ArticleBiology of sex differences2018
Risk of epilepsy in opposite-sex and same-sex twins: a twin cohort study.
Article in Biology of sex differences, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
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2 citing papers in PubMed, 3 citations in OpenAlex.
- Prevalence of Epilepsy across 25 Sub-Counties in Three Districts of Northern Uganda.Neuroepidemiology · 2026Article
- Opposite-sex and same-sex twin studies of physiological, cognitive and behavioral traits.Neuroscience and biobehavioral reviews · 2020Review
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7 authors at 4 institutions in 3 countries.
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No grant is acknowledged in the PubMed record.
Abstract
backgroundThere is a complex interaction between female and male sex hormones and the risk of epilepsy. Whether prenatal exposure to higher levels of sex hormones affects the development of epilepsy in childhood or later in life is not well known. The sex hormone environment of fetuses may be affected by the sex of the co-twin. We estimated the risk of epilepsy for twins with an opposite-sex (OS) co-twin compared with twins with a same-sex (SS) co-twin.
methodsFrom the Danish Twin Registry, we identified OS female twins (n = 11,078), SS female twins (n = 19,186), OS male twins (n = 11,080), and SS male twins (n = 20,207) born between 1977 and 2009. The SS twins include monozygotic twins, dizygotic twins, and twins with unknown zygosity. These children were followed up from day 29 after birth until diagnosis of epilepsy, death, emigration, or end of follow-up (31 December 2011) whichever came first. Information on diagnosis of epilepsy was obtained from the Danish National Patient Registry. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for epilepsy in the OS twins using a Cox proportional hazards regression model compared with the SS twins. To account for the correlation of twins from the same mother when estimating standard errors, we used the cluster option in Stata.
resultsWe identified 152 OS female twins, 282 SS female twins, 162 OS male twins, and 335 SS male twins diagnosed with epilepsy corresponding to an incidence rate of 9.9 and 9.7 per 10,000 person years for the OS and SS female twins, and 10.6 and 10.9 per 10,000 person years for the OS and SS male twins, respectively. We found a similar risk of epilepsy among the OS and SS female twins [HR = 1.01; 95% CI 0.83-1.24] as well as among the OS and SS male twins [HR = 0.94; 95% CI 0.78-1.14]
conclusionsIn this population-based study of Danish twins, we did not find difference in the risk of epilepsy between twins with an OS co-twin and twins with a SS co-twin. This applied to both female and male twins. The study therefore does not support the hypothesis that subtle hormone difference in fetal life due to co-twin may play a role in the development of epilepsy later in life.
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