FAQs on Preimplantation Genetic Testing in Los Angeles
Preimplantation genetic testing involves identifying genetic defects within embryos created by in vitro fertilization (IVF). Also called preimplantation genetic diagnosis (PGD), this form of testing is used to prevent diseases that can be passed on to the child.
How is PGD performed?
Preimplantation genetic diagnosis begins with in vitro fertilization, which includes egg retrieval and laboratory-based fertilization. The embryo then divides into eight cells during the next three days.
There are five steps involved with PGD. These include:
1. Removal of 1-2 cells from the embryo.
2. Evaluation of cells to determine problematic gene inheritance.
3. Embryos free of disease and genetic problems are then placed back into the uterus.
4. Attempt of implantation.
5. Freezing additional embryos free of disease and genetic problems for later use.
Who is a candidate for PGD?
Preimplantation genetic testing helps any couple who are at risk for passing genetic conditions on to their children. Candidates for PGD include:
• Women age 35 years and older (eggs have greater chance of abnormalities)
• Carriers of sex-linked genetic disorders, such as hemophilia
• Anyone with chromosomal disorders
• Carriers of single gene disorders, such as cystic fibrosis
• Women who suffer recurrent pregnancy loss
• Couples who have failed other fertility treatments
• Couples in need of human leukocyte antigen (HLA) testing
What are the benefits of preimplantation genetic testing?
PGD offers many benefits. These include:
• PGD can test for over 100 varying genetic disorders.
• PGD allows the couple a chance to have a healthy child.
• The procedure permits couples to pursue biological children.
There are a few disadvantages to preimplantation genetic diagnosis. These include:
• The destruction of an embryo is considered to some people to be destruction of life.
• PGD reduces the chance of conceiving a child with certain genetic diseases, but it does not eliminate the risk altogether. For some couples, further testing is required.
• PGD does not replace prenatal testing.
Which diseases are tested for using PGD?
The following diseases and many others can be detected with preimplantation genetic testing:
• Cystic fibrosis
• Cancer predisposition genes (such as BRCA1)
• Fragile X syndrome
• Duchenne muscular dystrophy
• Huntington’s disease
• Tay-Sach’s disease
• Sickle cell anemia
• Multiple endocrine neoplasia
What else do I need to know about preimplantation genetic diagnosis?
Couples interested in PGD should make an appointment. After the initial consultation, couples meet with a genetic counselor to discuss pertinent medical and family history. Additionally, the doctor evaluates for risk of an inherited disorder. Blood is drawn from the man and the woman to assess for genetic mutations and chromosomal abnormalities. The laboratory must design a protocol for testing the embryos, which takes around 6-8 weeks. Once the PGD protocol is in place, the couple proceeds to undergo IVF.