The preimplantation genetic screening (PGS) is an assisted reproductive technique which enables us to study the genetic and chromosomal alterations in embryos before their implantation, in order to breed healthy, inherited diseases-free babies.
This technique requires an In Vitro Fecundation (IVF) done with an Intracytoplasmic Sperm Injection (ICSI), in order to be able to use the embryos in our laboratory.
In order to study their genetic material, we extract a cell from each of the embryos and we analyse them to discard any which has genetic alterations though molecular genetic techniques. Thus, we only select healthy embryos to transfert to the uterus.
Preimplantation genetic screening cases
Preimplantation genetic screening is recommended in the following cases:
- Structural and numerical chromosomal alteratons, tied or not to the sex chromosomes that could be transmitted to the offspring.
- Elderly women.
- Repeated abortions.
- Implantation failures after several attempts of IVF.
- Alterations during the spermatozoons meiosis.
- Couples who are carriers of sex-linked diseases.
- Couples who have karyotype alterations (translocations, inversions…).
- Avoiding the spread of monogenic diseases.
For couples who did a chromosomal study, the molecular cytogenetic diagnosis allows us to identify normal or balanced embryos with the chromosomes included in the study.
For couples who did a PGS and were given as a result a monogenic disease, the molecular diagnosis allows us to identify which embryos are genetically normal and which are affected by the disease.
Detectable diseases and disorders through genetical screening
Following the highlights of the European Society of Human Reproduction and Embryology (ESHRE), there are over 150 monogenic diseases that can detected through preimplantation screening, such as:
- Cystic Fibrosis.
- Duchenne and Becker Muscular Dystrophy.
- Fragile X Syndrome.
- Fanconi Anemia.
- Bulbar and Spinal Muscular Atrofy.
- Marfan Syndrome.
- Sickle-Cell Disease.
- Neurofibromatosis type I and II.
- Menkes Syndrome.