Milk kinship hypothesis in light of epigenetic knowledge

We hypothesize that infants breastfeeding from the same woman may develop consanguinity even in cases in which they are not blood relatives, and that children of two individuals breastfed by the same woman may thus be at risk of several genetic diseases because of such consanguinity.Possible evidence for the milk kinship hypothesis is to be found in the composition of breast milk, which is composed of living substances such as stem cells or substances that can affect epigenetic regulation such as microRNAs.If these epigenetic modifications are heritable, marriages between individuals breastfed by the same woman may result in the same consequences as consanguineous marriages. In this paper, we attempt to assess this possibility.A wet nurse can be used if a baby’s natural mother is unable or chooses not to breastfeed her infant. The practice of using wet nurses is ancient and common to many cultures. After the Industrial Revolution, when wet nurses became difficult to find, human milk banking began. In Islamic law, breastfeeding institutes a form of kinship relation (milk kinship). This has historically been a medium for complex social and political networks in the Middle East. As explained in the Qur’an (An-Nisa Surah), a child who has nursed from a woman becomes a relative of the nursing woman, and also a milk sibling to others who have shared her breast, a relationship that prevents future marriage. However, the Qur’an does not explain why such marriages are forbidden.We have hypothesized that breastfeeding from the same woman may lead to consanguinity between individuals even with no blood relation, and that children born of a marriage between two such individuals may thus be at risk of certain genetic diseases as a result of this consanguinity. In this paper, we attempt to identify the possible reasons for this proposal according to current scientific knowledge.Breastfeeding provides multiple lifelong biological advantages to children, including increased surviva