Aussie doctors discover ‘exceptionally rare’ semi-identical boy and girl twins

The sesquizygotic twins share 100% of their mother's genes but only a proportion of their father's DNA
Australian Associated Press

A set of Australian twins — a boy and a girl — have been identified as just the second in the world to be created from one egg and two sperm, and the first to be discovered during pregnancy.

Semi-identical twins are extraordinarily rare, according to New England Journal of Medicine report on the twins born in Queensland four years ago.