Pre-Implantation Genetic Diagnostics PGD/PGS
The pre-implantation genetic analysis is a set of examinations which can help as reveal genetic abnormalities of embryo before it is transferred to the mother.
The pre-implantation genetic analysis can be conducted in two ways:
- Pre-implantation genetic diagnostics (PGD) performed in order to disprove potential genetic damage known, for instance, with the parents
- Pre-implantation genetic screening (PGS) which checks for abnormal numbers of chromosomes (aneuploidy).
The pre-implantation genetic screening and pre-implantation diagnostics are collectively identified as PGD (pre-implantation genetic diagnostics).
Why to conduct PGD?
A number of severe genetic diseases of a person are caused by changes in numbers or structure of chromosomes. Inborn chromosome disorders can be inherited from parents or newly created as a result of mutations affecting the sex cells (gametes) or early stages of embryo development.
The specialized studies indicate that these inborn disorders of chromosomes may constitute a major cause of infertility, cause repeated abortions or birth of a child with severe inborn disorders.
The most widely known disease is Down syndrome caused by excessive chromosome 21. It has also been proven that the share of genetically abnormal embryos increases proportionally with the woman’s age.
What can be examined using PGD/PGS?
Most frequently, abnormalities in numbers of chromosomes are examined, which reduces the risk of abortion or birth of a child with severe inborn defect. It also examines disorders of the genes on chromosomes. A gene is a heredity information, based on which the form and function of the organism is formed. A gene failure may cause disease.