Genetics and child psychiatry: I advances in quantitative and molecular genetics

Advances in quantitative psychiatric genetics as a whole are reviewed with respect to conceptual and methodological issues in relation to statistical model fitting, new genetic designs, twin and adoptee studies, definition of the phenotype, pervasiveness of genetic influences, pervasiveness of envir onmental influences, shared and nonshared environmental effects, and nature -nurture interplay. Advances in molecular genetics are discussed in relatio n to the shifts in research strategies to investigate multifactorial disord ers (affected relative linkage designs, association strategies, and quantit ative trait loci studies); new techniques and identified genetic mechanisms (expansion of trinucleotide repeats, genomic imprinting, mitochondrial DNA , fluorescent in-situ hybridisation, behavioural phenotypes, and animal mod els); and the successful localisation of genes.