Identification of a mosaic non-inherited small supernumerary ring chromosome 2: cytogenetic-molecular studies and genotype-phenotype correlation

Introduction: The identification of supernumerary marker chromosomes (SMCs) derived from all the autosomes is currently possible, but rarely by conventional cytogenetics alone. Supernumerary ring chromosomes (SRCs) account for about 10% of these cases. SRCs derived from chromosome 2 are unusual, and there are only a few cases reported in the literature. The severity of the phenotype depends on the type of the mosaicism, the percentage of cells affected by the genetic change and the chromosome involved. Methods: The authors report the case of a boy aged 8 referred for cytogenetic studies, presenting with behavior and learning problems, mental retardation with uncoordenated speech, attention deficit and hyperactivity (PHDA), as well as small slanting palpebral fissures. The karyotype was obtained from peripheral blood lymphocyte cultures using high resolution GTL banding and standard techniques. Fluorescence in situ hybridization (FISH) was performed using specific probes for the centromeric regions of all chromosomes (Chromoprobe Multiprobe - ISystem). Results: Cytogenetic analysis revealed two cell lines: one with a supernumerary marker ring chromosome, 47,XY,+r (52%), and a normal cell line, 46,XY (48%). The SRC was identified by FISH with the chromosome 2 centromeric probe. Since the parents had normal karyotypes, this abnormality was “de novo”. Final karyotype of the proband was: mos 47,XY,+r[26]/46,XY[24].ish r(2)(D2Z2+)dn. Discussion: The clinical description of this patient is in agreement with other reports of the literature. Molecular characterization by FISH analyses is an useful way of investigating the presence of euchromatin contained in a SMC and establishing new chromosomal syndromes. However, to better characterize this ring, in order to establish a more accurate genotype-phenotype correlation, more studies involving other technologies should be performed, thus allowing suitable genetic counsellin

Deleção cromossómica intersticial em 14q “de novo”: apresentação de um caso

Introdução: As deleções intersticiais são anomalias cromossómicas estruturais, desequilibradas, resultantes de dois pontos de quebra, frequentemente associadas a quadros clínicos anormais devido à perda de material genético ativo (eucromatina). As consequências fenotípicas dependem do segmento cromossómico perdido e do número de genes aí localizados. Material e Métodos: Os autores apresentam o caso de um indivíduo do sexo masculino, de 11 anos de idade, referenciado para estudo citogenético por apresentar um quadro clínico de atraso de desenvolvimento psicomotor, défice cognitivo e problemas de comportamento. Realizaram-se culturas sincronizadas de linfócitos de sangue periférico, bandas GTG de alta resolução e, posteriormente, estudos de hibridação in situ por fluorescência (FISH) com sondas de pintura cromossómica total e subtelomérica, específicas para o cromossoma 14. Resultados: A análise das metafases revelou a presença de uma anomalia estrutural no cromossoma 14, interpretada como uma deleção intersticial do segmento compreendido entre as bandas 14q24.3 e 14q32.1. A análise por FISH permitiu confirmar esta deleção intersticial. Como os cariótipos dos pais foram normais, conclui-se que esta anomalia cromossómica é “de novo”, estabelecendo-se o cariótipo do doente como: 46,XY,del(14)(q24.3q32.1).ish del(14)(wcp 14+,SHGC36156+)dn Discussão: A deleção intersticial encontrada no cromossoma 14 implica uma monossomia do segmento 14q24.3→14q32.1. As alterações descritas mais comuns, associadas a esta deleção, incluem ADPM e algumas malformações minor. Os autores apresentam este caso pela raridade da anomalia citogenética encontrada e comparam-no com a literatura atual

Diagnóstico Pré-natal de Síndrome de Wolf-Hirschhorn: a propósito de um caso

Introdução: O Síndrome de Wolf-Hirschhorn é uma patologia originada por uma deleção da região terminal do braço curto do cromossoma 4. O tamanho da deleção pode ser variável levando a um espectro alargado de manifestações clínicas. Em diagnóstico pré-natal (DPN), as alterações fetais mais frequentes incluem atraso do crescimento intra-uterino, lábio leporino e/ou fenda do palato e anomalias cardíacas. A prevalência estimada é de 1/50.000 nascimentos afetando duas vezes mais indivíduos do sexo feminino do que do sexo masculino. Objectivo: Apresentação de um caso de Síndrome de Wolf-Hirschhorn em DPN comparando-o com outros casos publicados. Material e métodos: Grávida com 17semanas de gestação, referenciada para estudos cromossómicos por idade materna avançada (35 anos) e rastreio bioquímico positivo para trissomia 18. A análise citogenética convencional dos amniócitos cultivados foi realizada de acordo com os métodos habituais usando bandas GTG. O estudo foi complementado por técnicas de citogenética molecular (FISH) utilizando-se a sonda específica para a região do Síndrome de Wolf-Hirschhorn. Resultados: O estudo cromossómico efetuado, revelou uma deleção na região terminal do braço curto do cromossoma 4. A análise por FISH confirmou a existência da deleção desta região, permitindo estabelecer o cariótipo 46,XX,del(4)(p15.3).ish del(4)(p16.3p16.3)(WCHR-). Os cariótipos efetuados aos pais foram normais. Conclusões: Discute-se a importância deste caso pela raridade da anomalia citogenética encontrada, assim como pela dificuldade em realizar o diagnóstico por citogenética convencional, em alguns destes casos, quando não se obtêm bandas de alta resolução

Clinical, cytogenetic and molecular findings of a “de novo” inv dup del (6q)

Introduction: Complex rearrangements resulting in inverted duplications contiguous to a terminal deletion (inv dup del) were first reported for the short arm of chromosome 8 in1976. Since then this type of structural anomaly has been described for an increasing number of chromosomes. In these rearrangements, the concomitant presence of a deletion and a duplication has important consequences in genotype-phenotype correlations. The authors describe the clinical findings and the cytogenetic characterization of a rare inv dup del involving the long arm of chromosome 6. Material and methods: A girl aged 5 was referred for subtelomeric studies with the indication of psychomotor retardation, autistic features and stereotipies. Chromosome analysis with high resolution GTL-banding was performed on metaphases obtained from cultured peripheral blood lymphocytes. Molecular studies included MLPA (Kits P036 and P070, MRC-Holland), FISH with subtelomeric and whole chromosome painting probes specific for chromosome 6, and cCGH techniques. Results: Initial MLPA studies detected a subtelomeric deletion in the long arm of chromosome 6; the subsequent karyotype revealed a structurally abnormal chromosome 6 with additional material in the end of the long arm. FISH analysis showed the deletion and demonstrated that the extra material was derived from chromosome 6; cCGH tecnhiques defined the extension and confirmed the breakpoints of the duplicated segment. Thus this rearrangement was interpreted as an inv dup del (6q). Since parental karyotypes were normal, this anomaly was considered “de novo”. Discussion: As far as we know this is the first description of a patient presenting with a “de novo” inv dup del (6q). We compare the clinical features in this child with the previously reported cases with either an isolated terminal deletion or a duplication of distal 6q. The authors enhance the importance of the combination of high resolution banding with molecular studies in the characterization of this rare rearrangement

Interstitial deletion 15q21 and Prader-Willi like syndrome phenotype: Case report

Introduction: Chromosome 15q interstitial deletions not involving the Prader-Willi/Angelman region are uncommon and poorly characterized. Very few cases of different segmental losses involving the 15q21 region have been reported at cytogenetic level. All the described patients present with moderate to several mental retardation and characteristic facial dysmorphic features. Some authors compare the similarity between the phenotype of these patients with some features of Prader-Willi syndrome (PWS). Methods: We report the case of a girl aged 8 referred for conventional cytogenetics and fluorescence in situ hybridization (FISH) for the PWS region, presenting with mental retardation, almond-shaped eyes, obesity, small hands with short fingers and diminished pigmentation of the hair. Results: The chromosomal analysis revealed an interstitial deletion of the long arm of chromosome 15, apparently between 15q21 and 15q22. Deletion at 15q11.2 (Prader-Willi/Angelman critical region) was excluded by FISH. To establish the exact breakpoints molecular studies were performed using bacterial artificial chromosome (BAC) clones spanning the 15q21.3 region. The absence of signal in this region defines the proband’s final karyotype as: 46,XX,del(15)(q21.3q21.3).ish del(15)(q21.3q21.3)(bA74K1-) Discussion: The authors emphasize the importance of complementary FISH and molecular studies in chromosomal abnormalities and compare the proband’s phenotype with similar cases described in the literature

Diagnóstico Citogenético em Líquidos Amnióticos Realizado entre 2000-2011 no Centro de Genética Médica Jacinto Magalhães, INSA, IP

Introdução: O diagnóstico pré-natal citogenético efetuado em líquido amniótico é um método seguro e fiável para deteção de anomalias cromossómicas fetais, sendo habitualmente realizado a partir das 15 semanas de gestação. Obtêm-se resultados, em média, após 8-10 dias de cultura dos amniócitos. Objectivo: Apresentar a estatística dos resultados obtidos na análise citogenética de líquidos amnióticos realizada na Unidade de Citogenética do Centro de Genética Médica Jacinto Magalhães entre 2000 e 2011, comparando-os com o descrito na literatura. Material e métodos: Entre janeiro de 2000 e dezembro de 2011 foram processados 10149 líquidos amnióticos. Os motivos para a realização da amniocentese foram, nomeadamente, idade materna avançada, anomalias ecográficas, marcadores ecográficos, rastreio bioquímico positivo, familiares com anomalias cromossómicas e risco de doença monogénica. Foram realizadas culturas de amniócitos de acordo com as técnicas convencionais de citogenética e os cromossomas identificados com bandas GTG ou GTL. Sempre que necessário efetuaram-se estudos de citogenética molecular (FISH) com as sondas adequadas ao esclarecimento do caso. Resultados: A análise revelou 342 cariótipos anormais (3,4%) dos quais 234 tinham anomalias numéricas e 108 estruturais. Os Síndromes de Down, de Edwards e de Turner foram as anomalias mais frequentes. Vinte e três culturas não cresceram, representando uma percentagem de 0,2% de insucesso. Conclusões: Os autores correlacionam os resultados obtidos com as indicações clínicas fornecidas e comparam-nas com o descrito na literatura. O presente estudo poderá ser utilizado para o estabelecimento de uma base de dados a nível nacional

Guess what: Chronic 13q14.3+/CD5‐ /CD23+ lymphocytic leukemia in blood and t(11;14)(q13;q32)+/CD5+/CD23‐ mantle cell lymphoma in lymph nodes!

Cytometry B Clin Cytom. 2003 Jan;51(1):41-4. Guess what: Chronic 13q14.3+/CD5-/CD23+ lymphocytic leukemia in blood and t(11;14)(q13;q32)+/CD5+/CD23- mantle cell lymphoma in lymph nodes! Lima M, Pinto L, Dos Anjos Teixeira M, Canelhas A, Mota A, Cabeda JM, Silva C, Queirós ML, Fonseca S, Santos AH, Brochado P, Justiça B. Service of Clinical Hematology, Hospital Geral de Santo António, Porto, Portugal. [email protected] Abstract We report a case of a patient with two B-cell lymphoproliferative disorders: CD5(-)/CD23(+) B-cell chronic lymphocytic leukemia and CD5(+)/CD23(-) mantle cell lymphoma. These disorders were diagnosed simultaneously based on flow cytometry, immunohistochemistry, fluorescence in situ hybridization, and polymerase chain reaction-based molecular studies. The B-cell lymphocytic leukemia clone predominated in the blood and bone marrow, whereas the mantle cell clone predominated in lymph nodes. Copyright 2002 Wiley-Liss, Inc. PMID: 12500296 [PubMed - indexed for MEDLINE

Lipase mediated enzymatic kinetic resolution of phenylethyl halohydrins acetates: A case of study and rationalization

Racemic phenylethyl halohydrins acetates containing several groups attached to the aromatic ring were resolved via hydrolysis reaction in the presence of lipase B from Candida antarctica (Novozym\uae 435). In all cases, the kinetic resolution was highly selective (E > 200) leading to the corresponding (S)-\u3b2-halohydrin with ee > 99 %. However, the time required for an ideal 50 % conversion ranged from 15 min for 2,4-dichlorophenyl chlorohydrin acetate to 216 h for 2-chlorophenyl bromohydrin acetate. Six chlorohydrins and five bromohydrins were evaluated, the latter being less reactive. For the \u3b2-brominated substrates, steric hindrance on the aromatic ring played a crucial role, which was not observed for the \u3b2-chlorinated derivatives. To shed light on the different reaction rates, docking studies were carried out with all the substrates using MD simulations. The computational data obtained for the \u3b2-brominated substrates, based on the parameters analysed such as NAC (near attack conformation), distance between Ser-O and carbonyl-C and oxyanion site stabilization were in agreement with the experimental results. On the other hand, the data obtained for \u3b2-chlorinated substrates suggested that physical aspects such as high hydrophobicity or induced change in the conformation of the enzymatic active site are more relevant aspects when compared to steric hindrance effects

Diagnostic and therapeutic approach to cardioinhibitory reflex syncopeA complex and controversial issue

Syncope is defined as a transient loss of consciousness due to global cerebral hypoperfusion and is one of the leading causes of emergency department admission. The initial approach should focus on excluding non‐syncopal causes for loss of consciousness and risk stratification for cardiac cause, in order to ensure an appropriate etiological investigation and therapeutic approach. Vasovagal syncope (VVS), the most common type of syncope, should be assumed once other causes are excluded. Pathophysiologically, the vasovagal reflex is the result of a paradoxical autonomic response, leading to hypotension and/or bradycardia. VVS has not been shown to affect mortality, but morbidity may be considerable in those with recurrent syncopal episodes. The management of VVS includes both non‐pharmacological and pharmacological measures that act on various levels of the reflex arc that triggers the syncopal episode. However, most are of uncertain benefit given the scarcity of high‐quality supporting evidence. Pacemaker therapy may be considered in recurrent refractory cardioinhibitory reflex syncope, for which it is currently considered a robust intervention, as noted in the European guidelines. Non‐randomized and unblinded studies have shown a potential benefit of pacing in recurrent VVS, but double‐blinded randomized controlled trials have not consistently demonstrated positive results. We performed a comprehensive review of the current literature and recent advances in cardiac pacing and pacing algorithms in VVS, and discuss the diagnostic and therapeutic approach to the complex patient with recurrent VVS and reduced quality of life.publishersversionpublishe