The development of a practical screening procedure for phenylketonuria and the improvement in methods of chemical analysis have led to a realization that Folling's (1934) disease of phenylketonuria is not a single entity. In this commentary, the current view on some aspects of phenylketonuria will be reviewed and the problems illustrated by experience gained in the Phenylketonuria Clinic at the...

The authors administered inventories of vocational and recreational interests and talents to 924 pairs of twins who had been reared together and to 92 pairs separated in infancy and reared apart. Factor analysis of all 291 items yielded 39 identifiable factors and 11 superfactors. The data indicated that about 50% of interests variance (about two thirds of the stable variance) was associated wi...

Continuing uncertainty about the etiology of schizophrenia calls for periodic reappraisal of relevant data and conclusions, reappraisals guided by a beacon of modest doubt to avoid the distorted views of both the zealot and the skeptic. This review does not set out to cover every possible aspect of the genetics of schizophrenia. It deals with data from recent family, twin, and adoption studies ...

A substantial part of the contribution of genetic studies to the treatment of schizophrenia involves its emphasis on reliable and valid diagnoses. One consequence of this focus is the recognition that schizophrenic illness is broader than the diagnostic entity of schizophrenia itself, and instead consists of a "spectrum" of related disorders. Because some of the symptoms in these disorders diff...

In this paper register based family studies provide the motivation for linking a two-stage estimation procedure in copula models for multivariate failure time data with a composite likelihood approach. The asymptotic properties of the estimators in both parametric and semi-parametric models are derived, combining the approaches of Parner (2001) and Andersen (2003). The method is mainly studied ...

Telomere length (TL) is emerging as a biomarker for aging and survival. To evaluate factors influencing this trait, we measured TL in a large homogeneous population, estimated the heritability (h(2)), and tested for parental effects on TL variation. Our sample included 356 men and 551 women, aged 18-92 years, from large Amish families. Mean TL in leukocytes was measured by quantitative PCR (mea...

The area of our research is the phenomenon of social influence process and the role of person's and group's mentality in the conflict. Conflict implies the existence of at least two sides or parties, majority and minority (by its number, territory, resources and etc.). Until now the role of majority in social influence process was mainly studied considering the existing numerous psychological r...

The use of survival time models with non-proportional hazard functions is introduced as a method of studying age of onset effects in family studies. Statistical methods for investigating non-proportionality of the hazard function are described, and the application of these methods is illustrated using data from a family study of depression to investigate transmission of age of onset between pro...

The purpose of this paper was to review the theoretical underpinnings, major concepts, and methods of the typological approach. It was argued that the typological approach offers a systematic, empirically rigorous and reliable way to synthesize the nomothetic variable-centered approach with the idiographic case-centered approach. Recent advances in cluster analysis validation make it a promisin...