Abstract
Chromosomal aberrations are the most common known cause of mental retardation. However, the typical rearrangement is below a resolution limit of standard cytogenetic banding.
MLPA is a modern molecular genetics method of choice that can detect such small deletion/duplication in a number of selected regions at a time. Our sample was made of 41 unrelated probands in charge of the Department of Medical Genetics (GTH and 1stFM, Charles University in Prague).
Selection criterions were the presence of mental retardation corresponding to cryptic rearrangements but without a positive cytogenetic finding on a standard cytogenetic karyotyping. We have analysed all probands using MLPA kits P245 for detection of 21 most common deletion/duplication syndromes, P036 for the subtelomeres analysis, and P297 designed to examine new chromosomal regions recently associated with mental retardation.