Investigation of submicroscopic chromosomal anomalies on patients with idiopathic mental retardation with molecular karyotyping

Mental retardation and/or congenital anomalies are rarely seen on general population, but have a large etiologic spectrum. Structural chromosomal abnormalities are one of the significant reasons of mental retardation, dysmorphism and congenital anomalies. Conventional cytogenetic techniques can only detect abnormalities greater than 5 Mb. In the diagnostic process there are locus specific or subtelomeric FISH analyses that can be performed on patients whose karyotype revealed as normal. If the clinical symptoms still make us think about chromosomal abnormality, array based methods can be useful to detect anomalies smaller than 3 Mb to kilobase levels with a ratio of % 10-15. As a result, small interstitial deletions and duplications could be detected with microarray technique that integrates conventional and molecular cytogenetic procedures.In this study, 9 patients with idiopathic mental retardation and/or congenital anomaly, growth retardation and normal detected chromosome and subtelomeric FISH analyses, had been investigated for small deletions or duplications with ?Genome Wide SNP 2.7 Array? and the diagnostic yield of these microarray technologies has been confirmed with detection of one causative anomaly on a patient.