History
In 1967, Robert Edwards and Richard Gardner reported the successful sexing of rabbit blastocysts, setting the first steps towards PGD. It was not until the 1980s that human IVF was fully developed, which coincided with the breakthrough of the highly sensitive polymerase chain reaction (PCR) technology. Handyside and collaborators' first successful attempts at testing were in October 1989 with the first births in 1990 though the preliminary experiments had been published some years earlier. In these first cases, PCR was used for sex determination for patients carrying X-linked diseases.
PGD is available for a large number of monogenic disorders —that is, disorders due to a single gene only (autosomal recessive, autosomal dominant or X-linked)— or of chromosomal structural aberrations (such as a balanced translocation). PGD helps these couples identify embryos carrying a genetic disease or a chromosome abnormality, thus avoiding diseased offspring. The most frequently diagnosed autosomal recessive disorders are cystic fibrosis, Beta-thalassemia, sickle cell disease and spinal muscular atrophy type 1. The most common dominant diseases are myotonic dystrophy, Huntington's disease and Charcot-Marie-Tooth disease; and in the case of the X-linked diseases, most of the cycles are performed for fragile X syndrome, haemophilia A and Duchenne muscular dystrophy. Though it is quite infrequent, some centers report PGD for mitochondrial disorders or two indications simultaneously.
PGD is also now being performed in a disease called Hereditary multiple exostoses (MHE/MO/HME).
In addition, there are infertile couples who carry an inherited condition and who opt for PGD as it can be easily combined with their IVF treatment.
Read more about this topic: Preimplantation Genetic Diagnosis
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