Researchers have uncovered initial evidence linking genetic risk factors to borderline personality disorder (BPD).
The study, published in Nature Genetics on July 20, represents the largest genome-wide association study (GWAS) on BPD to date. It pinpointed 11 locations in the human genome associated with the disorder, revealing nine functional genes near these loci that appear to be related to BPD.
BPD affects around 2% of individuals in Western nations, with diagnoses nearly three times more common in women than in men.
The interplay of genetic and environmental influences is believed to play a role in the development of BPD. However, the field of psychiatric genetics has largely overlooked this perspective, according to study co-author Fabian Streit, a psychologist from the Central Institute of Mental Health in Mannheim, Germany. Prior to this, only one GWAS focused on BPD had been published, and it hadn’t identified any noteworthy variants associated with the condition.
The new findings indicate that “genetic approaches could yield valuable insights into this disorder, similar to research done in schizophrenia, depression, and bipolar disorder,” remarks Andrew McIntosh, a psychiatrist at the University of Edinburgh, UK.
He describes this research as a significant advancement, especially considering the lack of widespread investigation into BPD in the past.
Genetic Factors
BPD is characterized by persistent emotional instability, distortions in thought and perception, and tumultuous relationships. Often, those with the disorder experience acute crises that may lead to hospitalization, McIntosh explains.
This complexity has made it difficult to recruit participants with BPD for studies, he adds.
In this study, Streit and his team combined data from 27 separate studies focused on individuals with BPD or derived from genetic and health records in biobanks, all involving participants of European descent.
The researchers first investigated over six million genetic markers across two groups: 12,339 individuals with BPD and over one million without the condition. They identified six genome sites with genetic variants linked to BPD. These variants were validated in a follow-up analysis that included 685 people with BPD and 107,750 without.
Following this, they discovered five additional loci that may be associated with BPD. However, McIntosh notes that these “five variants still require confirmation through independent studies.”
The researchers estimated that these newly identified genetic variants account for roughly 17% of the inherited risk for BPD. This points to genetics playing a key role, although, as Streit adds, “it can never explain or portray the entire picture.”
Earlier family and twin studies have indicated that the heritability of BPD ranges from 46% to 69%.
