Pre-implantation Genetics Diagnosis (PGD) for Carriers of Chromosome Rearrangements

Pre-implantation genetic diagnosis (PGD) testing for chromosome rearrangements is carried out by array CGH. This test can be offered to couples requiring tests for the following:

1. Reciprocal translocations
2. Robertsonian translocations
3. Inversions and insertions
4. Deletions and duplications
5. Complex chromosome rearrangements (CCRs)
6. Sexing for an X-linked condition

The material used for testing is material obtained from the trophoblast from blastocyst stage embryos (trophectoderm biopsy). The biopsy is taken on day 5, 6 or 7 post-fertilisation.
Clinical details: 
Pre-implantation genetic diagnosis (PGD) is available to couples that are at risk of having a child with an unbalanced chromosome rearrangement; it can also be used for sexing for a familial X-linked condition (if a mutation is not known).

IVF protocols are used to obtain and fertilise a number of eggs. The fertilised embryos develop for five to seven days and then the trophectoderm layer of each embryo is biopsied to collect approximately ~5-10 cells. The genetic material (DNA) from the cells is tested for the known chromosome rearrangement in the family. Unaffected embryos are then transferred into the uterus, with the aim of establishing a pregnancy unaffected by imbalance for the chromosomes tested or the specified X-linked condition.

The genetics laboratory works closely with the Centre for Pre-implantation Genetic Diagnosis at Guy's and St Thomas' Trust which is the largest and most successful centre in the UK for PGD for chromosome rearrangements and monogenic disorders, with over 700 babies born as a result of this treatment.

Sample type and Volume required: 
Turnaround time: 
3 weeks post embryo biopsy
Storage and transport: 
Transport PGD is not available, patients should be referred to the Guy’s & St Thomas’ Centre for PGD
On application
Pre-Implantation Genetic Diagnosis at Guy's Hospital
Genetics Department
Borough Wing - 7th Floor
Guy's Hospital
Great Maze Pond
London SE1 9RT

For Monogenic Disorders contact Dr Pamela Renwick
T: 020 7188 1667
F: 020 7188 7273

For Chromosome Rearrangements contact Dr Angela Davies or Ms Susan Bint
T: 020 7188 1701
F: 020 71881697
For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 20/10/2017