Determination of Zygosity in Adult Chinese Twins Using the 450K Methylation Array versus Questionnaire Data.
Previous studies have shown that both single nucleotide polymorphisms (SNPs) and questionnaires-based method can be used for twin zygosity determination, but few validation studies have been conducted using Chinese populations. In the current study, we recruited 192 same sex Chinese adult twin pairs to evaluate the validity of using genetic markers-based method and questionnaire-based method in zygosity determination. We considered the relatedness analysis based on more than 0.6 million SNPs genotyping as the golden standards for zygosity determination. After quality control, qualified twins were left for relatedness analysis based on identical by descent calculation. Then those same sex twin pairs were included in the zygosity questionnaire validation analysis. Logistic regression model was applied to assess the discriminant ability of age, sex and the three questions in zygosity determination. Leave one out cross-validation was used as a measurement of internal validation. The results of zygosity determination based on 65 SNPs in 450k methylation array were all consistent with genotyping. Age, gender, questions of appearance confused by strangers and previously perceived zygosity consisted of the most predictable model with a consistency rate of 0.8698, cross validation predictive error of 0.1347. For twin studies with genotyping and\or 450k methylation array, there would be no need to conduct other zygosity testing for the sake of costs consideration.
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China.
Biqi
B
Wang
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China.
Wenjing
W
Gao
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China.
Canqing
C
Yu
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China.
Weihua
W
Cao
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China.
Jun
J
Lv
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China.
Shengfeng
S
Wang
Qingdao Center for Diseases Control and Prevention, Qingdao, 266033, China.
Zengchang
Z
Pang
Zhejiang Center for Disease Control and Prevention, Hangzhou, 310051, China.
Liming
L
Cong
Jiangsu Center for Disease Control and Prevention, Nanjing, 210009, China.
Hua
H
Wang
Sichuan Center for Disease Control and Prevention, Chengdu, 610041, China.
Xianping
X
Wu
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China.
Liming
L
Li
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019175:DNA Methylation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D011795:Surveys and Questionnaires; D014429:Twins, Dizygotic / Q000235:genetics*; D014430:Twins, Monozygotic / Q000235:genetics*