This article presents a critical review of literature on genetics of mental …

• Abstract
• Idiopathic mental retardation
• Single-gene defects
• Fragile X syndrome
• Chromosomal abnormalities
• Down syndrome
• Microdeletion syndromes
• Prader-Willi syndrome
• Angelman syndrome
• Sex chromosome anomalies
• Turner's syndrome
• Klinefelter's syndrome
• Conclusions
• References
• Figures

Recent advances in identifying previously undetected sub-microscopic chromosomal anomalies have proven to be successful. They highlight the fact that many cases of idiopathic mental retardation may have specific aetiologies, which may not yet be discovered. Given the increased interest in studying behavioural phenotypes associated with some of these conditions, it is hoped that the localization of specific genes and the identification of genes within critical chromosomal regions might pave the way for understanding more about the genetic basis of behaviour and psychiatric disorders.

The challenge for the future is to unravel the complex interaction between genes and environment using well-designed twin and adoption studies as well as molecular genetic strategies so as to determine the extent to which genes and environment contribute, co-act and interact in determining intelligence. Such research will contribute in planning appropriate interventions.