engleski

FISH analysis in children with developmental delay, dysmorphism and malformations

Chromosome aberrations are frequent cause of developmental delay, dysmorphism and congenital malformations. Cytogenetics has low resolution power and chromosome anomalies smaller then 5 Mb cannot be detected. FISH is useful method for detecting submicroscopic rearrangements. In this report we present the results of FISH study in 140 children with developmental delay, dysmorphism and congenital malformations (DDM). The FISH method with microdeletion probes and ToTelVysion multicolor FISH panel for subtelomeric screening was performed according to the manufacturer's suggestions (Vysis). Microdeletions were detected in 14(11.0%) out of 127 children with phenotype suggestive of microdeletion syndromes. FISH analysis revealed hemizygocity for 22q11.2 in 7(6.7%) and re-evaluation revealed deletion of ELD locus in 2(1.95) additional patients out of 104 suspected for DiGeorge/VCFS. Williams syndrome was diagnosed in 3 (37.4%) out of 8 patients, Angelman in 1, and deletion of SNRPN locus in 3(50%) out ot 6 children referred for Prader-Willi syndrome. Subetlomeric FISH revealed no rearrangement in 9 patients with DDM and normal karyotype and contributed to the precise characterization of 4 investigated structural chromosomal aberrations with suspected involvement of telomere. This report confirms that FISH is powerful method for diagnosis of microdeletion syndrome. Although no rearrangement was detected by subtelomeric screening in this small group of patients, this study points that multisubtelomere FISH is useful in understanding the mechanism of origin of structural rearrangemetns, and emphasize the need of selection criteria and precise phenotype evaluation of the patients prior to subtelomeric testing. Supported by the Ministry of Science of the Republic of Croatia (TP-01/072-01).

FISH; developmental delay; dysmorphism; malformations

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