Hi Peka, In the released genotyping-verified DZ twins, there actually is one M/F twin pair, but only one, which is unexpected if our recruiting of twins were matched to the population. Although we did not specifically exclude DZ twins discordant in sex for HCP, we did recruit most of our twin subjects from previous twin studies that specified same sex twins (MZ or DZ) because of potential sex confounds in making comparisons between twins/twin types and to avoid sex being a confound for dizygosity.
Best, Jennifer Jennifer Elam, Ph.D. Scientific Outreach, Human Connectome Project Washington University School of Medicine Department of Neuroscience, Box 8108 660 South Euclid Avenue St. Louis, MO 63110 314-362-9387<tel:314-362-9387> e...@wustl.edu<mailto:e...@wustl.edu> www.humanconnectome.org<http://www.humanconnectome.org/> ________________________________ From: hcp-users-boun...@humanconnectome.org <hcp-users-boun...@humanconnectome.org> on behalf of Peka Savayan <savay...@umn.edu> Sent: Friday, August 11, 2017 10:49:13 AM To: hcp-users@humanconnectome.org Subject: [HCP-Users] opposite sex dizygotic twins Hi experts, In the final data release of 1206 subjects, out of 1113 subjects with MRI data 1053 have genetically confirmed family relations. Of those, there are 158 (79 pairs) dizygotic (DZ) twins. For all DZ pairs, twins in the pair have the SAME sex. However, Hulshoff Pol, Schnack et al. (J. Neuroscience 2006, 26(40):10235-10242) reported that 21 out of 58 DZ pairs (36%) were of OPPOSITE sex within the pair. 1. Is my observation correct? 2. Can you explain the 100% SAME sex DZ within-pair twins? Can you comment, please? Thank you. Peka -- Peka Christova Savayan, PhD Assistant Prof. Dept. Neuroscience Univ. Minnesota Graduate program Center Cognitive Sciences Univ. Minnesota Research Physicist Brain Sciences Center VAHCS _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users