genetics services

Healthcare professionals trying to keep up with rapid developments in genetic science and their implications for the NHS can now tap into the expertise of a specialist unit, explains Ron Zimmern

There is a story on some aspect of genetic or molecular science in the media almost every day. The growing importance of developments in these fields for clinical practice - and for the NHS as a whole - is obvious to all those concerned with strategic planning. We must prepare for the possibilities created by genetic science, and its impact.1,2

Tomorrow's world

Advances in genetics and molecular biology raise several service issues.

There is little validated data on the activity of, or investment in, clinical genetic services by health authorities. The Public Health Genetics Unit in Cambridge is reviewing the data which is available and considering how genetic services might best be commissioned in future years.

Medical genetic services in the UK have largely been responsible for managing rare Mendelian disorders which tend to run in families. Medical geneticists have developed expertise and facilities across a network of regional genetics centres.

In dealing with families with inherited genetic disorders, medical geneticists have paid particular attention to ethical and social aspects of the genetic consultation, and have developed strong links with scientists in molecular and cytogenetic laboratories.

Continuing and strengthening these services is a high priority. The growing understanding of the role of genetic factors in the pathogenesis of many common diseases, such as diabetes, heart disease, Alzheimer's and cancer, will add to pressure on these services. In the longer term, how services are organised to address the genetic implications of these common disorders must be addressed - in particular, the training implications for other specialties, the role of genetic associates, and how some services might be provided in a primary care setting.

In partnership with the Nuffield Trust, the PHGU has established a project to assess the impact of advances in genetics and molecular biology on the organisation, funding and provision of clinical services, on changes in clinical practice, and on the potential for disease prevention and public health action. The project starts this month.

The PHGU has worked with colleagues in cancer genetics to establish guidance on treating women with a family history of breast cancer.

A national conference in January 1998 established principles of care on which there was broad consensus. The concept that women anxious about breast cancer can be placed into one of three risk groups - low, moderate and high - on the basis of their family history, with different management strategies according to the level of risk, is now widely accepted.3 There is still debate about the exact criteria that separate the risk groups.

Testing times

Modern genetics makes abundantly clear that disease risk, in practically all circumstances, is determined in part by genetic risk and in part by environmental risk. At times genes and the environment can interact to confer a far greater disease risk than would be expected by adding the individual genetic and environmental risks.

Prevention may be through intervention at the level of the genome - which in practice means eugenic measures such as taking the decision not to reproduce - or through some form of pre-natal testing followed by abortion, or selectively influencing the environment for sub-populations in which mutations and polymorphisms which confer a greater environmental risk are identified.

In therapeutic situations, identifying these sub-populations may allow a much more specific use of pharmaceutical agents. More effective and safer drugs with fewer side-effects would benefit patients and have wider benefits through more

cost-effective use of increasingly expensive drugs.4

The PHGU believes that while testing and diagnosis followed by abortion is an important and legitimate clinical activity, this activity must be seen in a clinical - as opposed to a population or public health - context. The aim has to be to provide information and reproductive choice to individual couples.

Any attempt to bring such testing into a population programme designed to reduce the birth prevalence of certain genetic disorders would lead to difficult, and probably unnecessary, ethical dilemmas.

By contrast, the identification by genotype of sub-populations who might be at greater environmental risk could lead to effective structural, behavioural or clinical interventions as a means of prevention.

Such strategies raise complex issues about the computation and communication of risk in the clinical consultation. Much more research is needed to determine the most appropriate and effective interventions.

The PHGU will keep a close eye on the literature and work closely with the Institute of Public Health in Cambridge, where a number of major research groups work on gene-environment interaction in fields as diverse as cancer, osteoporosis, diabetes, heart disease and Alzheimer's disease.

There is little real understanding among most of those who work in the NHS of the longer-term implications of genetic science. But there is evidence of increased interest in the subject. The huge amount of activity concerned with increasing public understanding of science is also encouraging. People with an interest in genetic science policy issues believe in the importance of ensuring a greater public understanding of genetics and its ethical and social implications.

The PHGU is there to help managers and other NHS staff keep pace with the rapid changes in genetics, and the challenge these pose for policy and practice.

www.medinfo.cam.ac.uk/phgu