IF IDENTICAL TWINS MARRY IDENTICAL TWINS HOW GENETICALLY SIMILAR WOULD THEIR CHILDREN BE?

Identical twins Brittany and Briana Deane first met identical twins Josh and Jeremy Salyers last August at The Twins Day Festival in Ohio. A year later, the couples had their weddings, together, wearing the same wedding outfits, at this year's Twin Day Festival. Their weddings were documented for a TLC special called "Twins Marry Twins," scheduled to air in 2019.

When identical twins reproduce with identical twins the resulting children are genetically indistinguishable from full siblings. Source: http://familypedia.wikia.com/wiki/Double_first_cousin