Preimplantation Genetic Diagnosis (PGD)
PGD is an advanced single-gene diagnostic technique that allows screening of embryos for any specific hereditary diseases especially for people with a family history of a single-gene disorder to reduce the risk of embryos being affected by that condition. Some of the disorders that can be tested through PGD are Thalassemia, cystic fibroids, BRCA1/BRCA2 which can lead to hereditary breast and/or ovarian cancer.
This test can be carried out either on the 3rd or 5th day of embryo development during the IVF program. After the testing, only the healthy embryos that do not contain any genetic conditions are transferred back to the uterus for implantation.
Screening for hereditary diseases can be done through:
This is mostly recommended for people with a family history of genetic disease or when a genetic disease has been identified. When this is detected, a PGD is completed during IVF cycle to prevent passing on the genetic disease to the child.
This on the other hand, is used to screen for unidentified hereditary disease or polygenic disease which usually involves interaction of two or more genes. Next generation sequencing analyses a significant number of genes at once unlike current sequencing techniques that analyse one gene or small groups of related genes at a time.