Most people are familiar with identical twins and fraternal twins but there is another kind – Semi Identical twins.

They are so far in fact that there are only two sets known in the world and one set is in Brisbane, a little boy and little girl.

QUT Clinical Geneticist Dr Michael Gabbett explains to Mark that what makes them so special is that they have 100 per cent of their mother’s genes and only a small amount of their dads.

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