Genetic modelling of dizygotic twinning in pedigrees of spontaneous dizygotic twins

Journal Article · Mon Jan 22 00:00:00 EST 1996 · American Journal of Medical Genetics

DOI:https://doi.org/10.1002/(SICI)1096-8628(19960122)61:3<258::AID-AJMG10>3.0.CO;2-S· OSTI ID:426133

Meulemans, W J; Derom, C A; Derom, R M ^[1]

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1. Univ. of Leuven (Belgium); and others

The inheritance of spontaneous dizygotic (DZ) twinning was investigated in 1,422 three-generation pedigrees ascertained through mothers of spontaneous DZ proband twins. DZ twinning was modelled as a trait expressed only in women. The penetrance was modelled first as a parity independent and secondly as parity dependent. The observed frequencies of maternal and paternal grandmothers with DZ twins differed significantly from the expectations under an X-linked mode of inheritance. Complex segregation analysis showed that the parity-independent phenotype of {open_quotes}having DZ twins{close_quotes} was consistent with an autosomal monogenic dominant model, with a gene frequency of 0.035 and a female-specific lifetime penetrance of 0.10. Recessive, polygenic, and sporadic models were rejected. The autosomal dominant model revealed a strong robustness against a changing population prevalence and the loss of information due to the presence of same-sexed twin pairs of unknown zygosity. When DZ twinning was modelled as a parity dependent trait, the data were compatible with an autosomal dominant model with a gene frequency of 0.306 and a penetrance of 0.03 per birth for female gene carriers. 19 refs., 5 tabs.

• OSTI ID: 426133
• Journal Information: American Journal of Medical Genetics, Vol. 61, Issue 3; Other Information: PBD: 22 Jan 1996
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
GENETICS
STATISTICAL MODELS
HUMAN X CHROMOSOME
POPULATION DYNAMICS
GENES
PHENOTYPE