Comparison of ACGH and MLPA method for detection of KANSL1 gene deletion

Microdeletion and microduplications are detected on chromosomes as a pathological subgroup of copy number variants (CNV) of DNA. Sizes can change from one kilobase to several megabases. It has become easier to identify such chromosomal syndromes after use of array-based comparative genomic hybridization (aCGH) technology. One of them is 17q21.31 microdeletion and microduplication syndrome. Copy loss in size of 500-650 kb in the regions 17q21.31 which is describe as Koolen-de Vries Syndrome (KdVS) includes mental retardation, epilepsia, hypotonia and characteristic facial features. Novodays, we know that haplo-insufficiency of KANSL1 gene in this region is sufficient for occure of theses 17q21.31 microdeletion syndrome findings. In this study, 30 patients with a loss of copy number including the KANSL1 gene in 17q21.31 microdeletion region as a result of aCGH were examined by MLPA method again. As a result of this comparison, only three of the 30 patients had a deletion of the KANSL1 gene and duplication was found in one patient. The outcome of a patient can not be assessed due to procedural reasons. This study was show that if KANSL1 gene loss were detected by aCGH, it would be wrong to report it without being validated by clinical evaluation and another method.