Angus John Clarke

Improved definition of carrier status in X-linked hypohidrotic ectodermal dysplasia by use of restriction fragment length polymorphism-based linkage analysis

The detection of carriers of the X-linked disorder hypohidrotic ectodermal dysplasia is problematic because of random X-inactivation; the diagnosis was previously based on the observation of subtle defects in ectodermal structures in at-risk females. Linkage studies have recently mapped hypohidrotic ectodermal dysplasia to the region Xq11-q21.1. We assessed the improvement in carrier detection by the method of linkage analysis, in which restriction fragment length polymorphisms were used as markers, in 72 at-risk female members of 29 families. Carriers analyses were based on pedigree information, dental examination of at-risk females (phenotype), and DNA analyses at seven linked marker loci. Linkage analysis based on restriction fragment length polymorphisms significantly improved risk estimates over those based on phenotype and pedigree alone. When all available information was combined, 85% (61/72) of the at-risk females had final risks of less than 5% or greater than 95%, and 68% (49/72) had risks less than 1% or greater than 99%. A diagnosis of hypohidrotic ectodermal dysplasia was also excluded (97.5% probability) by DNA and linkage analyses from a sample of cord blood from an at-risk male; a similar approach can be taken for prenatal diagnosis of the disorder.

Professional explanations of disease trajectories: The case of Type 2 Diabetes and Coronary Heart Disease

Media representation of health and illness is a common pursuit of discourse analysts. Less common is the study of how healthcare professionals and researchers provide explanations about health and disease in interview situations. In this paper we focus on professional explanations concerning Type 2 Diabetes and Coronary Heart Disease which are major health problems in the Western world, consuming a significant percentage of the health budget in many countries. Efforts to halt the increasing incidence are directed, in part, to understanding the causes of both illnesses. As part of a larger project aimed at understanding causal explanations for these conditions, we interviewed 18 clinicians and researchers working in the field in the UK to determine their views on why the incidence of these conditions continues to rise worldwide. We adopt a rhetorical discourse analytic perspective to highlight the function and significance of raising these issues as causal explanations. While scientific physiological and epidemiological explanations reflecting current research featured in the interviewees’ accounts, of greater interest were the explanations of socioeconomic and political factors that contribute to the ongoing epidemic through the mediating physiological processes.