One child in every 100 babies born inherits a genetic condition that can often have a devastating impact, not only on a child but also on the family. Detecting if an inherited genetic disease before pregnancy is becoming an increasingly precise science. Preconception testing can identify healthy carriers at genetic risk, whilst preimplantation genetic testing for monogenetic disease (PGT-M also known as PGD) can be offered to couples wishing to avoid the risk of having a child with a genetic disease.
PGT-M (PGD) has revolutionised the prospects of parenthood for couples who are known carriers of, for example, the cystic fibrosis gene mutation. By identifying and transferring those embryos without the mutation, carrier couples can be reassured that their baby will not be affected by a severe genetic condition. This technique provides a valuable alternative to conventional prenatal diagnosis by chorionic villus sampling (CVS) or amniocentesis.
Who is PGT-M (PGD) suitable for?
PGT-M is suitable for people who have a serious genetic condition themselves, or who are carriers of conditions that is currently licensed by the Human Fertilisation and Embryology Authority (HFEA) for PGT-M. The list of PGT-M conditions can be found on the HFEA’s website. The risks for these conditions are usually evident in family history, which is why couples hoping to avoid transmission to a baby are often referred by their family doctors or they refer themselves.
What can PGT-M (PGD) identify?
Most of the disorders that PGT-M (PGD) can prevent are those associated with abnormalities of a single gene or a single chromosome. The most common are Cystic Fibrosis, Beta Thalassaemia and Sickle Cell Anaemia. This testing is also used for rare genetic conditions and presently, the Human Fertilisation and Embryology Authority (HFEA) lists more than 300 single gene defects for which PGT-M (PGD) is approved.
Cystic fibrosis, for example, may be evident in a family. A child born to two carriers of the Cystic Fibrosis genetic alteration will have a one-in-four chance of having the disease. PGT-M (PGD) can test the embryos for evidence of the genetic alteration and ensure that only unaffected embryos are transferred – removing any risk of the baby inheriting the disease.
PGT-M (PGD) requires knowledge of the exact mutation to develop a specific test for its identification in an embryo. This can lead to a wait of many months for a test to be developed before IVF can be started. Professor Alan Handyside, Consultant in Preimplantation Genetics at the LWC, has pioneered a faster version of PGT-M called ‘Karyomapping’ that can test for conditions in a much shorter time frame than conventional PGT-M (PGD). This is the current ‘gold standard’ for preimplantation genetic testing for single gene disorders.
Testing for genetic risk
The London Women’s Clinic uses a comprehensive, focused male and female questionnaire and consultation with a clinician to recognise couples at genetic risk. Following a review of your family history, genetic tests may be recommended and the implications the test for you and your wider family will be carefully explained.
If indicated, we offer:
- Specific genetic tests related to infertility
- Karyotyping (chromosome analysis) to identify any chromosome abnormalities
- Carrier testing for specific genetic diseases based on ethnic background and family history
Meet the embryo screening team
Our dedicated team has over 25 years experience in fertility and genetics
Mr Michel Summers, Consultant in Reproductive Medicine
A graduate of King’s College, Cambridge Mr Summers completed his medical training at the University of Pennsylvania School of Medicine followed by a Clinical Fellowship in Reproductive Endocrinology and Infertility at the Brigham and Women’s Hospital, Harvard Medical School. He is certified by both the American College of Obstetrics and Gynaecology (ACOG) as well as on the GMC Specialist Register as a Consultant in Reproductive Medicine. His special interests include IVF, embryo culture, embryo implantation and preimplantation genetic diagnostics, areas of research in which he has published extensively.
Elena Linara, Senior Embryologist and Quality Lead
Elena has 10 years’ experience within embryology and is qualified in biomedical sciences, prenatal genetics and fetal medicine, and clinical embryology. She is particularly interested in ocyte and embryo vitrification, prenatal genetics, quality management, intrauterine insemination and egg sharing. Before joining the team at LWC she worked as an embryologist, andrologist and a deputy sperm bank manager.