupção do arco aórtico tipo B, um achado típico na síndrome da deleção 22q11.2. A análise cromossômica e a técnica de hibridização fluorescente in situ (FISH) mostraram um cromossomo marcador isodicêntrico supranumerário com bi-satélite derivado do cromossomo 22. O segmento de 22pter a 22q11.2 no cromossomo supranumerário encontrado em nosso paciente não estava em sobreposição com a região deletada em pacientes com a síndrome da deleção 22q11.2. Entretanto, o achado de interrupção do arco aórtico tipo B não é usual na CES, mas é um defeito cardíaco freqüente na síndrome da deleção 22q11.

We report a patient with cat eye syndrome and interrupted aortic arch type B, a typical finding in the 22q11.2 deletion syndrome. Chromosomal analysis and fluorescent in situ hybridization (FISH) showed a supernumerary bisatellited isodicentric marker chromosome derived from chromosome 22. The segment from 22pter to 22q11.2 in the supernumerary chromosome found in our patient does not overlap with the region deleted in patients with the 22q11.2 deletion syndrome. However, the finding of an interrupted aortic arch type B is unusual in CES, although it is a frequent heart defect in the 22q11 deletion syndrome.

Informamos un caso de paciente con Síndrome de Ojo de Gato (Cat Eye Syndrome-CES) e Interrupción del Arco Aórtico tipo B, un hallazgo típico en el síndrome de la deleción 22q11.2. El análisis cromosómico y la técnica de hibridación in situ fluorescente (FISH) mostraron un cromosoma marcador isodicéntrico supernumerario bisatelitado derivado del cromosoma 22. El segmento de 22pter a 22q11.2 en el cromosoma supernumerario encontrado en nuestro paciente no estaba en sobreposición con la región deletada en pacientes con el síndrome de la deleción 22q11.2. Con todo, el hallazgo de interrupción del arco aórtico tipo B no es usual en el CES, sino que es un defecto cardíaco frecuente en el síndrome de deleción 22q11.

Deleção 22q11.2 em pacientes com defeito cardíaco conotruncal e fenótipo da síndrome da deleção 22q11.2 / Deleción 22q11.2 en pacientes con defecto cardiaco conotruncal y fenotipo del síndrome de la deleción 22q11.2 / 22q11.2 deletion in patients with conotruncal heart defect and del22q syndrome phenotype

FUNDAMENTO: A síndrome da deleção 22q11.2 é a mais freqüente síndrome de microdeleção humana. O fenótipo é altamente variável e caracterizado por defeito cardíaco conotruncal, dismorfias faciais, insuficiência velofaríngea, dificuldade de aprendizagem e retardo mental. OBJETIVO: O objetivo deste trabalho foi investigar a freqüência da deleção 22q11.2 em uma amostra brasileira de indivíduos portadores de cardiopatia conontrucal isolada e do fenótipo da síndrome da deleção 22q11.2. MÉTODOS: Vinte e nove pacientes foram estudados por meio de citogenética clássica, por hibridação in situ fluorescente (FISH) e por técnicas moleculares. RESULTADOS: A análise citogenética por meio de bandamento G revelou cariótipo normal em todos os pacientes, com exceção de um que apresentou cariótipo 47,XX,+idic(22)(q11.2). Com o uso de técnicas moleculares, a deleção foi observada em 25 por cento dos pacientes, todos portadores do fenótipo da síndrome da deleção 22q11.2. Em nenhum dos casos, a deleção foi herdada dos pais. A freqüência da deleção 22q11.2 foi maior no grupo de pacientes portadores do espectro clínico da síndrome da deleção 22q11.2 do que no grupo de pacientes com cardiopatia conotruncal isolada. CONCLUSÃO: A investigação da presença da deleção e sua correlação com os dados clínicos dos pacientes podem auxiliar os pacientes e suas famílias a terem um melhor aconselhamento genético e um seguimento clínico mais adequado.

BACKGROUND: The 22q11.2 deletion syndrome is the most frequent human microdeletion syndrome. The phenotype is highly variable, being characterized by conotruncal heart defect, facial dysmorphisms, velopharyngeal insufficiency, learning difficulties and mental retardation. OBJECTIVE: The objective of this study was to investigate the frequency of deletion 22q11.2 in a Brazilian sample of individuals with isolated conotruncal heart defect and 22q11.2 deletion syndrome phenotype. METHODS: Twenty-nine patients were studied by classical cytogenetics, by fluorescence in situ hybridization (FISH), and by molecular techniques. RESULTS: Cytogenetic analysis by G-banding revealed a normal karyotype in all patients except one who presented a 47,XX,+idic(22)(q11.2) karyotype. Using molecular techniques, a deletion was observed in 25 percent of the patients, all exhibiting a 22q11.2 deletion syndrome phenotype. In none of the cases the deletion was inherited from the parents. The frequency of 22q11.2 deletion was higher in patients with the clinical spectrum of the 22q11.2 deletion syndrome than in patients with isolated conotruncal heart defect. CONCLUSION: Investigating the presence of the deletion and its correlation with the patients' clinical data can help the patients and their families to have a better genetic counseling and more adequate clinical follow-up.

FUNDAMENTO: El síndrome de la deleción 22q11.2 es el más frecuente síndrome de microdeleción humana. El fenotipo, altamente variable, se caracteriza por defecto cardiaco conotruncal, dismorfias faciales, insuficiencia velofaríngea, dificultad de aprendizaje y retardo mental. OBJETIVO: El objetivo de este trabajo fue investigar la frecuencia tanto de la deleción 22q11.2 en una muestra brasileña de individuos portadores de cardiopatía conotrucal aislada, como del fenotipo del síndrome de la delación 22q11.2. MÉTODOS: Se estudiaron a 29 pacientes por medio de citogenética clásica, por hibridación in situ fluorescente (FISH) y también por técnicas moleculares. RESULTADOS: El análisis citogenético por medio de bandeo G reveló cariotipo normal en todos los pacientes, con excepción de uno, que presentó cariotipo 47,XX,+idic(22)(q11.2). Con la utilización de técnicas moleculares, se observó la deleción en el 25 por ciento de los pacientes, todos portadores del fenotipo del síndrome de la deleción 22q11.2. En ningún de los casos, la deleción se heredó de los padres. La frecuencia de la deleción 22q11.2 en el grupo de pacientes portadores del espectro clínico de este síndrome resultó mayor que en el grupo de pacientes con cardiopatía conotruncal aislada. CONCLUSIÓN: La investigación de la presencia de deleción y su correlación con los datos clínicos de los pacientes pueden auxiliar los pacientes y sus familias a tener un mejor aconsejamiento genético, así como un seguimiento clínico más adecuado.