title: The sex ratios of monozygotic and dizygotic twins.
abstract: Fellman and Eriksson (2010) cited my suggestion that the sex ratio (proportion male) of monozygotic (MZ) twins is lower than that of dizygotic (DZ) twins (James 1975). Here I offer elaborations on and potential explanations for this.
authors: The Galton Laboratory, Department of Genetics, Evolution and Environment, University College London, UK. whjames@waitrose.com
authors: William H
authors: WH
authors: James
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D012744:Sex Ratio; D014429:Twins, Dizygotic / Q000235:genetics*; D014430:Twins, Monozygotic / Q000235:genetics*; D049951:X Chromosome Inactivation / Q000235:genetics