Preimplantation Genetic Diagnosis and Screening at Bridge

		Professor Alan H Handyside MA PhD Consultant in Pre-implantation Genetics Pioneered Preimplantation Genetic Diagnosis (PGD) with Professor Lord Robert Winston at Hammersmith Hospital, London in the late eighties. Co-founder and first Chairman of the European Society for Human Reproduction and Embryology PGD Consortium. Professor of Developmental Biology, School of Biology, University of Leeds.

Bridge has been running a Preimplantation Genetic Diagnosis programme since January 2004. Licensed by the Human Fertilisation and Embryology Authority (HFEA), this is one of the most comprehensive services available anywhere in Europe and is directed by Professor Alan Handyside, Consultant in Pre-implantation Genetics and Dr Alan Thornhill, Scientific Director of Bridge.

Single Gene Defects or HLA Matching

To develop a test for a single gene defect (e.g. Cystic Fibrosis, Marfan Syndrome, Sickle Cell) and HLA matching, we use a technique that combines genetic linkage testing with traditional mutation analysis. Test development can take up to 6 months and will require blood samples from you and your partner and, possibly, additional family members. When test development has been completed, testing of the embryo can take place.

Chromosome Imbalance in Translocation Carriers

For test development for chromosomal rearrangements, we use our own UK-based laboratory, Bridge Genoma. Most test development takes from 4-8 weeks and will require blood samples from you and your partner and, possibly, additional family members. When test development has been completed, testing of the embryo can take place. If a test was developed for you more than 6 months ago, it will need to be validated prior to starting your fertility treatment. For men with a chromosome rearrangement, a sperm translocation test is recommended to identify the proportion of sperm present with an unbalanced form of the translocation in a semen sample.

Aneuploidy

Aneuploidy screening is a procedure that screens for the number of chromosomes present in an embryo. By screening embryos and only transferring those with no identifiable genetic abnormalities, we aim to reduce the risk of having a child with a chromosome abnormality, reduce the risk of miscarriage and provide useful diagnostic information regarding the likelihood of success through IVF treatment.

Preimplantation Genetic Diagnosis (PGD) - under reconstruction