Article

Molecular karyotyping is an extremely suitable method for genetic diagnosis of patients with unclear dysmorphic syndromes and intellectual disability. In this study we present our results from microarray analysis of 52 patients with developmental delay and congenital malformations. Our data revealed definite etiology in 9 out of 52 patients tested. Fifteen pathological aberrations were found in them. All pathological findings were validated by fluorescent in situ hybridization (FISH) analysis. In addition, the majority of the patients tested (41 patients) showed normal variations in the number of copies and variations of unknown clinical significance (34 patients). Analyses of the type and distribution of the different variations was performed and the clinical significance of variants of unknown nature was discussed. Our results show the advantages of high resolution microarrays for clinical diagnosis of patients with intellectual disability and congenital malformations, and also highlight the need for extensive population studies revealing the molecular nature and clinical significance of different copy number variations and for creation of detailed maps of variations in the Bulgarian population.