Live birth following the first mutation specific pre-implantation genetic diagnosis for haemophilia A.
Haemophilia A is an X-linked, recessive, inherited bleeding disorder which affects 1 in 5000 males born worldwide. It is caused by mutations in the FactorVIII (F8) gene on chromosome Xq28. We describe for the first time two mutation specific, single cell protocols for pre-implantation genetic diagnosis (PGD) of haemophilia. A that enable the selection of both male and female unaffected embryos. This approach offers an alternative to sexing, frequently used for X-linked disorders, that results in the discarding of all male embryos including the 50% that would have been normal. Two families with a history of severe haemophilia. A requested carrier diagnosis and subsequently proceeded to PGD. The mutation in family 1 is a single nucleotide substitution c.5953C > T, R1966X in exon 18 and in family 2, c.5122C > T, R1689C in exon 14 of the F8 gene. Amplification efficiency was compared between distilled water and SDS/proteinase K cell lysis (98.0%, 96/98 and 80%, 112/140 respectively) using 238 single lymphocytes. Blastomeres from spare IVF cleavage-stage embryos donated for research showed amplification efficiencies of 83.3% (45/54) for the R1966X and 92.9% (13/14) for the R1689C mutations. The rate of allele dropout (ADO) on heterozygous lymphocytes was 1.1% (1/93) for R1966X and 5.94% (6/101) for R1689C mutations. A single PGD treatment cycle for family 1 resulted in two embryos for transfer but these failed to implant. However, with family 2, two embryos were transferred to the uterus on day 4 resulting in a successful singleton pregnancy and subsequent live birth of a normal non-carrier female.
Haemostasis and Thrombosis, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK. katerina.michaelides@csc.mrc.ac.uk
Katerina
K
Michaelides
Edward G D
EG
Tuddenham
Cathy
C
Turner
Ben
B
Lavender
Stuart A
SA
Lavery
D000328:Adult; D004252:DNA Mutational Analysis; D004624:Embryo Transfer; D005169:Factor VIII / Q000235:genetics*; D005192:Family Health; D005260:Female; D006467:Hemophilia A / Q000175:diagnosis*; D006801:Humans; D050498:Live Birth; D009154:Mutation; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D019836:Preimplantation Diagnosis
D005169:Factor VIII