Related by context. Frequent words. (Click for all words.) 63 identical twins 60 fraternal twins 54 Siblings 52 Conjoined twins 49 twins 46 fraternal twin 46 twin sisters 45 quintuplets 44 triplets 43 quadruplets 41 siblings 41 twin brother 40 Premature babies 39 Married couples 39 identical twin 39 Fanconi anemia 39 triplet 39 sibs 38 conjoined twins 37 Goalies 37 childhood sweethearts 37 Fifth graders 36 Goaltenders 36 Sophomores 36 Seventh graders 36 Siamese twins 35 Geneticists 35 genetic susceptibility 35 twin sister 35 conjoined 35 Newlyweds 35 Freshmen 35 polar opposites 34 mitochondrial disease 34 cousins 34 Eighth graders 34 genetic abnormalities 34 genetic makeup 34 Ever wonder 34 premature birth 34 twins triplets 34 conjoined twin 34 Kindergartners 34 Teenagers 33 Sixth graders 33 Air Force Airman 33 hypoplastic left 33 brothers 33 chromosomal abnormalities 33 Grandparents 33 sibling rivalry 33 birth defect 33 Opposites 33 Nineteen 33 microcephaly 33 congenital defects 33 genetically 33 Expectant mothers 33 transplant recipient 33 newlyweds 33 chromosomes 33 born prematurely 33 twin daughters 33 malformation 33 Eighteen 32 genetic defect 32 infertility treatments 32 Separated 32 Orangutans 32 DO YOU THINK 32 stepbrothers 32 Outfielders 32 stepfamilies 32 sisters 32 gene mutation 32 sibling 32 soulmates 32 duos 32 spina bifida 32 heritability 32 genetic disorder 31 distant cousins 31 Identical 31 cohabitating 31 dwarfism 31 THEY 31 genetics 31 congenital abnormalities 31 sons 31 Sixteen 31 opposites 31 upbringings 31 conceive naturally 31 congenital heart 31 doppelgangers 31 mouse embryos 31 daughters 31 Ever wondered 31 Neurosurgeons 31 Males 31 adoptive parents