Mental retardation; molecular cytogenetic techniques used for diagnosis; a literature survey

ABSTRACT

Mental retardation, also termed as learning impairment or cognitive dysfunction, is a serious manifestation of nervous system. The defining features of mental retardation are low or subaverage intellectual functioning [Intelligence quotient<70], impairment in at least two of the adaptive skills [e.g communication ability, self care, self guidance, reading, writing ability, etc] before 18 year of age1. Molecular cytogenetics is the study of genetic disorders using advanced technologies combined with cytogenetic and molecular methodologies2. Molecular diagnosis has equal importance as clinical diagnosis in mental retardation and day by day new advancement in these methodologies are being introduced by molecular cytogeneticists. The promising achievement of molecular cytogenetic techniques is the genetic counseling of high risk pregnancies. The current mini-survey of literature discusses an overview of these techniques employed to investigate deletion, duplication, inversion and translocation of chromosomes associated with mental retardation