At Gennima, we apply the techniques of Preimplantation Genetic Diagnosis (PGD) and Preimplantation Genetic Screening (PGS), combining molecular genetics with assisted reproduction.
Preimplantation genetic diagnosis, PGD
When one or both parents carry a gene with a mutation, the test is carried out to verify whether the mutation in question has been transmitted to the embryo as well.
Preimplantation genetic screening, PGS
When the parents have a normal karyotype (chromosomes) and embryos are checked concerning the number of chromosomes.
With preimplantation genetic screening, embryos are screened before embryo transfer and pregnancy achievement, regarding the following:
• Hereditary diseases detected in one (1) gene, such as thalassemia or cystic fibrosis
• Abnormalities in chromosome number (e.g. Down syndrome) and structure.
• Selection of embryo gender in case of gender - linked diseases, such as fragile X chromosome, hemophilia or Duchenne muscular dystrophy.
Preimplantation genetic diagnosis has been developed for couples who carry a “defective” gene and run an increased risk of giving birth to children with severe genetic diseases, such as thalassemia or cystic fibrosis, with no coexisting infertility of the couple. In those cases, the man and woman are carriers of the disease, i.e. they are perfectly healthy themselves, but one of their 2 genes is “sick”. However, when 2 carriers of one such disease want to have a child, the latter will possibly have the disease, as she/ he may have inherited the “sick” gene from both parents. Namely, chances of having a child with thalassemia or cystic fibrosis reach 1 out of 4 for each pregnancy.
In the past, the only solution for parents with this problem was to diagnose the disease during pregnancy (that is, when the embryo was all grown up) and terminate the pregnancy. As it can be understood, terminating a pregnancy is a very unpleasant choice. With PGD this is no longer necessary, as embryos are screened before embryo transfer. For that reason, PGD is only possible during an IVF cycle.