Saving Henry by Laurie Strongin Read Free Book Online Page A

transfer. PGD would enable us to identify and implant an artificially conceived embryo that was not only healthy, but who could also be Henry’s savior. By collecting this healthy baby’s umbilical cord blood at birth and transplanting the stem cells to Henry, our baby could cure Henry’s blood disease.
    â€œPreimplantation genetic diagnosis.” Three words that, strung together, are easily passed over like so many medical terms that can be mistaken for a foreign language. Individually the words are powerful. “Preimplantation.” Before implantation. Before becoming my baby. Insurance against ever having to consider abortion. “Genetic.” Inherited. In this case, a disease best expelled from our gene pool.“Diagnosis.” Certainty. A guarantee that Fanconi anemia could never again threaten to destroy one of my babies. Together these words formed a profound source of hope and dominated our life. And the shorthand, PGD, became part of our family vocabulary.
    Dr. Hughes had used PGD in the past to screen embryos for fatal childhood diseases like sickle cell anemia and cystic fibrosis, enabling parents to know at the outset that their babies would not be born with a disease. But neither he—nor anyone else in the world—had ever used PGD to find a perfect HLA match, from whom umbilical cord stem cells could be harvested and thus save a sibling.
    â€œIn other words, we’d be the first?” Allen asked me.
    â€œApparently so.”
    â€œWait. Let me get this straight. We’d be the first , ever , anywhere ?”
    Preimplantation genetic diagnosis involves the biopsy of one or two cells from an eight-cell embryo, typically on the third day following egg retrieval, as part of an in vitro fertilization cycle. The biopsy is performed in a laboratory by making an opening in the outer “shell” of the embryo with a micropipette. One or two cells are extracted through this opening in an extremely delicate procedure. Once the embryo has been biopsied, it takes about forty-eight hours for the genetic testing to be completed before the embryo, which remains in a lab and continues to develop to the blastocyst stage, must be transferred to the woman’s uterus to be able to produce a viable pregnancy.
    The extracted cell(s) are analyzed to determine the genetic composition of the embryo. These tests can determine the presence of Down’s syndrome or trisomy 21, among other chromosomal abnormalities. Testing can also be done for couples known to carry diseases caused by a single gene abnormality, such as FA. To determine whether an embryo has FA, a technique known as a polymerase chain reaction (PCR) is used to replicate the targeted gene. These copies are examined for evidence of a particular DNA sequence that reveals the presence or absence of FA. The results of preimplantation genetic diagnosis are used to inform the selection of embryos for transfer to a woman’s uterus, enabling her to begin her pregnancy with the knowledge that her baby will not possess the life-threatening childhood disease.
    It has been more than a decade since physicians like Dr. Hughes have used PGD for disease prevention. Today, approximately one thousand babies have been born using this technique. But in 1996, when we began talking with Drs. Auerbach and Hughes, PGD had never been used to test for HLA type or any other trait that was not a matter of survival to the embryo being tested.
    Dr. Hughes had agreed to offer PGD with HLA typing to FA families who met several very specific criteria. First of all, the mother had to be under thirty-five years old; at the time I was thirty-one. Younger mothers typically produce more eggs in the process of in vitro fertilization and therefore have a greater likelihood of success. They also have a lower risk of producing eggs with abnormal chromosomes. In addition, Dr. Hughes would work only with families who had already expressed an interest in