Men can also be such carriers, albeit it is only typically passed from mother to son or by blood transfusion.
Does this serve to diversify the genetic pool and help prevent inbreeding frailties in small isolated populations? Or is it detrimental long term due to the effects of miscegenation leading to mutts that don't adequately identify with their peers? Eg. this phenomenon is less common in homogeneous patriarchal societies (eg east asia) and more common in matriarchal societies (eg. Africa.) Has this affected the viability of such populations in terms of long term development? Note that most European societies were also highly homogeneous prior to the 1960's.
What I'm getting at is definitely political. Civilizations benefit from interacting, the periphery between different cultures is the hotbed of conflict, idea transfer and ultimately new technologies. But do their benefit from mixing?