title: Excessive twinning in a rural American genealogy.
abstract: A family record of 1693 descendants in rural Missouri exhibits a twinning rate of 2 X 2%. Weinberg's Differential Rule estimates the level of monozygosity in this twin sample at 61-83%, unlike previous results dominated by dizygosity . These historical data cannot directly support a genetic basis for monozygosity though. Clinical studies seem the best solution to the genetics of twinning.
mesh_terms: D005260:Female; D005789:Genealogy and Heraldry; D006801:Humans; D008297:Male; D011247:Pregnancy; D012424:Rural Population; D013223:Statistics as Topic; D014427:Twins; D014430:Twins, Monozygotic; D014481:United States