Identification of Susceptible Copy Number Variants in a Palestinian Family affected with Intellectual Disability

Abstract

Intellectual disability (ID) is a common problem with major implications for the public health, education and community services. The causes of mental retardation have been found to have a definite etiological basis, which may be biochemical, chromosomal, mendelian genetic disorders, or due to environmental effects. The underlying causes remain unknown in a significant percentage of cases, but genetic causes account for 25-50% of such cases. In the present study, we undertook the challenge of identifying genes involved in ID by performing genome-wide copy number variation analysis of one consanguineous Palestinian family with 3 kids of intellectual disability using cytoscan high density microarrays. We identified copy number variants implicating genes on the chromosome11 (DLG2) as well as chromosome X (1ILRB1) as ID candidate genes. Our findings highlight the importance of chromosome 11and X in the etiology of intellectual disability, and demonstrate the power of copy number variation analysis in the identification of disease genes, in particular for complex genetic disorders such as intellectual disability