Cytogenomic assessment of the diagnosis of 93 patients with developmental delay and multiple congenital abnormalities: The Brazilian experience.

OBJECTIVE: The human genome contains several types of variations, such as copy number variations, that can generate specific clinical abnormalities. Different techniques are used to detect these changes, and obtaining an unequivocal diagnosis is important to understand the physiopathology of the diseases. The objective of this study was to assess the diagnostic capacity of multiplex ligation-dependent probe amplification and array techniques for etiologic diagnosis of syndromic patients. METHODS: We analyzed 93 patients with developmental delay and multiple congenital abnormalities using multiplex ligation-dependent probe amplifications and arrays. RESULTS: Multiplex ligation-dependent probe amplification using different kits revealed several changes in approximately 33.3% of patients. The use of arrays with different platforms showed an approximately 53.75% detection rate for at least one pathogenic change and a 46.25% detection rate for patients with benign changes. A concomitant assessment of the two techniques showed an approximately 97.8% rate of concordance, although the results were not the same in all cases. In contrast with the array results, the MLPA technique detected ∼70.6% of pathogenic changes. CONCLUSION: The obtained results corroborated data reported in the literature, but the overall detection rate was higher than the rates previously reported, due in part to the criteria used to select patients. Although arrays are the most efficient tool for diagnosis, they are not always suitable as a first-line diagnostic approach because of their high cost for large-scale use in developing countries. Thus, clinical and laboratory interactions with skilled technicians are required to target patients for the most effective and beneficial molecular diagnosis.

Cytogenomic assessment of the diagnosis of 93 patients with developmental delay and multiple congenital abnormalities: The Brazilian experience

OBJECTIVE: The human genome contains several types of variations, such as copy number variations, that can generate specific clinical abnormalities. Different techniques are used to detect these changes, and obtaining an unequivocal diagnosis is important to understand the physiopathology of the diseases. The objective of this study was to assess the diagnostic capacity of multiplex ligation-dependent probe amplification and array techniques for etiologic diagnosis of syndromic patients. METHODS: We analyzed 93 patients with developmental delay and multiple congenital abnormalities using multiplex ligation-dependent probe amplifications and arrays. RESULTS: Multiplex ligation-dependent probe amplification using different kits revealed several changes in approximately 33.3% of patients. The use of arrays with different platforms showed an approximately 53.75% detection rate for at least one pathogenic change and a 46.25% detection rate for patients with benign changes. A concomitant assessment of the two techniques showed an approximately 97.8% rate of concordance, although the results were not the same in all cases. In contrast with the array results, the MLPA technique detected ∼70.6% of pathogenic changes. CONCLUSION: The obtained results corroborated data reported in the literature, but the overall detection rate was higher than the rates previously reported, due in part to the criteria used to select patients. Although arrays are the most efficient tool for diagnosis, they are not always suitable as a first-line diagnostic approach because of their high cost for large-scale use in developing countries. Thus, clinical and laboratory interactions with skilled technicians are required to target patients for the most effective and beneficial molecular diagnosis.

Post-mortem cytogenomic investigations in patients with congenital malformations.

Congenital anomalies are the second highest cause of infant deaths, and, in most cases, diagnosis is a challenge. In this study, we characterize patterns of DNA copy number aberrations in different samples of post-mortem tissues from patients with congenital malformations. Twenty-eight patients undergoing autopsy were cytogenomically evaluated using several methods, specifically, Multiplex Ligation-dependent Probe Amplification (MLPA), microsatellite marker analysis with a MiniFiler kit, FISH, a cytogenomic array technique and bidirectional Sanger sequencing, which were performed on samples of different tissues (brain, heart, liver, skin and diaphragm) preserved in RNAlater, in formaldehyde or by paraffin-embedding. The results identified 13 patients with pathogenic copy number variations (CNVs). Of these, eight presented aneuploidies involving chromosomes 13, 18, 21, X and Y (two presented inter- and intra-tissue mosaicism). In addition, other abnormalities were found, including duplication of the TYMS gene (18p11.32); deletion of the CHL1 gene (3p26.3); deletion of the HIC1 gene (17p13.3); and deletion of the TOM1L2 gene (17p11.2). One patient had a pathogenic missense mutation of g.8535C>G (c.746C>G) in exon 7 of the FGFR3 gene consistent with Thanatophoric Dysplasia type I. Cytogenomic techniques were reliable for the analysis of autopsy material and allowed the identification of inter- and intra-tissue mosaicism and a better understanding of the pathogenesis of congenital malformations.

Williams-Beuren Syndrome: A Clinical Study of 55 Brazilian Patients and the Diagnostic Use of MLPA.

Williams-Beuren syndrome (WBS) is a genetic disease caused by a microdeletion in the 7q11.23 region. It is characterized by congenital heart disease, mainly supravalvular aortic stenosis, mental retardation, mild short stature, facial dysmorphisms, and variable abnormalities in different systems. Objectives. To report the clinical findings of 55 Brazilian patients confirmed by multiplex ligation-dependent probe amplification (MLPA). Methods. Patients were followed up for 4 years at the Genetics Unit of the Instituto da Criança of the Hospital das Clínicas, FMUSP, Brazil. A kit specific for WBS was used to detect the 7q11.23 microdeletion. Results. Two patients with negative FISH results had positive MLPA results for WBS. The characteristics of the patients with the deletion were as follows: typical WBS facies (98.2%), neuropsychomotor delay (98.2%), hypersocial behavior (94.5%), hyperacusis (94.5%), and congenital heart disease (81.8%). Conclusions. MLPA was effective in detecting the microdeletion in the 7q11.23 region to confirm the diagnosis of WBS. MLPA was also able to confirm the diagnosis of WBS in two patients with typical clinical characteristics but negative FISH results. Thus, MLPA is a promising method in the diagnostic investigation of WBS. WBS is a multisystemic disorder and therefore requires multidisciplinary care and specific follow-up to prevent complications.

Investigation of Copy Number Variation in Children with Conotruncal Heart Defects / Investigação da Variação no Número de Cópias Gênicas em Crianças com Defeito Cardíaco Conotruncal

Background: Congenital heart defects (CHD) are the most prevalent group of structural abnormalities at birth and one of the main causes of infant morbidity and mortality. Studies have shown a contribution of the copy number variation in the genesis of cardiac malformations. Objectives: Investigate gene copy number variation (CNV) in children with conotruncal heart defect. Methods: Multiplex ligation-dependent probe amplification (MLPA) was performed in 39 patients with conotruncal heart defect. Clinical and laboratory assessments were conducted in all patients. The parents of the probands who presented abnormal findings were also investigated. Results: Gene copy number variation was detected in 7/39 patients: 22q11.2 deletion, 22q11.2 duplication, 15q11.2 duplication, 20p12.2 duplication, 19p deletion, 15q and 8p23.2 duplication with 10p12.31 duplication. The clinical characteristics were consistent with those reported in the literature associated with the encountered microdeletion/microduplication. None of these changes was inherited from the parents. Conclusions: Our results demonstrate that the technique of MLPA is useful in the investigation of microdeletions and microduplications in conotruncal congenital heart defects. Early diagnosis of the copy number variation in patients with congenital heart defect assists in the prevention of morbidity and decreased mortality in these patients. .

Fundamento: Os defeitos cardíacos congênitos são o grupo de anormalidades estruturais mais prevalentes ao nascimento e uma das principais causas de morbidade e mortalidade infantil. Estudos têm mostrado a contribuição da variação no número de cópias na gênese das malformações cardíacas. Objetivos: Investigar a variação no número de cópias gênicas em crianças com defeito cardíaco conotruncal. Métodos: Multiplex Ligation-dependent Probe Amplification (MLPA) foi realizado em 39 pacientes com defeito cardíaco conotruncal. Avaliação clínica e laboratorial foi realizada em todos os pacientes. Os pais dos probandos que apresentaram alterações também foram investigados. Resultados: Variação no número de cópias foi detectada em 7/39 pacientes: deleção 22q11.2, duplicação 22q11.2, duplicação 15q11.2, duplicação 20p12.2, deleção 19p, duplicação 15q e 8p23.2 com duplicação 10p12.31. As características clínicas foram compatíveis com o relatado na literatura associadas com microdeleção/microduplicação encontrada. Nenhuma dessas alterações foi herdada dos pais. Conclusões: Nossos resultados demonstram que a técnica de MLPA é útil na investigação de microdeleções e microduplicações em defeitos cardíacos congênitos conotruncais. O diagnóstico precoce das variações no número de cópias em pacientes com defeito cardíaco congênito auxilia na prevenção de morbidade e diminuição da mortalidade nesses pacientes. .

Investigation of copy number variation in children with conotruncal heart defects.

BACKGROUND: Congenital heart defects (CHD) are the most prevalent group of structural abnormalities at birth and one of the main causes of infant morbidity and mortality. Studies have shown a contribution of the copy number variation in the genesis of cardiac malformations. OBJECTIVES: Investigate gene copy number variation (CNV) in children with conotruncal heart defect. METHODS: Multiplex ligation-dependent probe amplification (MLPA) was performed in 39 patients with conotruncal heart defect. Clinical and laboratory assessments were conducted in all patients. The parents of the probands who presented abnormal findings were also investigated. RESULTS: Gene copy number variation was detected in 7/39 patients: 22q11.2 deletion, 22q11.2 duplication, 15q11.2 duplication, 20p12.2 duplication, 19p deletion, 15q and 8p23.2 duplication with 10p12.31 duplication. The clinical characteristics were consistent with those reported in the literature associated with the encountered microdeletion/microduplication. None of these changes was inherited from the parents. CONCLUSIONS: Our results demonstrate that the technique of MLPA is useful in the investigation of microdeletions and microduplications in conotruncal congenital heart defects. Early diagnosis of the copy number variation in patients with congenital heart defect assists in the prevention of morbidity and decreased mortality in these patients.

Complex structural rearrangement features suggesting chromoanagenesis mechanism in a case of 1p36 deletion syndrome.

Genome rearrangements are caused by the erroneous repair of DNA double-strand breaks, leading to several alterations that result in loss or gain of the structural genomic of a dosage-sensitive genes. However, the mechanisms that promote the complexity of rearrangements of congenital or developmental defects in human disease are unclear. The investigation of complex genomic abnormalities could help to elucidate the mechanisms and causes for the formation and facilitate the understanding of congenital or developmental defects in human disease. We here report one case of a patient with atypical clinical features of the 1p36 syndrome and the use of cytogenomic techniques to characterize the genomic alterations. Analysis by multiplex ligation-dependent probe amplification and array revealed a complex rearrangement in the 1p36.3 region with deletions and duplication interspaced by normal sequences. We also suggest that chromoanagenesis could be a possible mechanism involved in the repair and stabilization of this rearrangement.

Investigação da variação no número de cópias genômicas (CNVs) em pacientes com anomalias congênitas e atraso de desenvolvimento neuropsicomotor (ADNPM) pela técnica de MLPA (Multiplex Ligation-dependent Probe Amplification) / Investigation of the copy number variation (CNVs) in patients with congenital anomalies (CA) and mental retardation (MR) using the MLPA (Multiplex Ligation-dependent Probe Amplification) technique

INTRODUÇÃO: Os desequilíbrios genômicos constituem causa frequente de abortamento, anomalias congênitas (AC) e atraso de desenvolvimento neuropsicomotor (ADNPM). O aprimoramento de novas técnicas de diagnóstico citogenômico, como por exemplo, a MLPA (Multiplex Ligation-dependent Probe Amplification) e a triagem ampla do DNA utilizando arrays, mostraram que a alteração no número normal de cópias genômicas (CNVs) influencia na patogenicidade dos fenótipos em diversas síndromes. OBJETIVOS: Com isso, os objetivos do presente estudo foram identificar CNVs em pacientes com MC e ADNPM utilizando a técnica de MLPA e, a partir dos resultados alterados, aplicar da técnica de array para a identificação de possíveis rearranjos complexos, além de associar as alterações moleculares encontradas com o fenótipo dos pacientes. MÉTODOS: Participaram do estudo 416 pacientes com MC e ADNPM. As amostras de DNA foram analisadas utilizando a técnica de MLPA com kits comerciais para as principais síndromes de microdeleções (P064) e regiões subteloméricas (P036 e P070). Dois kits de MLPA específicos para as regiões 7q11.23 (P029) e 22q11.2 (P250) também foram utilizados para complementar a identificação de CNVs atípicas. Entre os casos que apresentavam alterações pela técnica de MLPA, 15 pacientes foram submetidos à técnica de array, utilizando três diferentes plataformas: Agilent SurePrint G3 Genoma Humano microarray 180 K, HumanCytoSNP-12 BeadChip, CytoScan(TM) HD array 6.0 Affymetrix®. RESULTADOS: A análise molecular pela técnica de MLPA possibilitou a detecção de microdeleções e/ou microduplicações em 97 pacientes sendo que: em 46 pacientes foi possível encontrar alterações utilizando apenas o kit P064 (microdeleções), em 34 pacientes utilizando apenas os kits P036 e P070 (regiões subteloméricas) e em quatro pacientes só foi possível identificar a alteração utilizando outro kit de MLPA (P250), específico para alterações genômicas em 22q11.2. Rearranjos complexos, envolvendo mais...

INTRODUCTION: Genomic imbalances are the most common cause of miscarriage, congenital anomalies (CA) and mental retardation (MR). With the improvement of new cytogenomics diagnostic techniques, such as the MLPA (Multiplex Ligation-dependent Probe Amplification) and the array techniques, it have been shown that changes in the normal gene copy number influence the pathogenic variability of phenotypes in different syndromes. AIMS: The aims of the present study were to identify CNVs in patients with CM and RM using the MLPA technique and, from the abnormalities results, to apply the array methodology for the identification of complex rearrangements. Furthermore, the study aimed to associate the alterations found by molecular techniques with the phenotype of patients. METHODS: 416 patients with CM and RM participated in the study. The samples were analysed by MLPA technique with commercial kits for the main microdeletion syndromes (P064) and subtelomeric regions (P036 and P070). Two more MLPA kits for specific regions 7q11.23 (P029) and 22q11.2 (P250) were used to confirm the altered results and to complement some results with the identification of atypical abnormalities. From the patients who presented abnormalities by MLPA technique, 15 underwent by microarray-based comparative genomic hybridization (CGH-array) technique, using three different platform: Agilent SurePrint G3 Human Genome microarray 180 kb, HumanCytoSNP -12 BeadChip, CytoScan(TM) HD ® and Affymetrix 6.0. RESULTS: The molecular analysis by MLPA technique allowed the detection of microdeletions and/or microduplications in 97 patients. In 46 patients it was possible to find genomic alteration using only MLPA kit P064 and in 34 patients using only the subtelomeric kits P036 and P070. For four patients it was only possible to identify the genomic abnormalities using another specific MLPA kit (P250), involving the 22q11.2 region. Complex rearrangements involving more than three chromosomes were detected...

Estresse em crianças e adolescentes com Síndrome de Williams-Beuren em idade escolar / Stress in children and adolescents with Williams-Beuren syndrome in school age / Estrés en niños y adolescentes con síndrome de Williams-Beuren en edad escolar

Síndrome de Williams-Beuren é uma doença de múltiplos órgãos causada por microdeleção de 25 genes no cromossomo 7 (q11.23), sugerindo uma vulnerabilidade ao estresse. Objetivamos determinar se crianças e adolescentes com síndrome de Williams-Beuren apresentam níveis elevados de estresse. Avaliamos 40 indivíduos em idade escolar, com diagnóstico de síndrome de Williams-Beuren e grupo controle. Os instrumentos utilizados: Escala de Estresse Infantil (ESI), Escala de Inteligência para Crianças (WISC), Escala de Inteligência para Adultos (WAIS) e um questionário semiestruturado. No grupo com o SWB, 50% tinham altos níveis de estresse em comparação com 28,6% no grupo controle, diferença altamente significativa estatisticamente (p <0,001). De escola de inclusão, 40,7% apresentaram maior estresse; de escola especial, 69,2% (p> 0,140). Indivíduos com síndrome de Williams mostram índice elevado de estresse. Este estudo destaca a necessidade de orientação sobre a síndrome a pais e gestão escolar, com foco na redução de possíveis fatores ambientais estressantes.(AU)

Williams-Beuren syndrome is a multiorgan disease caused by microdeletion of 25 genes on chromosome 7 (q11.23), suggesting a vulnerability to stress. In this study we aim to determine whether children and adolescents with Williams-Beuren syndrome have high levels of stress. We studied 40 subjects of school age, with confirmed diagnosis of Williams-Beuren syndrome and control group. The instruments used: Child Stress Scale (ESI), Intelligence Scale for Children (WISC), Adult Intelligence Scale (WAIS), and a questionnaire semi-estructured. In the group with SWB, 50% had high levels of stress compared with 28.6% in the control group, statistically highly significant difference (p <0.001). In Inclusion school, 40.7% revealed higher stress; special school 69.2% (p> 0,140) difference was not statistically significant. Individuals with Williams syndrome show high level of stress. This study highlights the need for guidance about the syndrome to parents and school management, with focus on reducing of possible environmental stressors factors.(AU)

El Síndrome de Williams-Beuren es una enfermedad de múltiplos órganos causada por microdeleción de 25 genes en el cromosoma 7 (q11.23) sugiriendo una vulnerabilidad al estrés. El objetivo del estudio fue determinar si niños y adolescentes con síndrome de Williams-Beuren presentan niveles elevados de estrés. Evaluamos 40 individuos en edad escolar con diagnóstico de síndrome de Williams-Beuren y grupo control. Los instrumentos utilizados: Escala de Estrés Infantil (ESI), Escala de Inteligencia para niños (WISC), Escala de Inteligencia para Adultos (WAIS) y un cuestionario semi-estructurado. En el grupo con el SWB 50% tenían altos niveles de estrés en comparación con 28,6% en el grupo control, diferencia altamente significativa estadísticamente (p <0,001). De la escuela de inclusión 40,7% presentaron mayor estrés; de la escuela especial 69,2% (p> 0,140). Individuos con Síndrome de Williams muestran índice elevado de estrés. Este estudio destaca la necesidad de orientación sobre el síndrome a padres y gestión escolar con enfoque en la reducción de posibles factores ambientales estresantes.(AU)

Estresse em crianças e adolescentes com Síndrome de Williams-Beuren em idade escolar / Stress in children and adolescents with Williams-Beuren syndrome in school age / Estrés en niños y adolescentes con síndrome de Williams-Beuren en edad escolar

Síndrome de Williams-Beuren é uma doença de múltiplos órgãos causada por microdeleção de 25 genes no cromossomo 7 (q11.23), sugerindo uma vulnerabilidade ao estresse. Objetivamos determinar se crianças e adolescentes com síndrome de Williams-Beuren apresentam níveis elevados de estresse. Avaliamos 40 indivíduos em idade escolar, com diagnóstico de síndrome de Williams-Beuren e grupo controle. Os instrumentos utilizados: Escala de Estresse Infantil (ESI), Escala de Inteligência para Crianças (WISC), Escala de Inteligência para Adultos (WAIS) e um questionário semiestruturado. No grupo com o SWB, 50% tinham altos níveis de estresse em comparação com 28,6% no grupo controle, diferença altamente significativa estatisticamente (p <0,001). De escola de inclusão, 40,7% apresentaram maior estresse; de escola especial, 69,2% (p> 0,140). Indivíduos com síndrome de Williams mostram índice elevado de estresse. Este estudo destaca a necessidade de orientação sobre a síndrome a pais e gestão escolar, com foco na redução de possíveis fatores ambientais estressantes.

Williams-Beuren syndrome is a multiorgan disease caused by microdeletion of 25 genes on chromosome 7 (q11.23), suggesting a vulnerability to stress. In this study we aim to determine whether children and adolescents with Williams-Beuren syndrome have high levels of stress. We studied 40 subjects of school age, with confirmed diagnosis of Williams-Beuren syndrome and control group. The instruments used: Child Stress Scale (ESI), Intelligence Scale for Children (WISC), Adult Intelligence Scale (WAIS), and a questionnaire semi-estructured. In the group with SWB, 50% had high levels of stress compared with 28.6% in the control group, statistically highly significant difference (p <0.001). In Inclusion school, 40.7% revealed higher stress; special school 69.2% (p> 0,140) difference was not statistically significant. Individuals with Williams syndrome show high level of stress. This study highlights the need for guidance about the syndrome to parents and school management, with focus on reducing of possible environmental stressors factors.

El Síndrome de Williams-Beuren es una enfermedad de múltiplos órganos causada por microdeleción de 25 genes en el cromosoma 7 (q11.23) sugiriendo una vulnerabilidad al estrés. El objetivo del estudio fue determinar si niños y adolescentes con síndrome de Williams-Beuren presentan niveles elevados de estrés. Evaluamos 40 individuos en edad escolar con diagnóstico de síndrome de Williams-Beuren y grupo control. Los instrumentos utilizados: Escala de Estrés Infantil (ESI), Escala de Inteligencia para niños (WISC), Escala de Inteligencia para Adultos (WAIS) y un cuestionario semi-estructurado. En el grupo con el SWB 50% tenían altos niveles de estrés en comparación con 28,6% en el grupo control, diferencia altamente significativa estadísticamente (p <0,001). De la escuela de inclusión 40,7% presentaron mayor estrés; de la escuela especial 69,2% (p> 0,140). Individuos con Síndrome de Williams muestran índice elevado de estrés. Este estudio destaca la necesidad de orientación sobre el síndrome a padres y gestión escolar con enfoque en la reducción de posibles factores ambientales estresantes.

FGFR4 profile as a prognostic marker in squamous cell carcinoma of the mouth and oropharynx.

BACKGROUND: Fibroblast growth factor receptor 4 (FGFR4) is a member of a receptor tyrosine kinase family of enzymes involved in cell cycle control and proliferation. A common single nucleotide polymorphism (SNP) Gly388Arg variant has been associated with increased tumor cell motility and progression of breast cancer, head and neck cancer and soft tissue sarcomas. The present study evaluated the prognostic significance of FGFR4 in oral and oropharynx carcinomas, finding an association of FGFR4 expression and Gly388Arg genotype with tumor onset and prognosis. PATIENTS AND METHODS: DNA from peripheral blood of 122 patients with oral and oropharyngeal squamous cell carcinomas was used to determine FGFR4 genotype by PCR-RFLP. Protein expression was assessed by immunohistochemistry (IHC) on paraffin-embedded tissue microarrays. RESULTS: Presence of allele Arg388 was associated with lymphatic embolization and with disease related premature death. In addition, FGFR4 low expression was related with lymph node positivity and premature relapse of disease, as well as disease related death. CONCLUSION: Our results propose FGFR4 profile, measured by the Gly388Arg genotype and expression, as a novel marker of prognosis in squamous cell carcinoma of the mouth and oropharynx.

Detection of deletions at 7q11.23 in Williams-Beuren syndrome by polymorphic markers.

INTRODUCTION: Williams-Beuren syndrome (WBS; OMIM 194050) is caused by a hemizygous contiguous gene microdeletion at 7q11.23. Supravalvular aortic stenosis, mental retardation, overfriendliness, and ocular and renal abnormalities comprise typical symptoms in WBS. Although fluorescence in situ hybridization is widely used for diagnostic confirmation, microsatellite DNA markers are considered highly informative and easily manageable. OBJECTIVES: This study aimed to test the microsatellite markers for the diagnosis of Williams-Beuren syndrome, to determine the size and parental origin of microdeletion, compare the clinical characteristics between patients with different sizes of the deletion and parental origin. METHODS: We studied 97 patients with clinical diagnosis of Williams-Beuren syndrome using five microsatellite markers: D7S1870, D7S489, D7S613, D7S2476 and D7S489_A. RESULTS AND DISCUSSION: Using five markers together, the result was informative in all patients. The most informative marker was D7S1870 (78.4%), followed by D7S613 (75.3%), D7S489 (70.1%) and D7S2476 (62.9%). The microdeletion was present in 84 (86.6%) patients and absent in 13 (13.4%) patients. Maternal deletions were found in 52.4% of patients and paternal deletions in 47.6% of patients. The observed size of deletions was 1.55 Mb in 76/ 84 patients (90.5%) and 1.84 Mb in 8/84 patients (9.5%). SVAS as well as ocular and urinary abnormalities were more frequent in the patients with a deletion. There were no clinical differences in relation to either the size or parental origin of the deletion. CONCLUSION: Using these five selected microsatellite markers was informative in all patients, thus can be considered an alternative method for molecular diagnosis in Williams-Beuren syndrome.

Detection of deletions at 7q11.23 in Williams-Beuren syndrome by polymorphic markers

INTRODUCTION: Williams-Beuren syndrome (WBS; OMIM 194050) is caused by a hemizygous contiguous gene microdeletion at 7q11.23. Supravalvular aortic stenosis, mental retardation, overfriendliness, and ocular and renal abnormalities comprise typical symptoms in WBS. Although fluorescence in situ hybridization is widely used for diagnostic confirmation, microsatellite DNA markers are considered highly informative and easily manageable. OBJECTIVES: This study aimed to test the microsatellite markers for the diagnosis of Williams-Beuren syndrome, to determine the size and parental origin of microdeletion, compare the clinical characteristics between patients with different sizes of the deletion and parental origin. METHODS: We studied 97 patients with clinical diagnosis of Williams-Beuren syndrome using five microsatellite markers: D7S1870, D7S489, D7S613, D7S2476 and D7S489_A. RESULTS AND DISCUSSION: Using five markers together, the result was informative in all patients. The most informative marker was D7S1870 (78.4 percent), followed by D7S613 (75.3 percent), D7S489 (70.1 percent) and D7S2476 (62.9 percent). The microdeletion was present in 84 (86.6 percent) patients and absent in 13 (13.4 percent) patients. Maternal deletions were found in 52.4 percent of patients and paternal deletions in 47.6 percent of patients. The observed size of deletions was 1.55 Mb in 76/ 84 patients (90.5 percent) and 1.84 Mb in 8/84 patients (9.5 percent). SVAS as well as ocular and urinary abnormalities were more frequent in the patients with a deletion. There were no clinical differences in relation to either the size or parental origin of the deletion. CONCLUSION: Using these five selected microsatellite markers was informative in all patients, thus can be considered an alternative method for molecular diagnosis in Williams-Beuren syndrome.

High frequency of autistic traits in Williams-Beuren patients / Alta frequência dos traços de autismo em pacientes com síndrome de Williams-Beuren

Williams-Beuren syndrome is characterized by typical facies, supravalvular aortic stenosis, mental retardation, hyperacusis, and behavioral abnormalities with overfriendly personality and anxiety disorders. It is caused by a microdeletion of contiguous genes located in the 7q11.23 region. We studied 31 patients with the Williams-Beuren syndrome (19 men and 12 women), whose ages ranged from 9 to 26 years-old (median 14 years-old). The Williams-Beuren syndrome diagnosis was confirmed by FISH or microsatellite markers analysis in all patients. The objectives were to evaluate cognitive ability, verbal and total intelligence quotient execution, frequency of visual-spatial deficits, and autistic traits and to compare the results of molecular findings. The tests used were the WISC-III, WAIS-III, Rey Complex Figure and a scale of autistic traits. Their total intelligence quotient scores ranged from 51 to 86 (median of 63): 22 with mild mental retardation, 4 with moderate retardation, 4 classified as borderline and 1 as below average. All patients had marked visual-spatial deficit. The frequency of autistic traits was found in 13 of 31 patients (41.94%), with a predominance in males (ten men and three women). There was no correlation with the incidence of autistic traits in relation to the size of the deletion. This study reinforces the importance of the systematic assessment of cognitive function in Williams-Beuren syndrome patients, and it alerts researchers to the presence of a high frequency of autistic traits, as opposed to the overfriendly personality traits, which is typically showed by Williams-Beuren syndrome patients. These latter data are preliminary and further studies are necessary to confirm this specific finding in Williams-Beuren syndrome patients.

A síndrome de Williams-Beuren é caracterizada por fácies típicos, estenose aórtica supravalvar, retardo mental, hiperacusia e anormalidades comportamentais com personalidade amigável e distúrbios de ansiedade. É causada por microdeleção de genes contíguos localizados na região 7q11.23. Foram estudados 31 pacientes com a síndrome de Williams-Beuren (19 homens e 12 mulheres), cujas idades variaram de 9 a 26 anos (mediana de 14 anos). O diagnóstico da síndrome de Williams-Beuren foi confirmado pelo FISH (Fluorescence In Situ Hibridisation) ou por análise de marcadores microssatélites em todos os pacientes. Os objetivos foram: avaliar a capacidade cognitiva, o quociente de inteligência de execução verbal e total, a frequência de déficits visoespaciais, traços autistas; e comparar os resultados dos achados moleculares. Os testes utilizados foram: WISC-III, WAIS-III, Figuras Complexas de Rey e Escala de Traços Autísticos. Os pacientes apresentaram déficit cognitivo em todos os testes, o quociente de inteligência total variou de 51 a 86 (mediana de 63): 22 com deficiência mental leve, 4 com deficiência mental moderada; 4 limítrofes e 1 com média inferior. Os pacientes apresentaram déficit visoespacial. A frequência de traços autistas foi encontrada em 13 dos 31 pacientes (41,94%), com predomínio no sexo masculino (dez homens e três mulheres). Não foi encontrada correlação entre a presença de traços autísticos em relação ao tamanho da deleção. O presente estudo reforça a importância da avaliação sistemática da função cognitiva em pacientes com a síndrome de Williams-Beuren e alerta para a presença da alta frequência de traços autistas, que é o oposto da personalidade amigável tipicamente encontrada em pacientes com síndrome de Williams-Beuren. Estes últimos dados são preliminares e novos estudos serão necessários para confirmar este achado específico na síndrome de Williams-Beuren.