The case of Re Leo  FamCA involved an application to the court by the parents of a minor, aged 16 ½ who has been diagnosed with gender dysphoria. The applicants sought that the court declare that the child is competent to authorise his own treatment for stage 2 administration of testosterone and for male chest reconstruction surgery. The child had been born a female and had identified as a male gender from a very early age. The application was supported by the child’s treating doctors, Independent Children’s Lawyer and the respondent. The Judge in the case found that the 16 ½ child had met the Gillick criteria of competence to make an informed decision (capacity to decide) about a proposed medical procedure.
What is the Gillick criteria of competence?
Determining whether a minor has the competence to consent to a medical procedure can be a complex area. A minor is regarded as being capable of giving informed consent when he or she achieves sufficient understanding and intelligence to enable him or her to understand what is being proposed. This test of competence to consent comes from the English case of Gillick v West Norfolk AHA (1986) 1 AC 150. Lord Scarman’s the test for competence is widely used as the Gillick competency test:
““As a matter of Law the parental right to determine whether or not their minor child below the age of sixteen will have medical treatment terminates if and when the child achieves sufficient understanding and intelligence to understand fully what is proposed.”
The UK decision has been given approval by the High Court in Australia in Marion’s case Department of Health and Community Services v JWB and SWB  HCA 15; (1992) 175 CLR 215