Molecular genetics of common diseases

Nutrigenetics and nutrigenomics insights into diabetes etiopathogenesis

Diabetes mellitus (DM) is considered a global pandemic, and the incidence of DM continues to grow worldwide. Nutrients and dietary patterns are central issues in the prevention, development and treatment of this disease. The pathogenesis of DM is not completely understood, but nutrient-gene interactions at different levels, genetic predisposition and dietary factors appear to be involved. Nutritional genomics studies generally focus on dietary patterns according to genetic variations, the role of gene-nutrient interactions, gene-diet-phenotype interactions and epigenetic modifications caused by nutrients; these studies will facilitate an understanding of the early molecular events that occur in DM and will contribute to the identification of better biomarkers and diagnostics tools. In particular, this approach will help to develop tailored diets that maximize the use of nutrients and other functional ingredients present in food, which will aid in the prevention and delay of DM and its complications. This review discusses the current state of nutrigenetics, nutrigenomics and epigenomics research on DM. Here, we provide an overview of the role of gene variants and nutrient interactions, the importance of nutrients and dietary patterns on gene expression, how epigenetic changes and micro RNAs (miRNAs) can alter cellular signaling in response to nutrients and the dietary interventions that may help to prevent the onset of DM.

Transfer of DNA tests from research to routine laboratories: some lessons from the French experience in the case of Duchenne muscular dystrophy

In the last few years, the activity of research laboratories has led to the emergence of new DNA diagnostic tests in France. They permit the origin of genetic diseases to be identified and provide an answer concerning the detection of carriers and prevention. Nevertheless, given this, new actors have emerged on the health care scene: the research workers who developed the tests and who work in public research laboratories. The economic question of the transfer of the test practice from research to hospital laboratories is the main topic of this paper, taking Duchenne Muscular Dystrophy (DMD) DNA diagnostic tests as the example. After a presentation of the complexity of DNA tests for DMD, the fact that financial and human constraints do not allow the actors to continue to produce the DNA tests is discussed. The financial role of the non-profit-making associations is then explained and leads to the conclusion that a more global policy on DNA tests, such as carried out in the UK and the Netherlands, should be adopted in France by the Social Security if it wants DNA testing activity to be pursued.

The Human Genome Project and eugenic concerns

The U.S. Human Genome project is the largest scientific project funded by the federal government since the Apollo Moon Project. The overall effect from this project should be of great benefit to humankind because it will provide a better understanding both of single gene defects and multifactorial or familial diseases such as diabetes, arteriosclerosis, and cancer. At first this will lead to more exact ways of screening and diagnosing genetic disease, and later it will lead, in many if not most instances, to specific genetic cures. However, in the past, in both the U.S. and German eugenic movements genetic information has been misused. Hopefully, by remembering and understanding the past injustices and inhumanity of negative eugenics, further misuse of scientific information can be avoided.

Discrimination as a consequence of genetic testing

Genetic discrimination refers to discrimination directed against an individual or family based solely on an apparent or perceived genetic variation from the "normal" human genotype. We describe here the results of a case history study designed to assess whether or not genetic discrimination exists. Using the above definition of genetic discrimination and applying stringent criteria for case selection, we find that genetic discrimination exists and is manifested in many social institutions, especially in the health and life insurance industries. Stigmatization, and denial of services or entitlements to individuals who have a genetic diagnosis but who are asymptomatic or who will never become significantly impaired, is noted. Follow-up comprehensive studies on the significance and varieties of genetic discrimination are needed. In order to avoid creating a new social underclass based on genetic discrimination (the "asymptomatic ill"), existing and future genetic testing or screening programs need review by medical, scientific, legal, and social policy experts, as well as the public, and may require modification.

Applications of molecular genetics to gastrointestinal and liver diseases. II. Clinical relevance

The use of DNA probes within or near disease genes is becoming increasingly important in clinical medicine. Probes are available for prenatal and carrier diagnosis for several of the more than 100 genetic diseases of the gastrointestinal tract and liver. These include familial adenomatous polyposis, haemochromatosis, cystic fibrosis, alpha 1-antitrypsin deficiency and the hereditary porphyrias. This review uses examples drawn from such diseases to show the relevance of these approaches to the clinician.

The impact of molecular genetics on our understanding of the psychoses

Studies demonstrating the linkage to separate chromosomal locations of Alzheimer's disease, manic depression, and schizophrenia require re-evaluation of our ideas of their genetic aetiology. This article reviews the findings, and explores the increasing contribution of the 'new genetics' to our understanding of the organic and functional psychoses.

Molecular genetics in the National Health Service in Britain

A recent report from the Departments of Health draws attention to the value of DNA diagnosis for inherited diseases and the need for planning these services in the National Health Service. There is great potential for preventive medicine, but a major immediate benefit is the newfound ability to exclude the carrier state in many people at risk and to protect fetuses from abortion when, as in most cases, they are shown to be normal by DNA tests. However, the widespread application of these new techniques requires prior evaluation and general acceptance. This will only be obtained after public debate, education of professionals and the population, and the establishment of adequate non-directive genetic counselling services. Some of the points to be considered in setting up molecular genetics laboratories are described.

Current status of tumor markers in large bowel cancer

The aim of a primary screening system is to detect premalignant lesions and carcinomas when amenable to "curative" surgery. Although a number of "classical" tumor markers have acquired potential for clinical management, none is presently adequate for presymptomatic diagnosis or screening. In colorectal carcinoma, the screening potential of carcinoembryonic antigen (CEA), the gastrointestinal-related antigen, CA19-9, and other more recently characterized "biochemical markers" is virtually nonexistent, even in patients at high risk to develop the disease. Promising new leads are beginning to emerge from somatic cell genetic and molecular biological approaches. In common with other epithelial neoplasms, perturbations in oncogene expression have been demonstrated in colorectal cancers, and probably reflect important events in malignant transformation and progression. Studies of oncogene expression have, however, not yet yielded clinically useful information. Recently, an intensive search for specific chromosomal and gene abnormalities in the hereditary colon cancer syndromes led to the location of the familial adenomatous polyposis (FAP) gene at chromosome 5q21-q22. Significant is that the loss of alleles on chromosome 5 has also been observed in the tumor cells of at least 20% of sporadic colon cancer patients. This type of association between constitutional genetic change and genetic aberration in the cells of sporadic tumors is reminiscent of other malignant diseases with a genetic component (e.g., retinoblastoma and Wilms' tumor).(ABSTRACT TRUNCATED AT 250 WORDS)