Ooki S, Yamada K, Asaka A, Hayakawa K
School of Health Sciences, Faculty of Medicine, University of Tokyo, Japan.
Acta Genet Med Gemellol (Roma). 1990;39(1):109-15. doi: 10.1017/s0001566000005626.
Subjects were 189 twin pairs, 165 MZ and 24 same-sexed DZ, who entered the junior high school affiliated to Tokyo University (sample T), and 93 twin pairs, 71 MZ and 22 same-sexed DZ, who were registered at Kinki University (sample K). The zygosity was previously identified by many genetic markers, and this study aimed at zygosity diagnosis by questionnaire. The latter included three questions: "How are you alike?", "How often are you mistaken?", and "By whom are you mistaken?". According to the degree, 1-3 points, 1-3 points, and 1-4 points were given for each question, and the sum of the points of each pair of twins was calculated. Zygosity was determined by the sum of points, distributed from 6 to 20. Namely, if the sum was 6-13, the twin pair was considered MZ, and if the sum was 14-20, DZ. More than 90% of twins were diagnosed correctly by use of this cutting point. This result was in accordance with that obtained by use of discriminated function analysis. It is concluded that zygosity diagnosis by questionnaire is convenient and useful, in particular for epidemiological research.
研究对象为189对双胞胎，其中165对同卵双胞胎和24对同性异卵双胞胎，他们就读于东京大学附属初中（样本T）；还有93对双胞胎，其中71对同卵双胞胎和22对同性异卵双胞胎，他们在近畿大学注册登记（样本K）。此前通过多种基因标记确定了双胞胎的合子性，本研究旨在通过问卷调查进行合子性诊断。问卷包括三个问题：“你们有多相像？”“你们多久被认错一次？”以及“你们被谁认错？”。根据程度，每个问题分别给予1 - 3分、1 - 3分和1 - 4分，并计算每对双胞胎的得分总和。合子性由得分总和决定，范围为6至20分。也就是说，如果总和为6 - 13分，则该对双胞胎被认为是同卵双胞胎；如果总和为14 - 20分，则为异卵双胞胎。使用这个分界点，超过90%的双胞胎被正确诊断。这一结果与通过判别函数分析得到的结果一致。得出结论，通过问卷调查进行合子性诊断方便且有用，尤其适用于流行病学研究。
