Twinning in Twin Pedigrees
نویسندگان
چکیده
منابع مشابه
Genetic modelling of dizygotic twinning in pedigrees of spontaneous dizygotic twins.
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 twin...
متن کاملNo paternal effect on monozygotic twinning in the Swedish Twin Registry.
Previous research has provided evidence for a genetic effect in monozygotic twinning, indicated by an increased risk for monozygotic women to have monozygotic offspring. However, since the biological mechanism for this trait is unknown, it is not clear if there exists a paternal inheritance. In this study we investigated twin pregnancies in offspring born in 1941-1996 to male twins in the Swedi...
متن کاملEffects of twinning on postpartum reproductive performance in cattle selected for twin births.
The effects of twinning, dystocia, retained placenta, and body weight on postpartum reproduction were evaluated for 3,370 single and 1,014 twin births. Females were bred by AI for 40 d followed by 20 or 30 d of natural service with equal numbers bred and calved in spring and fall. Percentage of dams cyclic by the end of the AI period was lower (P<.05) for dams birthing and nursing a single calf...
متن کاملTwinning in cattle.
INTRODUCTION The biological efficiency of traditional systems of beef production is low due to the low reproductive rate and the high proportion of total energy which is required for maintenance of the breeding herd. Dickerson (1978) estimated that 56% of the total feed energy intake for adult and market cattle is required solely for body maintenance (the non-productive energy requirement rises...
متن کاملTwinning rates in Tamilnadu.
A prospective study of human reproduction was conducted in Tamilnadu State, South India, from 1969 to 1975. This paper reports twinning rates and relates these to maternal age, parity, and consanguinity. Birth weights and other dimensions at birth and infant mortality are also studied. The overall twinning rate was 1 in 115 births. Dizygotic twinning rates increased significantly with maternal ...
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ژورنال
عنوان ژورنال: Journal of Epidemiology & Community Health
سال: 1950
ISSN: 0143-005X
DOI: 10.1136/jech.4.4.197