Behaviour phenotypes of genetic disorders

Purpose of review The aim of this article is to survey recent advances in understanding the cognitive and psychopathological profile of genetic disorders causing intellectual disability. In addition, it will review developments in knowledge of the biology underlying these disorders. Recent findings In the Prader-Willi syndrome, the excess levels of the appetite stimulating hormone ghrelin have been increasingly linked to the severe psychopathology often seen in this disorder. Specific cognitive deficits and the prevalence of psychosis may be linked to genetic subtypes of Prader-Willi syndrome. In Fragile X syndrome, studies have elucidated the impact of DNA changes on the production of the key protein: Fragile X mental retardation protein. Whilst deficiency of this protein clearly produces changes in dendritic morphology and function the correlation between measured Fragile X mental retardation protein and behavioural and cognitive pathology remains unclear. Mental health problems have been increasingly identified in premutation carriers of Fragile X syndrome. Cognitive and linguistic development have been explored in the velocardiofacial syndrome and there are new data on the link between abnormalities in enzyme function in this syndrome and the increased prevalence of psychosis. Lastly, a number of comparative studies have demonstrated the significant differences in profiles of psychopathology in genetic disorders causing intellectual disability. Summary Recent advances have contributed significantly to our understanding of the gene-to-behaviour pathways in these conditions, thereby increasing the opportunity to develop specific treatments to ameliorate them.