I am not a lawyer, and the laws regarding inheritance can vary significantly depending on your jurisdiction. It is crucial to consult with a qualified legal professional to get accurate advice tailored to your specific situation.
In general, if the DNA test indicates that your 50-year-old son is not biologically related to you, it might have implications on his legal status as your heir. In many legal systems, inheritance is based on blood relations, and if there is no biological connection, your son may not have a legal claim to your estate as a biological child would.
However, some jurisdictions recognize "adoptive" or "equitable" inheritance rights for individuals who were raised as a member of the family, even if they are not biologically related. This would depend on the specific laws in your area and whether there is any legal recognition of a parent-child relationship based on emotional or adoptive ties.
The situation can be complex, and other factors, such as existing wills or estate planning documents, can also impact inheritance rights. Therefore, it is essential to seek professional legal advice to understand how this situation may affect your estate and to ensure that your wishes for inheritance are carried out appropriately.