Related by context. Frequent words. (Click for all words.) 73 fraternal twins 63 twins 59 identical twin 55 triplets 50 conjoined twins 50 quadruplets 47 siblings 47 quintuplets 46 triplet 46 twin sisters 46 genetically identical 46 conjoined 45 polar opposites 44 genetically 44 Siblings 43 genetic 42 sisters 41 twin brother 41 opposites 41 heredity 41 chromosomes 41 mutated gene 41 fathers 41 brothers 40 chromosomal 40 happily married 39 genetic defect 39 offspring 39 genetic predisposition 39 adoptive parents 39 gene mutation 39 breastfed 39 cohabiting 39 twin sister 39 genetic mutation 38 singletons 38 Down syndrome 38 born prematurely 38 familial 38 genes 38 gene variants 38 genetic mutations 38 heterosexual 38 stillbirth 38 sibling 38 genetic makeup 37 gene variant 37 divorced 37 distant cousins 37 genetic markers 37 pre eclampsia 37 genetic variants 37 temperaments 37 X chromosome 37 soulmates 37 genetic variations 37 genetic disorder 37 defective gene 37 bone marrow transplants 37 sexes 37 born 37 personality traits 37 artificially inseminated 37 utero 36 firstborn 36 childless 36 sperm donor 36 genetic variant 36 brunettes 36 IQs 36 chromosome 36 mitochondrial DNA 36 married 36 duos 36 couples 36 babies 36 inseparable 36 Caucasian 36 preterm 35 monogamous 35 genetic defects 35 abnormalities 35 genetics 35 malformations 35 trios 35 twosome 35 malformation 35 cortisol levels 35 cardiomyopathy 35 sibling rivalry 35 BRCA2 35 identical 35 Caucasians 35 womb 35 embryo 34 alleles 34 embryos 34 dissimilar 34 surrogate mothers 34 sextuplets 34 platonic