There is no single cause of intellectual disability. There are many risk factors to contribute as well as the timing of these factors Even if the factors can be identified the exact cause can be difficult to determine.

Prenatal- chromosomal disorders and brain formation disorders

Perinatal-injury during birth, prematurity

Postnatal-brain injury or infections

Four Main Risk Factors:

1.Biomedical factors like genetic disorders and nutrition

2. Social factors related to stimulation and adult responsiveness

3. Behavioral factors like dangerous activities and maternal substance abuse

4. Educational factors like availability of support that promote development

I. Observation-Child does not reach appropriate developmental milestones or has characteristics of a particular syndrome

II. Screening- Reading comprehension and math reasoning are limited, student may be identified by a physician

III. Prereferral-Student continues to manifest limitations in adaptive behavior despite interventions

IV. Referral- This would be a team submission

V. Nondiscriminatory evaluations procedures and standards- The student has sub average intellectual functioning with IQ standard score of 70 or below. This is the bottom 2 to 3 percent of the population. The student experiences difficulty in making progress in the general education classroom.

VI. Determination- Decision made by multidisciplinary evaluation team.