GENETİCS (PGD)

On the third day after fertilization (on an 8-cell embryo) a hole is made in the membrane of the embryo (using laser assisted hatching) and two cells called blastomeres are removed. These blastomeres are placed in different petri dish and sent to genetic laboratories for screening. The blastomeres should be taken out very carefully so as not to damage and kill the embryo.

Since genetic analysis is an expensive procedure which carries risks to the embryos, it should only be performed on patients at risk of passing on their genetic illness to their offspring. To perform PGD, genetic history of both partners should be taken, both partners should be screened for genetic diseases, and both partners should look into their risks of carrying a genetic disease. It should be noted that very few diseases are currently detected with PGD due to limited working materials and the fact that only two blastomeres can be removed for analysis. Since very few of the many genetic diseases can be screened for, a healthy blastomere does not guarantee a healthy baby.

Since the biopsies are very limited, the technique should yield accurate, reliable and fast results. The laboratory personnel should also be qualified for genetic analysis. The two most widely used techniques for PGD are FISH and PCR which use special marker techniques.

PGD is mostly used for the screening of Thalassemia which is a very common genetic disease in the Mediterranean region. If both partners are carriers of the disease, the risks of the child having the disease are very high. With PGD, blastomeres are analyzed and only healthy embryos are transferred to the woman's uterus.

Diseases diagnosed with PGD:

 Thalassemia

 X-linked diseases (sex-linked),

 Heamophilia,

 Muscular distrophy 

 Trisomies (Down, Klinefelter etc.)

Sickle-cell anemia.