[Individual genetic counseling and collective screening strategies in particular at-risk populations]

Carrier screening for recessive disorders together with prenatal diagnosis offered in at risk pregnancies can achieve efficient prevention of genetic diseases occurring with particularly high frequencies in specific populations. In this context, genetic counseling, which should be available to each at risk couple, must be integrated into a more elaborate framework geared towards informing the target population. Dramatically different outcomes of carrier screening programmes implemented in the past illustrate the conditions for success or failure. The need to target selected ethnic groups accounts for most of the problems encountered: underpriviledged minorities, risk of discrimination and, most importantly, cultural gaps leading to refusal of prenatal diagnosis and/or of selective abortion. In order to achieve prevention through screening programmes, the tests should therefore be preceded by dissemination of adequate information into the target population, followed by genetic counseling for at risk couples, addressing cultural differences. Prenatal diagnosis should always be proposed, but never imposed on these couples. Finally, these screening programmes must be underpinned by comprehensive subsidies covering not only the tests but also education and counseling that should always be provided with the tests. In terms of public health, this is the price for a cost-effective genetic screening programme.