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Browsing by Author "Soares, G."

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  • Clinical, cytogenetic and molecular findings of a “de novo” inv dup del (6q)
    Publication . Fonseca Silva, M.L.; Mota Freitas, M.; Candeias, C.; Ribeiro, J.; Oliva Teles, N.; Soares, G.; Tkachenko, N.; Marques, B.; Correia, H.
    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.
    2012-11-22Conference object Open access Show more
  • Diagnóstico Pré-natal de Síndrome de Wolf-Hirschhorn: a propósito de um caso
    Publication . Candeias, C.; Mota Freitas, M.; Ribeiro, J.; Oliva Teles, N.; Correia, H.; Soares, G.; Nogueira, R.; Fonseca Silva, M.L.
    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.
    2012-09-28Conference object Open access Show more
  • Phenotype and genotype in 101 males with X-linked creatine transporter deficiency
    Publication . van de Kamp, J.M.; Betsalel, O.T.; Mercimek-Mahmutoglu, S.; Abulhoul, L.; Grünewald, S.; Anselm, I.; Azzouz, H.; Bratkovic, D.; de Brouwer, A.; Hamel, B.; Kleefstra, T.; Yntema, H.; Campistol, J.; Vilaseca, M.A.; Cheillan, D.; D'Hooghe, M.; Diogo, L.; Garcia, P.; Valongo, C.; Fonseca, M.; Frints, S.; Wilcken, B.; von der Haar, S.; Meijers-Heijboer, H.E.; Hofstede, F.; Johnson, D.; Kant, S.G.; Lion-Francois, L.; Pitelet, G.; Longo, N.; Maat-Kievit, J.A.; Monteiro, J.P.; Munnich, A.; Muntau, A.C.; Nassogne, M.C.; Osaka, H.; Ounap, K.; Pinard, J.M.; Quijano-Roy, S.; Poggenburg, I.; Poplawski, N.; Abdul-Rahman, O.; Ribes, A.; Arias, A.; Yaplito-Lee, J.; Schulze, A.; Schwartz, C.E.; Schwenger, S.; Soares, G.; Sznajer, Y.; Valayannopoulos, V.; Van Esch, H.; Waltz, S.; Wamelink, M.M.; Pouwels, P.J.; Errami, A.; van der Knaap, M.S.; Jakobs, C.; Mancini, G.M.; Salomons, G.S.
    BACKGROUND: Creatine transporter deficiency is a monogenic cause of X-linked intellectual disability. Since its first description in 2001 several case reports have been published but an overview of phenotype, genotype and phenotype--genotype correlation has been lacking. METHODS: We performed a retrospective study of clinical, biochemical and molecular genetic data of 101 males with X-linked creatine transporter deficiency from 85 families with a pathogenic mutation in the creatine transporter gene (SLC6A8). RESULTS AND CONCLUSIONS: Most patients developed moderate to severe intellectual disability; mild intellectual disability was rare in adult patients. Speech language development was especially delayed but almost a third of the patients were able to speak in sentences. Besides behavioural problems and seizures, mild to moderate motor dysfunction, including extrapyramidal movement abnormalities, and gastrointestinal problems were frequent clinical features. Urinary creatine to creatinine ratio proved to be a reliable screening method besides MR spectroscopy, molecular genetic testing and creatine uptake studies, allowing definition of diagnostic guidelines. A third of patients had a de novo mutation in the SLC6A8 gene. Mothers with an affected son with a de novo mutation should be counselled about a recurrence risk in further pregnancies due to the possibility of low level somatic or germline mosaicism. Missense mutations with residual activity might be associated with a milder phenotype and large deletions extending beyond the 3' end of the SLC6A8 gene with a more severe phenotype. Evaluation of the biochemical phenotype revealed unexpected high creatine levels in cerebrospinal fluid suggesting that the brain is able to synthesise creatine and that the cerebral creatine deficiency is caused by a defect in the reuptake of creatine within the neurones
    2013-07Journal article Restricted access Show more