Insights into Common Microdeletion Syndromes

Microdeletion syndromes are due to submicroscopic chromosomal deletions and display a complex clinical and behavioral phenotype. This occurs because of an imbalance of normal dosage of genes that are present in that segment of chromosome. Many clinical characteristics of the well-known microdeletion syndromes are very specific and have been well defined. It is not always possible to detect these microdeletions by using the conventional or high resolution karyotyping. This necessitates the application of molecular cytogenetic techniques and the recent widespread usage and an in-depth knowledge of methods such as G-band karyotyping, multiples ligation-dependent probe amplification (MLPA), quantitative fluorescent PCR (QFPCR), sequencing and microarray-based comparative genomic hybridization (array CGH) had further led to identification of new microdeletions and sound description of identification of new microdeletion syndromes. This review appraises the common microdeletion syndromes focusing on the incidence rate, clinical manifestations and the mechanism involved therein.