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:
Causes of borderline personality disorder. Most experts agree that there is no single cause of borderline personality disorder (BPD). It is likely to be caused by a combination of factors.These include: 1  genetics â g enes you inherit from your parents may make you more vulnerable to developing BPD, given certain environmental factors (see below).eurotransmitters. It is thought that many people with BPD may have altered functioning of a neurotransmitter called serotonin in their brain. Altered serotonin activity in the brain has been linked to depression, aggression and difficulty in controlling destructive urges.