Genetic counselling is advice and information given to people about genetic conditions, based on their family history and the results of genetic screening. Counsellors explain complex results clearly and without pressure, so that people can make their own informed decisions.A genetic counsellor may:
• explain the results of a screening test and what they mean
• work out and explain the probability of a person developing a condition or passing an allele on to their children
• explain the options available, such as treatment, preventive measures, or IVF with embryo screening
• give emotional support and refer people to other services.Worked example: two parents are both carriers of the recessive allele for cystic fibrosis (genotype Ff).Ff × Ff → FF : Ff : ff = 1 : 2 : 1 So each child has a 1 in 4 (25%) chance of having cystic fibrosis (ff) and a 1 in 2 (50%) chance of being a carrier (Ff). The counsellor would explain that these chances apply to each pregnancy separately.Example: BRCA1. A woman with a family history of breast cancer is screened and found to carry a BRCA1 allele that greatly increases her risk. A counsellor would explain the size of her risk and her options, such as more frequent mammograms or preventive surgery to remove the breasts (a mastectomy), and whether her relatives might want to be tested.Counselling also raises ethical issues: a result may affect family members who did not choose to be tested, and people may feel pressure over decisions about having children.
• explain the results of a screening test and what they mean
• work out and explain the probability of a person developing a condition or passing an allele on to their children
• explain the options available, such as treatment, preventive measures, or IVF with embryo screening
• give emotional support and refer people to other services.Worked example: two parents are both carriers of the recessive allele for cystic fibrosis (genotype Ff).