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 ...

Looking into how twins’ genetics work can give researchers new insights into how different lifestyles and habits affect two people with the same genetic blueprint. Identical twins Marzieh and Razieh ...

Around 1 in 250 pregnancies result in identical or “monozygotic” twins, but the mechanism behind monozygotic twinning has remained elusive, partly because the phenomenon is so rare and partly due to ...

Although there are some rare exceptions, identical twins are almost always the same sex. Because identical twins occur when a single fertilized egg splits and forms two embryos, each embryo has the ...

When you’ve just had identical twins, it’s normal to spend a lot of time looking down at their squishy little bodies and analyzing every subtle way they differ from one another. Unlike fraternal twins ...

You've probably heard of identical and fraternal twins, but a report published Thursday says there's a third kind -- sesquizygous twins or "semi-identical." Identical -- or monozygotic -- twins pop up ...

For the best experience, please enable JavaScript in your browser settings. Following the Kakamega twin puzzle that has drawn the attention of the entire country, we ...