Genetic Risks: The Implications of Embryo Screening


The doctors told the parents: "It's very likely that it won't survive." Birth was induced prematurely in the 21st week, and the child died shortly after delivery.

After they overcame the shock, the Schäfers went to university hospitals and genetic specialists to try to find out what could be done so that they wouldn't have to experience the same thing again. "We were in Munich, Bonn, Lübeck and Wiesbaden," says Jürgen Schäfer. "They all referred us to someone else." If they hadn't found the MGZ, the Schäfers would have gone to Belgium.

Holinski-Feder explains to the Schäfers how PID is done. A fertility center removes oocytes, or immature egg cells, from the woman and artificially inseminates them. On the fifth day of development, a few of the cells that are emerging from the shell are extracted. These cells have the same genetic material as the embryo, but they develop into placenta. The procedure is called trophectoderm biopsy. By examining these cells, the MGZ can determine whether an embryo has inherited certain genetic defects.

"If we don't try this now," says Jürgen Schäfer, "we'll regret it for the rest of our lives."

They walk out of the doctor's office and go to the coat closet. Jürgen Schäfer gets their jackets so that he can help his wife put hers on. Carola Schäfer is sitting in a chair, and her husband sits down next to her. Then she leans her face against his shoulder and begins to cry.

'All We Have Is a Few Cells' Back in her office, Holinski-Feder points to her computer. "All of our PID patients have experience with miscarriages and stillbirths. Either that, or they are living with a severely disabled child at home." If they didn't, she adds, they wouldn't know that they are carriers of genetic defects.

Holinski-Feder will offer the Schäfer family the option of performing an analysis for chromosomal deformity. A procedure called array-CGH diagnostics is used to determine whether the quantity and arrangement of chromosome pairs is normal. This method does not detect other genetic changes, including muscular dystrophy, cystic fibrosis and congenital nephrotic syndrome, the disease Maya Stark has.

"There are more than 16,000 congenital disorders," says Holinski-Feder, "and all we have is a few cells. We're pleased when we can find what we are looking for."

Precisely because PID is only used to search for specific defects, fears that it could be used on a large scale are unfounded, says Holinski-Feder. She notes that only a small percentage of all disabilities can be prevented with the help of the procedure.

About 80 percent of all disabilities occur during or after birth. Of the remaining 20 percent, many are caused by influences during pregnancy, such as alcohol consumption. "Congenital disorders presumably make up less than 10 percent," says Holinski-Feder. And even within that group, she adds, most disorders are attributable to spontaneous gene mutations. "Despite PID, fate still plays an important role." An estimated 200 to 300 affected couples a year will take advantage of PID.

Artificial insemination will cost the Schäfer family roughly €5,000 ($6,770), and the genetic analysis at the MGZ will cost about the same. They'll have to pay out of pocket, because the German health insurance system doesn't cover these costs at the moment.

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