Preimplantation genetic diagnosis.

Preimplantation genetic diagnosis (PGD) has now been used in human fertility centers for a decade. To this end, diagnostic analysis is conducted on polar bodies or single blastomeres from biopsied embryos before the embryos are transferred, allowing the selection of normal embryos before a pregnancy has been established. Advances in technology available for PGD are described, including fluorescent in situ hybridization (FISH), interphase chromosome conversion, comparative genomic hybridization (CGH), fluorescent polymerase chain reaction (PCR), multiplex PCR, and whole genome amplification. These techniques support the diagnosis of a number of diseases at the single-cell level.