Etiology and the Genetic Basis of Intellectual Disability in the Pediatric Population

Abstract

Intellectual disability/mental retardation (ID/MR) is defined as incomplete mental and cognitive development present before the age of 18. There are number of pre-natal and post-natal risk factors that can cause ID/MR but25 %-50% of all have genetic causes. In the general population,the prevalence of ID/MR is about 2 %-3%. Use of standard cytogenetic methods analysis of chromosomes (GTG banding) and FISH (Fluorescent in Situ Hybridization) reveals only a small number of causes, but when usingnew molecular genetics techniques (like chromosomal microarray and next generation sequencing), the rate of causes of ID/MR is increasedand new candidate genes for ID/MR have been discovered. Establishing a diagnosis of ID/MR is important for the patient and it provides genetic counseling for parents.