Preimplantation Genetic Diagnosis of Androgen Resistance Syndrome Caused by Mutation on the AR Gene in Vietnam

Trieu Tien Sang,1 Khoa Tran Van,1 Nguyen Thanh Tung,2 Phong Nguyen Van,1 Phuong Tran Hoang3 1Department of Biology and Medical Genetics, Vietnam Military Medical University, Hanoi, 10000, Vietnam; 2Military Institute of Clinical Embryology and Histology, Vietnam Military Medical University, Hanoi, 10000, Vietnam; 3Department of Oncology, 108 Military Central Hospital, Hanoi, 10000, VietnamCorrespondence: Trieu Tien Sang, Vietnam Military Medical University, Hanoi, 10000, Vietnam, Email trieusangk83@yahoo.com.vnBackground: Androgen resistance syndrome or androgen insensitivity syndrome (AIS – Androgen Insensitivity Syndrome, OMIM 300068) is an X-linked recessive genetic syndrome causing disorders of sexual development in males. This disease is caused by mutations in the AR gene located on the X chromosome, which encodes the protein that structures the androgen receptor, with the role of receiving androgens. Mutation of the AR gene causes complete or partial loss of androgen receptor function, thereby androgen not being obtained and exerting its effect on target organs, resulting in abnormalities of the male reproductive system due to this organ system, differentiating towards feminization under the influence of estrogen. Disease prevention can be achieved by using pre-implantation genetic diagnosis, which enables couples carrying the mutation to have healthy offspring.Aim: To carry out preimplantation genetic diagnosis of androgen resistance syndrome.Methods: Sanger sequencing was used to detect the mutation in the blood samples of the couple, their son, and 01 embryo that were biopsied on the fifth day based on the findings of next-generation sequencing (NGS) of the affected son. We combined Sanger sequencing and linkage analysis using short tandem repeats (STR) to provide diagnostic results.Results: We performed preimplantation genetic diagnosis for AIS on an embryo from a couple who had previously had an affected son. Consequently, one healthy embryo was diagnosed without the variant NM_000044: c.796del (p.Asp266IlefsTer30).Conclusion: We report on a novel variant (NM_000044: c.796del (p.Asp266IlefsTer30)) in the AR gene discovered in Vietnam. The developed protocol was helpful for the preimplantation genetic diagnosis process to help families with the monogenic disease of AIS but wish to have healthy children.Keywords: androgen insensitivity syndrome, AIS, AR gene, preimplantation genetic diagnosis, short tandem repeats, STR