Investigação Citogenômica de Crianças com Doença Cardíaca Congênita: Experiência de um Centro no Brasil / Cytogenomics Investigation of Infants with Congenital Heart Disease: Experience of a Brazilian Center

Resumo Fundamento Algumas síndromes têm características específicas e facilmente reconhecíveis, enquanto outras podem ser mais complexas de se identificar e podem apresentar diferentes manifestações fenotípicas, por exemplo. Um diagnóstico etiológico é importante para entender a natureza da doença, para estabelecer o prognóstico e para começar o tratamento, permitindo a inclusão de pacientes na sociedade e reduzindo o custo financeiro dessas doenças. Objetivo A proposta inicial deste estudo foi a triagem citogenética para detectar a síndrome de deleção 22q11.2 (SD22q11.2) em recém-nascidos e crianças com doença cardíaca congênita utilizando a técnica da amplificação multiplex de sondas dependente de ligação (MLPA). Assim, por meio da pesquisa, outras mudanças genômicas foram identificadas nesses pacientes cardíacos. Nosso objetivo se estendeu a investigar essas outras mudanças citogenéticas. Métodos Investigamos 118 recém-nascidos com doenças cardíacas congênitas nascidos consecutivamente durante um ano, utilizando a técnica da MLPA. Resultados A técnica da MLPA permitiu a detecção da SD22q11.2 em 10/118 pacientes (8,5%). Outras alterações genômicas foram identificadas em 6/118 pacientes (5%): 1p36 del, 8p23 del (2 casos), 7q dup, 12 dup e 8q24 dup. Conclusão Este estudo ressalta a relevância da detecção de alterações genômicas que estão presentes em recém-nascidos e crianças com doenças cardíacas congênitas por meio de ferramentas citogenômicas.

Abstract Background Some syndromes have specific and easily recognizable features, while others may be more complex to identify and may present different phenotypic manifestations, for example. An etiological diagnosis is important to understand the nature of the disease, to establish the prognosis and to start the treatment, allowing the inclusion of patients in society and reducing the financial cost of such diseases. Objective The initial proposal of this study was cytogenetic screening for the detection of the 22q11.2 deletion syndrome in consecutive newborns and infants with congenital heart disease using the multiplex ligation-dependent probe amplification (MLPA) technique. Therefore, throughout our research, other genomic alterations were identified in these cardiac patients. Thus, our objective was extended to investigate these other cytogenetic alterations. Methods We investigated 118 neonates with congenital heart diseases born consecutively during one year using the MLPA technique. Results The MLPA technique allowed the detection of 22q11.2DS in 10/118 patients (8.5%). Other genomic alterations were also identified in 6/118 patients (5%): 1p36 del, 8p23 del (2 cases), 7q dup, 12 dup and 8q24 dup. Conclusion This study highlights the relevance of detecting genomic alterations that are present in newborns and infants with congenital cardiac diseases using cytogenomic tools.

Congenital Heart Disease Revealing Familial 22q11 Deletion Syndrome

Abstract Congenital heart defects are the most common birth defects and the leading cause of mortality in the first year of life. It is well known that the 22q11 deletion syndrome (22q11DS) is the most common microdeletion syndrome in humans and that congenial heart diseases (CHDs) are one of the most common phenotypic manifestations. However, it should be noted that the 22q11 deletion was also found in a significant number of patients with isolated CHD. The 22q11DS phenotype may include cardiovascular anomalies, palatal abnormalities, nasal voice, immune deficiency, endocrine dysfunctions, a varying degree of cognitive deficits and intellectual disabilities, velopharyngeal insufficiency, and characteristic craniofacial dysmorphism. This condition affects about 1 in 4,000 live births, making 22q11DS the most common microdeletion syndrome in humans. Here we describe the cases of three children who were referred to the clinical hospital center with the diagnosis of CHD, but with no direct signs of 22q11DS. Investigation of familial data led us to suspect that the mothers could be carriers of 22q11DS. The multiplex ligation-dependent probe amplification (MLPA) testing confirmed that the patients and mothers exhibited 3 Mb 22q11 deletions, which justified the clinical signs in the mothers and the CHD in children. In the presence of a few characteristics that are common of a spectrum of some known syndromes, a familial examination can provide clues to a definitive diagnosis, as well as to the prevention of diseases and genetic counseling of these patients.

Cardiopatías congénitas asociadas a la microdeleción 22q11. 2, en un hospital pediátrico / Congenital heart defects associated with a 22q11. 2 microdeletion at a pediatric hospital

Introducción: El síndrome de deleción 22q11.2, también llamado síndrome Velo-Cardio-Facial (VCFS/del22q11.2) o síndrome de DiGeorge, es una entidad causada por una anomalía cromosómica, deleción en la región q11.2 (brazo largo) del cromosoma 22. Se trata de una enfermedad multisistémica de expresión variable que afecta el aparato cardiovascular, la inmunidad, las funciones endocrinológicas, la cavidad oral, el desarrollo neurocognitivo, con una expresión facial particular. La prevalencia estimada es de 1:2000/4000. Objetivos: Identificar y describir las cardiopatías congénitas más frecuentemente asociadas a pacientes con síndrome de microdeleción 22q11.2. Materiales y métodos: Estudio descriptivo, transversal y retrospectivo que analiza los pacientes con diagnóstico de microdeleción 22q11.2 atendidos en el Hospital Garrahan desde Octubre de 1998 hasta Febrero 2018. El criterio diagnóstico fueron signos clínicos compatibles y la presencia de la microdeleción 22q11.2 por técnica de FISH o MLPA. Resultados: Población: 321 pacientes, 151 Femeninos (47%) 170 Masculinos (53%). Rango etario: 0 a 197 meses (1 día a 16,4 años). Mediana de edad al diagnóstico clínico: 31 meses. El 74,4% (239/321) de los pacientes evaluados con microdeleción 22q11.2 tuvieron cardiopatías congénitas asociadas a facies peculiar. Las cardiopatías congénitas más frecuentemente asociadas fueron conotroncales. De los pacientes con cardiopatías congénitas el 68,6% requirió cirugía cardiovascular. Fallecieron 24 pacientes (10%) con cardiopatías congénitas asociadas y en el 93% la causa de muerte estuvo relacionada a la afección cardiológica. Conclusiones: Los pacientes con microdeleción 22q11.2 se asocian con un alto porcentaje de cardiopatías congénitas, la gran mayoría son complejas (conotroncales) y requieren resolución quirúrgica en los primeros años de vida. Es de vital importancia la evaluación multidisciplinaria de este grupo especial de pacientes con cardiopatía asociada a otras alteraciones extra cardíacas para el diagnóstico precoz y tratamiento oportuno (AU)

Introduction: 22q11.2 deletion syndrome, also called velocardiofacial syndrome (VCFS/del22q11.2) or DiGeorge syndrome, is a condition caused by chromosomal abnormality, a deletion in the q11.2 region (long arm) of chromosome 22. VCFS is a multisystem disease of variable expression that affects the cardiovascular, immune, and endocrine systems, the oral cavity, neurocognitive development, and is associated with specific facial features. The estimated prevalence is 1:2000/4000. Objectives: To identify and describe the most common congenital heart defects associated with 22q11.2 micro-deletion syndrome. Materials and methods: Descriptive, cross-sectional, and retrospective study analyzing patients diagnosed with a 22q11.2 microdeletion seen at Garrahan Hospital from October 1998 to February 2018. Diagnostic criteria were compatible clinical signs and the presence of a 22q11.2 microdeletion identified by FISH or MLPA. Results: Population: 321 patients, 151 female (47%) and 170 Male (53%). Age range: 0 to 197 months (1 day to 16.4 years). Median age at clinical diagnosis: 31 months. Overall, 74.4% (239/321) of patients with a 22q11.2 microdeletion had congenital heart defects associated with a peculiar facies. The most commonly associated congenital heart defects were conotruncal. Of the patients with congenital heart defects, 68.6% required cardiovascular surgery. Of the patients with congenital heart defects 24 patients died (10%) and in 93% the cause of death was related to the heart disease (p 0.002). Conclusions: A high percentage of patients with a 22q11.2 microdeletion have congenital heart defects, which are complex (conotruncal) in the majority, requiring surgical treatment in the first years of life. Multidisciplinary evaluation of this special group of patients with heart defects associated with other extracardiac disorders is essential for an early diagnosis and timely treatment (AU)

22q11.2 deletion detected by in situ hybridization in Mexican patients with velocardiofacial syndrome-like features / Deleción 22q11.2 detectada por hibridación in situ en pacientes mexicanos con características clínicas similares al síndrome velocardiofacial

Abstract Introduction: Deletion 22q11.2 occurs in 1:4,000-1:6,000 live births while 10p13p14 deletion is found in 1:200,000 newborns. Both deletions have similar clinical features such as congenital heart disease and immunological anomalies. Objective: We looked for a 22q11.2 deletion in Mexican patients with craniofacial dysmorphisms suggestive of DiGeorge or velocardiofacial syndromes and at least one major phenotypic feature (cardiac anomaly, immune deficiency, palatal defects or development delay). Methods: A prospective study of 39 patients recruited in 2012-2015 at the Instituto Mexicano del Seguro Social at Guadalajara, Mexico. The patients with velocardiofacial syndrome-like features or a confirmed tetralogy of Fallot (TOF) or complex cardiopathy were studied by G-banding and fluorescence in situ hybridization (FISH) with a dual TUPLE1(HIRA)/ARSA or TUPLE1(22q11)/22q13(SHANK3) probe, six patients without the 22q11.2 deletion (arbitrarily selected) were tested with the dual DiGeorge II (10p14)/D10Z1 probe. Results: Twenty-two patients (7 males and 15 females) had the 22q11.2 deletion and 17/39 did not have it; no patient had a 10p loss. Among the 22 deleted patients, 19 had congenital heart disease (mostly TOF). Twelve patients without deletion had heart defects such as TOF (4/12), isolate ventricular septal defect (2/12) or other disorders (6/12). Conclusion: In our small sample about ~56% of the patients, regardless of the clinical diagnosis, had the expected 22q11.2 deletion. We remark the importance of early cytogenetic diagnosis in order to achieve a proper integral management of the patients and their families.

Resumen Introducción: La deleción 22q11.2 ocurre con una frecuencia de 1:4,000-1:6,000 nacidos vivos, mientras que la deleción 10p13p14 es detectada en 1:200,000 recién nacidos. Ambas deleciones comparten características clínicas similares tales como defectos cardiacos congénitos y anomalías inmunológicas. Objetivo: Identificar la deleción 22q11.2 en pacientes mexicanos con dismorfismo craneofacial sugestivo de síndrome DiGeorge o velocardiofacial y por lo menos con una característica clínica mayor (anomalía cardiaca, deficiencia inmunológica, defectos en paladar o retardo en el desarrollo) Métodos: Estudio prospectivo de 39 pacientes captados entre 2012-2015 en el Instituto Mexicano del Seguro Social en Guadalajara, México. Los pacientes con características clínicas sugerentes de síndrome velocardiofacial o diagnostico confirmado de tetralogía de Fallot (TOF) o cardiopatía compleja fueron estudiados por bandas G y por hibridación in situ fluorescente (FISH) con una sonda dual TUPLE1(HIRA)/ARSA o TUPLE1(22q11)/22q13(SHANK3), seis pacientes sin la deleción 22q11.2 (seleccionados arbitrariamente) fueron estudiados con la sonda dual DiGeorge II (10p14)/D10Z1. Resultados: Veintidós pacientes (7 hombres y 15 mujeres) tuvieron la deleción 22q11.2 y 17/39 no la tuvieron, ningún paciente tuvo la pérdida de 10p. Entre los 22 pacientes delecionados, 19 tuvieron defecto cardiaco congénito (principalmente TOF). Doce pacientes sin la deleción tuvieron defectos cardiacos congénitos como TOF (4/12), defecto del septo ventricular aislado (2/12) y otros trastornos cardiacos (6/12). Conclusión: En nuestra pequeña muestra, alrededor de ~56% de los pacientes, independientemente de su diagnostico clínico, tuvieron la deleción 22q11.2 esperada. Resaltamos la importancia del diagnóstico citogenético temprano para determinar un apropiado manejo integral para el paciente y sus familiares.

El síndrome 22q11.2D S como un subtipo genético de esquizofrenia / 22q11.2 DS Syndrome as a Genetic Subtype of Schizophrenia

Introducción: El síndrome de deleción 22q11.2 (22q11.2 DS) se produce por microdeleciones del brazo largo del cromosoma 22 en la región q11.2. Después del síndrome de Down, es el segundo síndrome genético más común. En pacientes con esquizofrenia, el 22q11.2 DS tiene una prevalencia del 2%, mientras que en personas con esquizofrenia seleccionadas por características físicas específicas, aumenta un 32-53%. Objetivo: Describir las generalidades del 22q11.2 DS, sus características clínicas, los aspectos genético-moleculares y la frecuencia de la microdeleción de 22q11.2 en diferentes poblaciones. Métodos: Se hizo una revisión desde 1967 hasta 2013 en bases de datos de publicaciones científicas, orientada a recopilar artículos sobre el 22q11.2 DS y su relación con la esquizofrenia. Resultados: El 22q11.2 DS es una entidad genética que se asocia a un fenotipo variable relacionado con defectos congénitos en diferentes tejidos y órganos, así como a una alta frecuencia de trastornos psiquiátricos, particularmente la esquizofrenia. Se ha identificado alta prevalencia en grupos de personas con esquizofrenia seleccionadas por características sindrómicas comunes, como dificultades de aprendizaje, rasgos faciales típicos, anomalías palatales y defectos cardiacos congénitos. Las técnicas de FISH, qPCR, MLPA y, recientemente, aCGH y NGS se están usando para diagnosticar esta microdeleción. Conclusiones: En la práctica clínica es importante tener presente que las personas con 22q11.2 DS tienen alto riesgo de sufrir esquizofrenia, ya que la región 22q11.2 alberga genes candidatos relacionados con vulnerabilidad a esquizofrenia. Se considera que la concomitancia de esta enfermedad y 22q11.2 DS representa un subtipo genético de esquizofrenia. y métodos citogenéticos y moleculares para diagnosticar a este grupo de pacientes y optimizar un abordaje multidisciplinario en su seguimiento.

Introduction: The 22q11.2 deletion syndrome (22q11.2 DS) is associated with the microdeletion of this chromosomal region, and represents the second most common genetic syndrome after Down's syndrome. In patients with schizophrenia, 22q11.2 DS has a prevalence of 2%, and in selected groups can be increased to between 32-53%. Objective: To describe the generalities of 22q11.2 DS syndrome as a genetic subtype of schizophrenia, its clinical characteristics, molecular genetic aspects, and frequency in different populations. Methods: A review was performed from 1967 to 2013 in scientific databases, compiling articles about 22q11.2 DS syndrome and its association with schizophrenia. Results: The 22q11.2 DS syndrome has a variable phenotype associated with other genetic syndromes, birth defects in many tissues and organs, and a high rate of psychiatric disorders, particularly schizophrenia. Likewise, it has been identified in clinical populations with schizophrenia selected by the presence of common syndromic characteristics. FISH, qPCR and MLPA techniques, and recently, aCGH and NGS technologies, are being used to diagnose this microdeletion. Conclusions: It is important in clinical practice to remember that people suffering the 22q11.2 DS have a high genetic risk for developing schizophrenia, and it is considered that the simultaneous presence of this disease and 22q11.2 DS represents a genetic subtype of schizophrenia. There are clear phenotypic criteria, molecular and cytogenetic methods to diagnose this group of patients, and to optimize a multidisciplinary approach in their monitoring.

Alta prevalencia de hernias abdominales en pacientes con síndrome velocardiofacial / High incidence of abdominal wall hernias in patients with velocardiofacial syndrome

Velocardiofacial syndrome (VCFS) is due to a microdeletion on chromosome region 22q11.2. Clinically, it is characterized by congenital anomalies and psychiatric and cognitive manifestations. The most common structural defects are congenital heart disease and palatal anomalies, both due to abnormal development of the pharyngeal pouches. Another less studied manifestation is abdominal wall hernias. Objective: To characterize the frequency and types of hernias in patients with VCFS, and their association with congenital cardiopathies and palatine abnormalities. Patients and Methods: 202 patients were evaluated by direct clinical examination and questionnaire about their phenotypic characteristics. Results were compared to those found in the literature. Results: Age range was 0.5 to 48.4 years old (mean 11.9 years), 50.4 percent were females. Twenty two percent of patients had abdominal wall hernias. Of these, 49.1 percent were inguinal and 40.3 percent, umbilical. Conclusion: Patients with VCFS have a higher incidence of abdominal hernias than general population, described as approximately 5 percent. This is another common manifestation of the syndrome, not attributable to defects in development of pharyngeal pouches and with unknown pathogenesis.

El síndrome velocardiofacial (SVCF) se debe a una microdeleción en la región cromosómica 22q11.2. Clínicamente, se caracteriza por anomalías congénitas y manifestaciones siquiátricas y cognitivas. Entre las malformaciones más comunes, están las cardiopatías congénitas y anomalías palatinas, por defectos en el desarrollo de las bolsas faríngeas. Otra manifestación menos estudiada son las hernias de la pared abdominal. Objetivo: Caracterizar la frecuencia y tipos de hernias en pacientes con SVCF y su asociación con cardiopatías congénitas y anomalías del paladar. Pacientes y Método: Evaluamos 202 pacientes mediante un examen clínico directo y un cuestionario sobre sus características fenotípicas. Comparamos los resultados con la información de la literatura. Resultados: El rango de edad fue de 0,5 a 48,4 años (media de 11,9 años), 50,4 por ciento de sexo femenino. El 22 por ciento de los pacientes presentó hernias de la pared abdominal. De estas, el 49,1 por ciento fueron inguinales y el 40,3 por ciento, umbilicales. La frecuencia de hernias en los pacientes con SVCF es significativamente mayor que la descrita para la población general, aproximadamente un 5 por ciento. Esta es una manifestación común del síndrome, que no es atribuible a defectos del desarrollo de las bolsas faríngeas y cuya patogenia no ha sido definida.

Síndrome de deleção 22q11 e cardiopatias congênitas complexas / 22q11.2 deletion syndrome and complex congenital heart defects

OBJETIVO: Verificar a frequência da síndrome de deleção 22q11 (SD22q11) entre pacientes portadores de cardiopatia congênita do tipo complexa. MÉTODOS: A amostra foi constituída por uma coorte prospectiva e consecutiva de pacientes com cardiopatia complexa em sua primeira hospitalização em uma unidade de tratamento intensivo cardiológica de um hospital pediátrico. Para cada paciente foi preenchida uma ficha de avaliação, com coleta de dados clínicos, e realizado o cariótipo de alta resolução e técnica de hibridização in situ fluorescente (FISH) com pesquisa de microdeleção 22q11. Os defeitos cardíacos foram classificados por um cardiologista participante do estudo. RESULTADOS: A amostra foi composta de 66 pacientes. Quanto à análise cariotípica, alterações foram observadas em cinco pacientes (7,6 por cento); contudo, nenhum deles apresentava deleção 22q11. A avaliação pela técnica de FISH pôde ser realizada com sucesso em 65 pacientes, sendo que a microdeleção 22q11 foi identificada em dois (3,1 por cento). Dos 66 pacientes com defeitos complexos, 52 eram portadores de malformações do tipo conotruncal, sendo que em 51 a pesquisa para microdeleção 22q11 foi realizada. Os dois pacientes portadores da microdeleção 22q11 fizeram parte deste grupo, representando uma frequência de 3,9 por cento. Eles apresentavam tetralogia de Fallot. CONCLUSÃO: A SD22q11 é uma anormalidade frequente entre pacientes com cardiopatias congênitas complexas e conotruncais. Variações da frequência da SD22q11 entre os estudos parecem estar associadas, principalmente, com a forma adotada para a seleção da amostra e às características da população em análise.

OBJECTIVE: Investigate the frequency of 22q11 deletion syndrome among patients with complex congenital heart disease. METHODS: A prospective and consecutive cohort of patients with complex heart defects was evaluated in their first hospitalization at a cardiac intensive care unit of a pediatric hospital. For each patient a protocol of demographic and clinical evaluation was filled. High resolution karyotype and 22q11 microdeletion by fluorescence in situ hybridization was investigated. The heart defects were classified by a cardiologist of the study. RESULTS: The cohort comprised 66 patients. Karyotypic anomalies were observed in 5 patients (7.6 percent), however none of those was the 22q11 deletion. Evaluation by means of FISH was successful in 65 patients and 22q11 microdeletion was identified in 2 (3.1 percent). Of the 66 patients with complex defects, 52 were carriers of conotruncal malformations and in 51 the 22q11 microdeletion analysis by FISH was successful. Both 22q11 microdeletion carriers belonged to this group, representing a frequency of 3.9 percent. They presented tetralogy of Fallot. CONCLUSION: 22q11DS is a frequent abnormality among patients with complex and conotruncal heart defects. Variations of the 22q11DS frequency among studies seem to be mainly associated to criteria for patient selection and specific characteristics of the population in analysis.

DiGeorge Syndrome: a not so rare disease

INTRODUCTION: The DiGeorge Syndrome was first described in 1968 as a primary immunodeficiency resulting from the abnormal development of the third and fourth pharyngeal pouches during embryonic life. It is characterized by hypocalcemia due to hypoparathyroidism, heart defects, and thymic hypoplasia or aplasia. Its incidence is 1:3000 live births and, despite its high frequency, little is known about its natural history and progression. ←This is probably due to diagnostic difficulties and the great variety of names used to describe it, such as velocardiofacial, Shprintzen, DiGeorge, and CATCH 22 Syndromes, as well as conotruncal facial anomaly. All represent the same genetic condition, chromosome 22q11.2 deletion, which might have several clinical expressions. OBJECTIVES: To describe clinical and laboratorial data and phenotypic characteristics of patients with DiGeorge Syndrome. METHODS: Patients underwent standard clinical and epidemiological protocol and tests to detect heart diseases, facial abnormalities, dimorphisms, neurological or behavioral disorders, recurrent infections and other comorbidities. RESULTS: Of 14 patients (8m - 18y11m), only one did not have 22q11.2 deletion detected. The main findings were: conotruncal malformation (n = 12), facial abnormalities (n = 11), hypocalcemia (n = 5) and low lymphocyte count (n=2). CONCLUSION: The authors pointed out the necessity of DGS suspicion in all patient presenting with heart defects, facial abnormalities (associated or not with hypocalcemia), and immunological disorders because although frequency of DGS is high, few patients with a confirmed diagnosis are followed up.

Síndrome de deleção 22q11.2: compreendendo o CATCH22: [revisão] / 22q11.2 deletion syndrome: catching the CATCH22: [review]

OBJETIVO:Realizar uma revisão dos aspectos históricos, epidemiológicos, clínicos, etiológicos e laboratoriais da síndrome de deleção 22q11.2, salientando-se a importância e as dificuldades do seu diagnóstico. FONTES DE DADOS: Pesquisa nas bases de dados Medline, Lilacs e SciELO, além da Internet e capítulos de livros em inglês, acerca de publicações feitas entre 1980 e 2008. Para isso, utilizaram-se os descritores "22q11", "DiGeorge", "Velocardiofacial" e "CATCH22". SÍNTESE DOS DADOS: A síndrome de deleção 22q11.2, também conhecida como síndrome de DiGeorge ou velocardiofacial, foi identificada no começo da década de 1990. A microdeleção 22q11.2 é considerada uma das síndromes de microdeleção genética mais frequentes em seres humanos. Caracteriza-se por um espectro fenotípico bastante amplo, com mais de 180 achados clínicos já descritos do ponto de vista físico e comportamental. Contudo, nenhum achado é patognomônico ou mesmo obrigatório. A maioria dos pacientes apresenta uma deleção pequena, detectada somente por técnicas de genética molecular, como a hibridização in situ fluorescente. Apresenta padrão de herança autossômico dominante, ou seja, indivíduos acometidos apresentam um risco de 50 por cento de transmiti-la a seus filhos. CONCLUSÕES: Pacientes com a síndrome de deleção 22q11.2 frequentemente necessitam, ao longo de suas vidas, de um grande número de intervenções médicas e hospitalizações. O diagnóstico precoce é fundamental para a adequada avaliação e manejo clínico dos indivíduos e seus familiares.

OBJECTIVE:To review historical, epidemiological, clinical, etiological and laboratorial aspects of the 22q11.2 deletion syndrome, highlighting the importance of the diagnosis and its difficulties. DATA SOURCES: MedLine, Lilacs e SciELO databases, as well as internet and book chapters written in English, were searched for the period of 1980-2008, with the following descriptors "22q11", "DiGeorge", "Velocardiofacial" and "CATCH22". DATA SYNTHESIS: 22q11.2 deletion syndrome, also known as DiGeorge or velocardiofacial syndrome, was identified in the beginning of the 1990 decade. The 22q11.2 microdeletion is one of the most common human genetic microdeletion syndromes. It is characterized by a very broad phenotypic spectrum. More than 180 physical and behavioral clinical findings have already been described. However, none of them is characteristic or essential to diagnosis. The majority of the patients present a small deletion only detected by molecular genetic techniques as the fluorescent in situ hybridization. The deletion segregates in the families with an autosomal dominant pattern of inheritance, so the recurrence risk in the families is 50 percent. CONCLUSIONS: Individuals with 22q11.2 deletion syndrome have a great possibility to undergo medical interventions and hospitalizations throughout their lives. Early diagnosis is essential for the evaluation and clinical management of the patients and their families.

VEGFA polymorphisms and cardiovascular anomalies in 22q11 microdeletion syndrome: a case-control and family-based study

Microdeletion 22q11 in humans causes velocardiofacial and DiGeorge syndromes. Most patients share a common 3Mb deletion, but the clinical manifestations are very heterogeneous. Congenital heart disease is present in 50-80 percent of patients and is a significant cause of morbidity and mortality. The phenotypic variability suggests the presence of modifiers. Polymorphisms in the VEGFA gene, coding for the vascular endothelial growth factor A, have been associated with non-syndromic congenital heart disease, as well as with the presence of cardiovascular anomalies in patients with microdeletion 22q11. We evaluated the association of VEGFA polymorphisms c.-2578C>A (rs699947), c.-1154G>A (rs1570360) and c.-634C>G (rs2010963) with congenital heart disease in Chilean patients with microdeletion 22q11. The study was performed using case-control and family-based association designs. We evaluated 122 patients with microdeletion 22q11 and known anatomy of the heart and great vessels, and their parents. Half the patients had congenital heart disease. We obtained no evidence of association by either method of analysis. Our results provide further evidence of the incomplete penetrance of the cardiovascular phenotype of microdeletion 22ql 1, but do not support association between VEGFA promoter polymorphisms and the presence of congenital heart disease in Chilean patients with this syndrome.

Microdeletion study in children with selective congenital heart disease; an Iranian multicenter study

Determining the frequency of chromosome 22q11.2 microdeletion in children with congenital cardiac conotruncal abnormalities using Fluorescence in-situ Hybridization [FISH] technique and estimating relation between DiGeorge Syndrome and cardiac conotruncal abnormalities. One-hundred and eighty cases [106 Males, 74 Females] with selective congenital heart disease [conotruncal abnormalities] referred to the hospitals affiliated to Tehran University during 2004-2007 were evaluated by pediatric cardiologists. All patients were assessed for chromosome 22q11.2 microdeletion using FISH technique. Consequently, patients with 22q microdeletion were studied for T cell abnormalities. Median age of the patients at the time of study was 18 months [3d-16y]. The microdeletion of chromosome 22q11.2 was detected in 17 [9.5%] patients with conotruncal abnormalities, including 5 [29.4%] Tetralogy of Fallot plus Supravalvular Pulmonary Stenosis, 4 [23%] Truncus Arteriosus, 5 [29.4%] Pulmonary Artesia with Ventricular Septal Defect, 2 [11.8%] CO AO+Intrrupted Aortic Arch and one case of Valvular Pulmonary Stenosis. Five of uncorrelated cases had crananiofacial dysmorphism. Chromosome 22q11.2 microdeletion FISH study should be considered in patients with cardiac lesions particularly conotruncal abnormality with or without syndromic problems [craniofacial dysmorphism and developmental delay] to provide an appropriate genetic counseling with more accurate estimation of recurrence risk and ultimately prenatal diagnosis in affected families

Comparing Two Diagnostic Laboratory Tests for Several Microdeletions Causing Mental Retardation Syndromes: Multiplex Ligation-Dependent Amplification vs Fluorescent In Situ Hybridization / 대한진단검사의학회지

BACKGROUND: Microdeletion syndromes not detectable by conventional cytogenetic analysis have been reported to occur in approximately 5% of patients with unexplained mental retardation (MR). Therefore, it is essential to ensure that patients with MR are screened for these microdeletion syndromes. Mental retardation syndrome multiplex ligation-dependent probe amplification (MRS-MLPA) is a new technique for measuring sequence dosages that allows for the detection of copy number changes of several microdeletion syndromes (1p36 deletion syndrome, Williams syndrome, Smith-Magenis syndrome, Miller-Dieker syndrome, DiGeorge syndrome, Prader-Willi/Angelman syndrome, Alagille syndrome, Saethre-Chotzen syndrome, and Sotos syndrome) to be processed simultaneously, thus significantly reducing the amount of laboratory work. METHODS: We assessed the performance of MLPA (MRC-Holland, The Netherlands) for the detection of microdeletion syndromes by comparing the results with those generated using FISH assays. MLPA analysis was carried out on 12 patients with microdeletion confirmed by FISH (three DiGeorge syndrome, four Williams syndrome, four Prader-Willi syndrome, and one Miller-Dieker syndrome). RESULTS: The results of MLPA analysis showed a complete concordance with FISH in 12 patients with microdeletion syndromes. CONCLUSIONS: On the basis of these results, we conclude that MLPA is an accurate, reliable, and cost-effective alternative to FISH in the screening for microdeletion syndromes.

High specificity PCR screening for 22q11.2 microdeletion in three different ethnic groups

Congenital heart defects are the most common of all human birth defects. Numerous studies have shown that a deletion within chromosome 22q11 is associated with DiGeorge syndrome and certain forms of sporadic congenital cardiovascular disease. We have determined the value of a PCR assay using markers D22S941, D22S944 and D22S264 designed for the screening of 22q11.2 deletion through consecutive homozygosity in an ethnically admixed urban population. The study population comprised 149 unrelated men and women from three different ethnic groups (white, mulatto and black). Test specificity for the overall population was estimated at 98.3 percent. We found no significant difference when comparing heterozygosity indices and ethnicity (P value = 0.43 (D22S944), 0.22 (D22S264), and 0.58 (D22S941)). There was no significant difference regarding assay specificity between the three different ethnic groups studied. This assay could constitute a cost-effective way to screen a large number of patients at increased risk, since PCR techniques are easily available, are fast, can be automatized, and are significantly less expensive than fluorescence in situ hybridization

Estudio inmunogenético de un caso de síndrome de DiGeorge / Immunogenetic study of one case in DiGeorge syndrome

El síndrome de DiGeorge es una inmunodeficiencia congénita de rara presentación, clínicamente caracterizado por la tetania hipocalcémica, enfermedad cardiaca congénita, fascies poco común, aumento de la susceptibilidad a la infección. Desde el punto de vista patológico el síndrome de DiGeorge es una forma de alteración en el desarrollo embriológico. Desde el punto de vista genético se ha encontrado pérdida de la porción proximal del brazo largo del cromosona 22. Quienes padecen este síndrome tienen un gran número de alteraciones que pueden cursar con grados variables, lo que ha permitido tres formas de manifestación: completa, parcial y transitoria