genetic screening

• • carrier testing is offered to individuals with a history of genetic disorders in their family
  • it can show whether people who have no symptoms carry the allele for particular disorders, such as cystic fibrosis
  • couples can be tested prior to having children to determine the probability of future children inheriting the disorder
• benefits of identification of carriers

  • families can make informed decisions before having children
  • women can decide whether to have prenatal testing during pregnancy
• preimplantation genetic diagnosis

  • IVF is a type of fertility treatment during which fertilisation is carried out in a lab; the embryos produced in this way can be implanted into the uterus to develop into a foetus
  • PGD involves analysis of the DNA of an embryo prior to implanting it into the uterus, it can be obtained by taking cell samples from embryos during IVF
• benefits of preimplantation genetic diagnosis

  • reduces chances of having a baby with a genetic disorder
  • avoids abortion as it is carried out before implantation of the embryo
• prenatal testing: offered to pregnant women with a family history of genetic disorders

  • involves testing the foetus for genetic diseases
  • DNA can be obtained by chorionic villus sampling or amniocentesis of embryos and foetuses in the uterus
• chorionic villus sampling

  • involves removing and testing a small sample of cells from the placenta using a fine needle
  • the cells contain foetal DNA which can be analysed for genetic disorders, allowing parents to make informed decisions about the pregnancy and foetus
  • carried out at around 11-14 weeks of pregnancy
  • process has a 1-2% risk of miscarriage
• amniocentesis

  • involves removing and testing a small sample of cells from amniotic fluid using a fine needle
  • amniotic fluid is the fluid that surrounds the foetus within the uterus
  • the fluid contains foetal cells which contain DNA to be analysed
  • it is carried out at around 15-20 weeks of pregnancy
  • the procedure has a 1% risk of miscarriage
• benefits of prenatal testing

  • tests allow parents to make informed decisions
  • results can help parents prepare for the future care of the child including medical treatment
• genetic counsellors help future parents with any questions discussing

  • probability of the couple having a child with a genetic disorder
  • termination of the pregnancy
  • therapeutic treatments possible for the child
  • financial implications of having the child
  • effect on existing siblings
  • ethical issues
• concerns for identification of carriers

  • finding out you are a carrier can cause emotional stress and upset
  • it may impact your ability to find a partner
  • other genetic disorders may be identified
  • employers and insurance companies may use the data against an individual
  • tests are not always 100% accurate; false positives or negatives may be given
• concerns for preimplantation genetic diagnosis

  • concerns it could lead to 'designer babies' where parents select embryos with certain traits such as eye colour or sex
  • false results could lead to inaccurate info and poor decisions being made about the fate of embryos
• concerns on prenatal testing

  • each procedure brings risk of miscarriage
  • false results could provide inaccurate info and poor decisions being made
  • ethical implications involved if parents decide to abort the foetus