Pre-implantation Genetic Diagnosis of Thalassemias

• Main Author: Wirawit Piyamongkol
• Format: Article
• Language: English
• Published: The Royal Thai College of Obstetricians and Gynaecologists 2018-03-01
• Series: Thai Journal of Obstetrics and Gynaecology
• Subjects: Embryo selection; hemoglobinopathy; multiplex fluorescent polymerase chain reaction (PCR); pre-implantation genetic diagnosis (PGD)
• Online Access: https://tci-thaijo.org/index.php/tjog/article/view/117391/92852
• ISSN: 0857-6084; 0857-6084

Beta-Thalassemia major, beta-thalassemia-Hb E disease and Hb Bart’s disease are severe hereditary anemia which are prevalent in Thailand and neighborhood countries. Thalassemia syndromes and hemoglobinopathy cost significant health and economic burden and sometimes maternal morbidity and mortality. The present strategy to reduce new cases is population screening, prenatal genetic diagnosis (PND) and the option for termination of affected pregnancy (TOP) following thoroughly genetic counselling. The advances of reproductive technology and molecular genetics facilitate genetic testing of the embryos prior to transfer into the womb, therefore, embryo selection is possible. Pre-implantation genetic diagnosis (PGD) consists of sampling techniques from the embryos and molecular genetic analysis techniques. Polar body biopsy, cleavage stage embryo biopsy or blastocyst biopsy can be used for sampling DNA material from the embryos. Polymerase chain reaction (PCR) is employed for the analysis of thalassemia mutations. PGD is an alternative to the traditional PND, providing the couples at risk of having severe thalassemia babies an opportunity to get pregnant with a healthy one without the need for TOP. Since 2004, a total of 64 PGD cycles have been performed at the Department of Obstetrics and Gynaecology, Faculty of Medicine, Chiang Mai University, including 37 alpha-thalassemia, 5 beta-thalassemia and 22 beta-thalassemia-Hb E disease, giving rise to 24 healthy pregnancies (27 babies).