Mental retardationMental retardation (MR) refers to a group of disorders that have in common deficits of adaptive & intellectual function & an age of onset before maturity is reached. According to statistics, 2.5% of the population should have MR, & 85% of these individuals should fall into the range of mild MR.PresentationMR presents by the age of the patient, i.e.Newborn : Dysmorphism, major organ system dysfunction. Early infancy (2-4 months) : Failure to interact with the environment, vision & hearing impairment. Late infancy : Gross motor delay Toddlers (2-3 yrs) : Language delays & difficulties. School age (over 5 yrs) : Academic underachievement & behaviour difficulties. Predisposing factors for mental retardation i)    Low socio - economic strata              iii) Advanced maternal age           v) Genetically transmitted Low birth weight                iv) Consanguinity