PGD, Preimplantation genetic diagnosis, can help identify many genetic abnormalities before the embryo is transferred to the uterus. Genetic errors arise from deletions or insertions of genetic material, abnormal numbers of whole chromosomes or genes, and even from misplacement of a single base in the DNA sequence. Genetic abnormalities can range from relatively harmless to severe: from vitamin deficiencies and food allergies to cancer, birth defects and infant mortality.

PGD, and other significant advances in technology, have enabled researchers to trace many disorders and diseases to their roots in the genetic code. Chromosome stretches, or even isolated genes, can now be used as markers to identify individuals at risk for certain illnesses.

PGD has become an effective screening procedure for many genetic diseases and is also used for gender selection. The ability to recognize genetic warning signs is rapidly becoming the most effective tool for prevention, diagnosis, and treatment of genetically based disorders. An estimated 60 percent of all naturally occurring reproductive losses in pregnancies are associated with chromosomal abnormalities in the embryo.

A normal embryo has 22 pairs of chromosomes called autosomes and 1 pair of sex chromosomes (XX or XY). Embryos that do not carry the normal pair of each chromosome are called aneuploids. Those that contain three copies of a particular chromosome (Trisomy) are the cause of some genetic disorders such as Down's syndrome (Trisomy 21). There are other less common trisomies of chromosomes 13, 16, 18 and 22. Embryos that contain only one copy of a chromosome (Monosomy) are by and large nonviable.

PGD and genetic analysis can differentiate abnormal aneuploid embryos, either with monosomy (one missing) or trisomy (an extra one), which are usually normal in appearance. It is not possible to distinguish these morphologically from other embryos. Without PGD analysis, many of these embryos are unknowingly transferred to patients.

HRC is one of the largest providers of assisted reproductive treatments, including PGD, in the US. Both the physicians and staff of HRC are committed to maintaining the highest standard of infertility care in reproductive medicine in terms of moral and ethical practices. Significant experience in infertility treatment and embryo culture, highly skilled medical and laboratory personnel make it possible to offer PGD technology to couples at risk of having a genetically abnormal fetus which can help them avoid the birth of an affected child or having to face the painful decision of a pregnancy termination.

Genetic Diseases that Can be Screened Using PGD

As research continues, new diseases are constantly added to the list of conditions which can be diagnosed using PGD.

• PGD Historical Overview
• PGD Process Detailed Description
• PGD Success Rates
• PGD Gender Selection