Adolescent carrier testing in practice: the impact of legal rulings and problems with "gillick competence".

Testing for carrier status for various genetic conditions often takes place during adolescence or young adulthood. This paper aims to add to the discussion of when is the best time to test through an examination of how the law on medical treatment of children appears to be used in practice and how a careful examination of legal rulings might shed light upon best practice in this area. Our focus is on the Gillick ruling (Gillick v West Norfolk and Wisbech Area Health Authority 1986), which dealt with consent and confidentiality with respect to the provision of contraceptive advice to under 16-year-olds, but which has become a general benchmark for consent to medical treatment within UK law. In addition, we draw upon data from a qualitative research study which indicates potential problems with certain practices in respect of the influence of the Gillick ruling on carrier testing procedures. We present evidence that in at least some instances, adolescents have reduced capacity to grasp fully the implications of carrier test results. In the light of our findings we make recommendations for practice concerning the testing of children and young persons.