AB162. Genes variation in three families of Vietnamese dioxin victim

Abstract: Dioxins are a class of chemical contaminants that are formed during combustion processes such as herbicide manufacturing, waste incineration, forest fires, and backyard trash burning. The most toxic chemical in the class is 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD). Approximately 18 million gallons of Agent Orange were sprayed by US Airforce on southern of Vietnam from 1962 to 1971. About 0.3% of Agent Orange consisted of TCDD. Dioxins have been considered highly toxic and able to cause cancer, reproductive and developmental problems, damage the immune system, and interfere with hormones. In this paper we studied gene variation in some families of dioxin victims of Vietnamese army veterans who have been exposed directly under sprays or carried out missions for at least 2 years in the heavily sprayed regions. Of the first family, we found 21 nucleotide variants in TP53 gene, 13 nucleotide variants in AhR gene. All of theme leading to amino acid change. We also found R554K in ThB4.VT16 and ThB4.VT17. This mutation changes activity for CYP1A1 induction in lymphocytes. In the second family, we identified 29 nucleotide variants in TP53 gene. Although we could not found any variant associated with phenotype of the family members but previous studies have found P295L associated with gastric carcinoma, L299P associated with pancreatic cancer, G279E associated with colorectal carcinoma and cancer of male sex cells. In the third family, we found 22 nucleotide variants in TP53 gene and 9 variants in CYP1B1 gene. For understanding of whole genome sequence variation, whole genome of 3 member of each family has been sequenced by Illumina HiSeq 2000/2500 platform. The whole genome sequence data have started analysing.

Keywords: AhR; CYP1A1; dioxin; TP53; whole genome sequence