Clinical Management of Lynch Syndrome: Revised Guidelines
Clinical Management of Lynch Syndrome: Revised Guidelines
What is the role of prenatal diagnosis (PND) and preimplantation genetic diagnosis (PGD) in LS?
For some individuals, learning that they have LS may have implications for reproductive decision-making. In some cases, this knowledge impacts on the timing of decisions about having children—for example, because of their desire to have children before pursuing prophylactic salpingo-oophorectomy. In addition, some men and women planning on having children in the future may have concerns about possibly passing the genetic risk of LS-related cancers to their children.
Individuals with LS should be adequately counselled about the risk of transmitting their hereditary predisposition to their future children and regarding their options for PND and PGD, including a complete discussion about the legal, practical and psychological aspects of these decisions and also the availability in various countries.
PND is a technique that is performed in early pregnancy. If the family mutation is detected, abortion can be offered. PGD is a technique that always takes place in conjunction with assisted reproduction (in-vitro fertilisation; IVF). Following a succesful IVF procedure, one to two cells from the blastocyst can be tested for the family mutation. Only those embryos without the relevant mutation are selected for placement in the uterus.
Dewanwala et al recently reported that of patients found to carry a gene mutation associated with LS, 42% would consider using prenatal testing and one in five women would consider having children earlier in order to proceed with prophylactic surgery to reduce their risk of developing gynaecological cancers. In addition, the majority of individuals undergoing genetic testing for LS felt that it would be ethical to offer prenatal genetic testing, either PND or PGD, to those with pathogenic MMR gene mutations. Interestingly, while most of the subjects in their study believed prenatal testing would be ethical, only a minority would consider it themselves. These facts reinforce the idea that decisions regarding childbearing are very personal ones and may be influenced by an individual's personal and family history of cancer.
Cancer geneticists and genetic counsellors should be prepared to discuss the option of PND and assisted reproductive technologies during genetic counselling of individuals with LS who are of childbearing age (grade of recommendation C).
Question No 9
What is the role of prenatal diagnosis (PND) and preimplantation genetic diagnosis (PGD) in LS?
Relevant Literature
For some individuals, learning that they have LS may have implications for reproductive decision-making. In some cases, this knowledge impacts on the timing of decisions about having children—for example, because of their desire to have children before pursuing prophylactic salpingo-oophorectomy. In addition, some men and women planning on having children in the future may have concerns about possibly passing the genetic risk of LS-related cancers to their children.
Individuals with LS should be adequately counselled about the risk of transmitting their hereditary predisposition to their future children and regarding their options for PND and PGD, including a complete discussion about the legal, practical and psychological aspects of these decisions and also the availability in various countries.
PND is a technique that is performed in early pregnancy. If the family mutation is detected, abortion can be offered. PGD is a technique that always takes place in conjunction with assisted reproduction (in-vitro fertilisation; IVF). Following a succesful IVF procedure, one to two cells from the blastocyst can be tested for the family mutation. Only those embryos without the relevant mutation are selected for placement in the uterus.
Dewanwala et al recently reported that of patients found to carry a gene mutation associated with LS, 42% would consider using prenatal testing and one in five women would consider having children earlier in order to proceed with prophylactic surgery to reduce their risk of developing gynaecological cancers. In addition, the majority of individuals undergoing genetic testing for LS felt that it would be ethical to offer prenatal genetic testing, either PND or PGD, to those with pathogenic MMR gene mutations. Interestingly, while most of the subjects in their study believed prenatal testing would be ethical, only a minority would consider it themselves. These facts reinforce the idea that decisions regarding childbearing are very personal ones and may be influenced by an individual's personal and family history of cancer.
Conclusion and Recommendation
Cancer geneticists and genetic counsellors should be prepared to discuss the option of PND and assisted reproductive technologies during genetic counselling of individuals with LS who are of childbearing age (grade of recommendation C).
