Phenotype definitions: some hidden issues in psychiatry.
Three hidden problems in phenotype definition in psychiatric genetic studies are described. 1. Data on physical conditions in family members are not routinely collected in genetic studies of psychiatric disorders. These data may reveal cosegregation with psychiatric disorders which can be included in genetic analysis when defining the phenotype. Data on physical conditions can be obtained by a combination of medical checklists, medical history, and medical records. 2. Detailed clinical narrative summaries should be prepared on family members even if the narratives are not part of the diagnostic data included in centralized cell repositories for future distribution to qualified genetic investigators. Means for retaining the narratives for future use, while protecting patient confidentiality, should be sought. The narratives include detailed information on the context, severity, and sequence of the symptoms and can provide phenotype descriptions for reconsideration of diagnosis in the future. 3. The selection of early onset psychiatric disorders for genetic studies does not automatically mean that affected children should be included in genetic studies for some psychiatric disorders. Screening for genetic studies among child psychiatric patients and inclusion of children as affected in pedigrees should proceed with caution until more data are available from longitudinal studies on the continuity between childhood and adult psychiatric disorders.
Weissman
M M
MM
Division of Clinical and Genetic Epidemiology, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA. Weissman@child.cpmc.columbia.edu
D000328:Adult; D001526:Behavioral Symptoms / Q000235:genetics; D002648:Child; D008040:Genetic Linkage; D006801:Humans; D008137:Longitudinal Studies; D008487:Medical History Taking; D001523:Mental Disorders / Q000235:genetics*; D010641:Phenotype