Mental retardation is a condition that affects 2%-3% of the population and more than half of the cases are still deemed idiopathic. Its etiology is heterogeneous and chromosome abnormalities play a significant role. The application of classical cytogenetic and molecular cytogenetic techniques has enabled accurate diagnosis in several cases, which allows better clinical monitoring and genetic counseling. This paper aims at informing about the major tests currently available to investigate chromosome abnormalities in patients with idiopathic mental retardation, including GTG-banded karyotyping, fluorescence in situ hybridization (FISH), spectral karyotyping (SKY), multiplex ligation-dependent probe amplification (MLPA) and array-comparative genomic hybridization (array-CGH).
Mental retardation; Karyotype; FISH; SKY; MLPA; Array-CGH
