Navegando por Palavras-chave "DiGeorge syndrome"

Agora exibindo 1 - 1 de 1
  • Imagem de Miniatura
    Item
    Embargo
    Avaliação de pacientes com o espectro clínico da síndrome da deleção 22q11.2 através de hibridização in situ por fluorescência e da técnica multiplex ligation-dependent probe amplification
    (Universidade Federal de São Paulo (UNIFESP), 2010-04-28) Pacanaro, Ade Nubia Xavier [UNIFESP]; Moraes-Pinto, Maria Isabel de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Introduction: The 22q11.2 deletion is the most frequent human microdeletion syndrome. The phenotype is highly variable and characterized by conotruncal heart defects, facial dysmorphism, velophalangeal dysfunction, hypoparathyroidism, thymic hypoplasia, learning disabilities, and mental retardation. Purpose: To investigate patients with clinical phenotype of the 22q11.2 deletion syndrome considering the presence, origin and extension of the deletion. To investigate other genomic region unbalances related to the syndrome. To correlate the different segments deleted with the phenotype. Methods: We studied 70 patients with diagnostic hypothesis of 22q11.2 deletion syndrome. Cytogenetic analysis was performed using G-banding. We used FISH (fluorescence in situ hybridization) technique in order to evaluate the deletion presence and origin, and MLPA (multiplex ligation-dependent probe amplification) technique in order to identify deletions and to determine their sizes and also, to evaluate other chromosomal region unbalances. Results: The cytogenetic analysis using G-banding showed normal karyotypes in all patients, except in one that was 48,XXXX. We found 21 patients with deletion and 49 patients with normal results, using the FISH and MLPA approaches. Among the 18 deletions investigated with MLPA, 13 were 3 Mb deletion (72%), two were 1,5 Mb deletion (11%) and three were atypical deletions (17%). Two were inherited deletions. Conclusions: Among patients with the phenotype of 22q11.2 deletion syndrome, we found 30% cases of 22q11.2 deletion. The phenotype correlation with the different size deletions is not well established considering the wide phenotypic variation found either in patient with typical deletions of 3 Mb or in patients with smaller and atypical deletions. The frequency of phenotypic features did not differ significantly between deleted and not deleted patients’ groups. Considering the great phenotypic variability among patients with different deletions and the clinical characteristics overlapping with the ones present in not deleted patients, it is important molecular approaches for the diagnosis. FISH and MLPA approaches have proved successful in the investigation of 22q11.2 deletion, although only MLPA technique is able to determine the 22q11.2 deletion extension.