Designer baby

A designer baby is a baby whose genetic makeup has been selected or altered, often to include a particular gene or to remove genes associated with disease. This process usually involves analysing human embryos to identify genes associated with disease, and selecting embryos which have the desired genetic makeup - a process known as pre-implantation genetic diagnosis. Other potential methods by which a baby's genetic information can be altered involve directly editing the genome - a person's genetic code - before birth. This process is not routinely performed and only one instance of this is known to have occurred as of 2019, where Chinese twins Lulu and Nana were edited as embryos, causing widespread criticism. A designer baby is a baby whose genetic makeup has been selected or altered, often to include a particular gene or to remove genes associated with disease. This process usually involves analysing human embryos to identify genes associated with disease, and selecting embryos which have the desired genetic makeup - a process known as pre-implantation genetic diagnosis. Other potential methods by which a baby's genetic information can be altered involve directly editing the genome - a person's genetic code - before birth. This process is not routinely performed and only one instance of this is known to have occurred as of 2019, where Chinese twins Lulu and Nana were edited as embryos, causing widespread criticism. Genetically altered embryos can be achieved by introducing the desired genetic material into the embryo itself, or into the sperm and/or egg cells of the parents - either by delivering the desired genes directly into the cell or using gene editing technology. This process is known as germline engineering and performing this on embryos which will be brought to term is not typically permitted by law. Editing embryos in this manner means that the genetic changes can be carried down to future generations, and since the technology concerns editing the genes of an unborn baby, it is considered controversial and is subject to ethical debate. While some scientists condone the use of this technology to treat disease, some have raised concerns that this could be translated into using the technology for cosmetic means and enhancement of human traits, with implications for the wider society. Pre-implantation genetic diagnosis (PGD or PIGD) is a procedure in which embryos are screened prior to implantation. The technique is used alongside in vitro fertilisation (IVF) to obtain embryos for evaluation of the genome – alternatively, ovocytes can be screened prior to fertilisation. The technique was first used in 1989. PGD is used primarily to select embryos for implantation in the case of possible genetic defects, allowing identification of mutated or disease-related alleles and selection against them. It is especially useful in embryos from parents where one or both carry a heritable disease. PGD can also be used to select for embryos of a certain sex, most commonly when a disease is more strongly associated with one sex than the other (as is the case for X-linked disorders which are more common in males, such as haemophilia). Infants born with traits selected following PGD are sometimes considered to be designer babies. One application of PGD is the selection of ‘saviour siblings’, children who are born to provide a transplant (of an organ or group of cells) to a sibling with a usually life-threatening disease. Saviour siblings are conceived through IVF and then screened using PGD to analyse genetic similarity to the child needing a transplant, in order to reduce the risk of rejection. Embryos for PGD are obtained from IVF procedures in which the oocyte is artificially fertilised by sperm. Oocytes from the woman are harvested following controlled ovarian hyperstimulation (COH), which involves fertility treatments to induce production of multiple oocytes. After harvesting the oocytes, they are fertilised in vitro, either during incubation with multiple sperm cells in culture, or via intracytoplasmic sperm injection (ICSI), where sperm is directly injected into the oocyte. The resulting embryos are usually cultured for 3-6 days, allowing them to reach the blastomere or blastocyst stage.