Developmental disorders are a group of early and chronic disorders affecting 5-10% of children.
Developmental delay is a subtype defined as significant delay in two or more of the following
developmental domains: motor (gross and fine), language (receptive an expressive), cognition, social and
adaptive activities. The estimated prevalence of global developmental delay is 1-3% of children younger
than 5 years. Developmental delay is a clinical presentation of a wide variety of congenital or acquired
etiologies. It results in significant learning deficits incompatable with the child’s chronological age.
Significant delay in a given developmental domain is defined as performance two standard deviations or
more below the mean for age. The term developmental delay is usually reserved for younger children (less
than 5 years of age), whereas the term mental retardation is usually applied to older children when IQ testing
is more reliable.
Keywords: Neurological, Development, Disorders, Assessment, Delay, Regression, Evaluation, Mental
retardation, Genetic, Metabolic.
