Hostname: page-component-76fb5796d-5g6vh Total loading time: 0 Render date: 2024-04-25T08:17:34.858Z Has data issue: false hasContentIssue false

Zygosity Diagnosis of Twins by Questionnaire for Twins’ Mothers

Published online by Cambridge University Press:  06 September 2016

S. Ooki*
Affiliation:
Department of Health Sciences, Yamanashi Medical University
K. Yamada
Affiliation:
Department of Nursing, Sapporo Medical College, Japan
A. Asaka
Affiliation:
Department of Health Sciences, Yamanashi Medical University
*
Department of Health Sciences, Yamanashi Medical University, Tamaho, Yamanashi, 409-38Japan

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Subjects were 74 twin pairs, 61 MZs and 13 same-sexed DZs who entered the High School affiliated with Tokyo University, Japan. Their mothers also participated. The twins’ zygosity was previously identified by many genetic markers. This study aimed at clarifying the effectiveness of zygosity diagnosis by questionnaires distributed to twins’ mothers. The questionnaire consisted of three questions concerning the degree of similarity of twins at one year of age; whether they were confused, and if so, by whom. It was slightly modified from that reported earlier by Ooki et al [11] for twins themselves. According to the degree of similarity of the twins, points were allotted thus: from 1 to 3 points for answers to questions (1) and (2) and from 1 to 4 points for answers to questions (3). The sum of the points was calculated, then ranged from 3 to 10. Zygosity was determined by the sum of these points. If the sum was 3-6, the twin pairs were considered MZ and if the sum was 7-10 DZ. It was revealed that more than 90% of twins were identified correctly as MZ or DZ by applying this cutting point and this result was in accordance with that obtained by use of discriminant function analysis. Moreover, the accuracy of the mothers’ responses was nearly the same as that obtained by the questionnaire for twins themselves. It was concluded, therefore, that the information from twins’ mothers is as correct as that from twins themselves. This questionnaire is simple, practical and especially useful when twins are still too young to participate personally.

Type
Research Article
Copyright
Copyright © The International Society for Twin Studies 1993

References

REFERENCES

1. Bonnelykke, B, Hauge, M, Holm, N et al (1989): Evaluation of zygosity diagnosis in twin pairs below age seven by means of a mailed questionnaire. Acta Genet Med Gemellol 38:305313.Google Scholar
2. Cederlof, R, Friberg, L, Jonsson, E et al (1961): Studies on similarity diagnosis in twins with the aid of mailed questionnaires. Acta Genet Med Gemellol 11:338362.Google Scholar
3. Cohen, DJ, Dibble, E, Grawe, JM et al (1973): Separating identical from fraternal twins. Arch Gen Psychiatry 29:465469.Google Scholar
4. Cohen, DJ, Dibble, E, Grawe, JM et al (1975): Reliably separating identical from fraternal twins. Arch Gen Psychiatry 32:13711375.Google Scholar
5. Eisen, S, Neuman, R, Goldberg, J et al (1989): Determining zygosity in the Vietnam Era Twin Registry: An approach using questionnaires. Clin Genet 35:423432.Google Scholar
6. Gedda, L, Milani-Comparetti, M, D’Alessandro, E (1976): “Equivocalness” and other empirical methods in zygosity assessment. Acta Genet Med Gemellol 25:117120.CrossRefGoogle ScholarPubMed
7. Jablon, S, Neer, J, Gershowitz, H et al (1967): The NAS-NRC Twin Panel: Method of construction of the panel, zygosity diagnosis, and proposed use. Am J Hum Genet 19:133161.Google Scholar
8. Kasriel, J, Eaves, L (19767): The zygosity of twins further evidence on the agreement between diagnosis by blood groups and written questionnaires. J Biosoc Sci 8:263266.Google Scholar
9. Magnus, P, Berg, K, Nance, WE (1983): Predicting zygosity in Norwegian twin pairs born 1915–1960. Clin Genet 24:103112.CrossRefGoogle ScholarPubMed
10. Nichols, RC, Bilbro, WC (1966): The diagnosis of twin zygosity. Acta Genet Basel 16:265275.Google Scholar
11. Ooki, S. Yamada, K, Asaka, A et al (1990): Zygosity diagnosis of twins by questionnaire. Acta Genet Med Gemellol 39:109115.Google Scholar
12. Sarna, S, Kaprio, J, Sistonen, P et al (1978): Diagnosis of twin zygosity by mailed questionnaire. Hum Hered 28:241254.Google Scholar
13. Schoenfeldt, LF (1969): A comparison of two analytic procedures for estimating twin zygosity. Hum Hered 19:343353.CrossRefGoogle ScholarPubMed
14. Torgersen, S (1979): The determination of twin zygosity by means of a mailed questionnaire. Acta Genet Med Gemellol 28:225236.Google Scholar