Mallory Carlson's baby daughter Josie was diagnosed with a rare form of leukemia. Hours later, doctors discovered that her ...

It makes sense that identical twins would have the exact same DNA, right? Spoiler alert: Not always! Here's why. Identical twins (also called monozygotic or MZ twins) are conceived when a single sperm ...

Scientists describe twins as two beings who share the same uterus at the same time. They are further distinguished based on whether they developed from one or many eggs, and whether they shared a ...

These twins are not only seeing double – they’re feeling double, too. A teenage girl from Scotland has been suffering from symptoms of her identical twin’s cancer – but doctors say there’s nothing ...

They were in it to twin it — but both tied for firstborn. Twins Molly and Micky McLaren, from North Lanarkshire, Scotland, are rare “simultaneous twins” born at exactly the same time. At 11:53 on ...

For 35 years, I was certain my twin sister and I were fraternal. My sister signed us up for a twin study, where we collected our DNA with a swab. We found out we were actually identical twins. When ...

For the best experience, please enable JavaScript in your browser settings. Scientists describe twins as two beings who share the same uterus at the same time. They ...