Detection and consequences of imbalances in the human genome

Abstract

Genomic imbalances (GIs) are an important class of variation in the human genome. Many of them are related to diseases and responsible for the phenotype in a substantial number (10 - 20%) of individuals with congenital anomalies (CA) and (or) intellectual disability (ID)/ developmental delay (DD). Currently, the chromosomal microarray analysis (CMA) is pointed as a first tier for the molecular diagnosis of this group of patients. Nevertheless, studies published recently have been suggested that the whole exome sequencing (WES) could substitute the CMA as the first diagnostic test, considering that the latter is able to identify both small nucleotide variants (SNVs) and GIs, in a single experiment. However, to date, there are few studies with patient groups and there is not a consensus about this substitution yet. On the other hand, a constant challenge in the interpretation of GIs detected by CMA, in individuals with CA and (or) ID/ DD, is the identification of variants of unknown significance (VUS). Recently, a study suggested that the WES would be necessary to clarify cases with ID/ DD and VUS. The aims of this project are: to perform the WES and search for SNVs related to the phenotype in individuals with CA and (or) ID/ DD, and VUS detected previously by CMA; and to identify the GIs detected previously by the CMA, performing GIs analysis in the WES data, in the same group of individuals. 50 individuals with CA and (or) ID/ DD and VUS detected by CMA will be selected. The WES will be performed, followed by two analyses: the search for SNVs related to the phenotype and the search for GIs in the WES data. (AU)