Key points: 1  DNA cloning is a molecular biology technique that makes many identical copies of a piece of DNA, such as a gene. 2  In a typical cloning experiment, a target gene is inserted into a circular piece of DNA called a plasmid.
1 Some studies of twins and families suggest that personality disorders may be inherited or strongly associated with other mental disorders among family members. 2  Brain abnormalities. 3  Some research has shown changes in certain areas of the brain involved in emotion regulation, impulsivity and aggression.auses. As with other mental disorders, the causes of borderline personality disorder aren't fully understood. In addition to environmental factors â such as a history of child abuse or neglect â borderline personality disorder may be linked to:
1 Borderline personality disorder. 2  There is a tendency for loved ones of people with borderline personality disorder (BPD) to slip into caretaker roles, giving priority and focus to problems in the life of the person with BPD rather than to issues in their own lives.