Proof of principle and first cases using preimplantation genetic haplotyping--a paradigm shift for embryo diagnosis.
Preimplantation genetic haplotyping (PGH) proof-of-principle was demonstrated by multiple displacement amplification (MDA) of single buccal cells from a female donor and genotyping using 12 polymorphic markers within the dystrophin gene; the known paternal genotype enabled identification of the paternal haplotype in the MDA products despite 27% allele dropout. MDA amplified DNA from 49 single human blastomeres with 100% success. The MDA products were genotyped using a total of 57 polymorphic markers for chromosomes 1, 7, 13, 18, 21, X and Y; 72% of alleles amplified providing results at 90% of the loci tested. A PGH cycle was carried out for Duchenne muscular dystrophy. One embryo was biopsied: PGH showed a non-carrier female, which was transferred with no resulting pregnancy. A PGH cycle was carried out for cystic fibrosis. Seven embryos were biopsied and PGH allowed the exclusion of 2 affected embryos; a carrier and a non-carrier embryo were transferred resulting in an on-going twin pregnancy. PGH represents a paradigm shift in embryo diagnosis, as one panel of markers can be used for all carriers of the same monogenic disease, bypassing the need for development of mutation-specific tests, and widening the scope and availability of preimplantation genetic testing.
Renwick
Pamela J
PJ
Genetics Centre, Guy's and St Thomas' NHS Foundation Trust, London SE1 9RT, UK. pamela.renwick@gstt.nhs.ac.uk
Trussler
Jane
J
Ostad-Saffari
Elham
E
Fassihi
Hiva
H
Black
Cheryl
C
Braude
Peter
P
Ogilvie
Caroline Mackie
CM
Abbs
Stephen
S
D000328:Adult; D000483:Alleles; D001483:Base Sequence; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005819:Genetic Markers; D006239:Haplotypes; D006579:Heterozygote; D006801:Humans; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000175:diagnosis* / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques; D010375:Pedigree; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic; D011247:Pregnancy; D019836:Preimplantation Diagnosis / Q000379:methods*; D027724:Reproductive Techniques, Assisted
D017931:DNA Primers; D005819:Genetic Markers