PGT or Pre Implantation Genetic Diagnosis is a technique for profiling of the embryos in patients with pre existing familial or hereditary diseases. In this procedure a single cell is biopsied from a blastocyst and sent for genetic evaluation to check for the presence of any genetic or chromosomal abnormality in the blastocyst. Only those blastocyst are considered for transfer in which there are no genetic irregularities and hence a disease free baby can be brought to the world .