The final sample comprised 3,824 participants from a target sample of 5,004 individuals who provided with consent for QIMR to approach them and included: 3,348 twin individuals, including: (a) 976 monozygotic female (MZF), with 398 pairs and 180 unpaired twins; (b) 490 monozy-gotic male (MZM), with 173 pairs and 144 unpaired twins; (c) 741 dizygotic female (DZF), with 305 pairs and 131 unpaired twins; (d) 373 dizygotic male (DZM), with 118 pairs and 137 unpaired twins; and (e) 746 dizygotic opposite sex (DZOS), with 231 pairs and 284 unpaired twins. There were 22 twins with undetermined zygosity and 476 nontwin siblings.
