Integrating genotypic data with transcriptomic and proteomic data

Historically genotypic variation has been detected at the phenotypic level,at the metabolic level, and at the protein chemistry level. Advances in technologyhave allowed its direct visualisation at the level of DNA variation. Nevertheless,there is still an enormous interest in phenotypic, metabolic and protein propertyvariability, since such variation gives insights into potential functionallyimportant differences conferred by genetic variation. High‐throughput transcriptomicsand proteomics applied to different individuals drawn from a population hasthe potential to identify the functional consequences of genetic variability,in terms of either differences in expression of mRNA or in terms of differencesin the quantities, pI(s) or molecular weight(s) of an expressed protein. Familystudies can define the genetic component of such variation (segregation analysis)and with the genotyping of well‐spaced markers can map the causative factorsto broad chromosomal regions (linkage analysis). Association studies in thevariant proteins have the greatest power to confirm the presence of cis ‐actinggenetic variants. The most powerful study designs may combine elements ofboth family and association studies applied to proteomic and transcriptomicanalyses. Such studies may provide appreciable advances in our understandingof the genetic aetiology of complex disorders. Copyright © 2002 JohnWiley & Sons, Ltd.