Demand for DNA probe testing in three genetic centres in Britain (August 1986 to July 1987)

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.

Delivery of molecular genetic services within a health care system: time analysis of the clinical workload. The Molecular Genetic Study Group

The most recent discoveries in molecular genetics today are rapidly incorporated into clinical practice and have resulted in an unprecedented expansion of medical options. Despite this, the impact of molecular genetics on health care services has yet to be evaluated. In order to begin this assessment, clinical genetic workload was prospectively collected from cases where molecular genetic testing was considered. Participation involved all 16 urban and outreach genetic centers regionalized to service the entire population of 10 million within the Canadian province of Ontario. Molecular genetic testing has been clinically available for > 5 years, as part of a publicly supported genetic network in which there are no direct costs to residents. Cross-sectional data were collected on 1,101 clients from 544 families involving 1,742 clinical actions relating to diseases in which molecular (DNA) tests were considered. Median times per clinical genetic action were as follows: formal counseling (60 min), case review (15 min), phone call (10 min), letter (15 min), specimen arrangement (15 min), and interpretation of molecular test results (10 min). Times varied significantly with the inheritance pattern of the disease, topics involved, and location. For any given genetic case, multiple clinical actions resulted in substantial time spent by the genetic professional. Clerical and administrative times were not captured. Workload unit measurements similar to those currently employed in hospital laboratories may be helpful for predicting the clinical resources and personnel that will be required as the use of molecular genetics by other medical specialties increases.

DNA probe technology: implications for service planning in Britain

For certain genetic conditions DNA testing identifies carriers and determines the risk status of foetuses, thus helping parents to make more informed prenatal decisions. Data, collected from three genetic centres in England and Wales from August 1986 to July 1990, are used to describe trends in demand for DNA testing, the impact of DNA tests on carrier risk assessment, and the use of DNA tests in relation to pregnancy outcome. Altogether the data include 23,388 subjects and 681 pregnancies in 8738 families divided into five cohorts by year of entry and referral. The most frequent gene disorders referred to the genetic centres are currently being tested or will soon be tested. For these disorders the initial high level of activity has declined and may have reached steady state. Demand for DNA services is high for cystic fibrosis and Duchenne muscular dystrophy, intermediate for Huntington's disease, and low for adult polycystic kidney disease, phenylketonuria and tuberous sclerosis. Based on these findings we suggest that demand for DNA tests will be high in serious, untreatable and slow progressing conditions with early onset; intermediate for conditions affecting intellect and neurological integrity with later onset; and low for treatable, late-onset conditions, or those for which there is evidence of heterogeneity, and variable penetrance. It would be helpful to assess the extent to which this view of demand is confirmed when the new disorders being DNA tested are considered and for the pattern of activity of DNA testing for some types of cancer. Since no DNA centre could offer a fully comprehensive testing service, it is recommended that a structure is created to audit overall activity, assist in policy formulation, and influence supraregional service organisation, in order that the spread of DNA services be planned as effectively as possible. This structure would facilitate monitoring of the evolution of contract specifications agreed by commissioners and providers on a regional basis.

A methodology for simulating the impact of DNA-probe services on the outcomes of pregnancies

For certain single-gene disorders, DNA probes allow individuals to make more informed decisions about family size and the outcomes of pregnancies. They may also have important psychological effects. We present a method of assessing their impact on the outcomes of pregnancy. We conclude that the traditional approach, which focuses solely on the potential of prenatal diagnostic services to reduce affected births, is limited. It neglects the potential of such services to promote an increase in unaffected births by reducing the number of unnecessary terminations.

UK clinicians' knowledge of and attitudes to the prenatal diagnosis of single gene disorders

Postal questionnaires were sent to 308 clinicians in the UK (general practitioners, obstetricians, clinical geneticists, neurologists, paediatricians, and paediatric neurologists) to assess their knowledge of, and attitudes to, the prenatal diagnosis of three common single gene disorders, Huntington's disease (HD), cystic fibrosis (CF), and Duchenne muscular dystrophy (DMD). Replies received numbered 213, a response rate of 69%. Overall, 95% of responding clinicians thought that offering prenatal diagnosis for the three test conditions was often or always appropriate. There was a correlation between the clinicians' estimates of life expectancy and their willingness to offer prenatal diagnosis (p less than 0.01). Among the non-geneticists questioned, fewer than 50% of general practitioners answered correctly regarding the availability of prenatal tests.