Cytogenetic surveillance of mentally-retarded school children in southern Taiwan.

Background And Purpose: Mental retardation (MR), defined as having an IQ of less than 70, is present in approximately 2 to 3% of the population. Data on chromosomal abnormalities, an important cause of MR, are limited in the Taiwanese literature. This study evaluated the frequency and pattern of chromosomal abnormalities in school children with MR in southern Taiwan.