Preimplantation Genetic Diagnosis for alpha thalassemia: experience in Siriraj Hospital.

Objective: Detection of fetal thalassemia using preimplantation genetic diagnosis (PGD) can make a diagnosis before pregnancy so termination of pregnancy in that patient is eliminated. The objective of this study was to develop a single gene polymerase chain reaction (PCR) protocol for PGD of alpha thalassemia in Siriraj Hospital. Methods: A couple with a history of repeated Bart’s hemoglobinopathy in fetus underwent an artificial reproductive technique (ART) process using a standard ovarian stimulation protocol with intracytoplasmic sperm injection (ICSI) to reduce sperm DNA contamination. On day 3 post fertilization, laser biopsy was performed on the cleavage stage embryos to obtain a blastomere for PCR analysis of alpha thalassemia 1 SEA type. Results: 11 embryos from a total of 15 oocytes were biopsied, 2 normal, 1 alpha thal 1 trait and 3 affected embryos were detected. No contamination and allele drop out were detected, but a high PCR failure rate of 5 from 11 total biopsied embryos. Conclusion: PGD for alpha thalassemia was first established in Siriraj Hospital, but the result had a high failure rate so then optimized laboratory techniques were required.