Identical, or monozygotic, twins develop from the same fertilized egg that splits into two. These twins are the same sex and share the same genes. Sometimes called paternal twins, identical twins ...

Every summer, on the first weekend in August, thousands of twins converge on Twinsburg, Ohio, a small town southeast of Cleveland named by identical twin brothers nearly two centuries ago.

MZ twins are generally assumed to be genetically identical, although some genetic and epigenetic differences have now been described. A newly published finding that phenotypically concordant as ...