For the first time, a team of researchers has found a specific place in the human genome that raises a person's risk of erectile dysfunction. The discovery is a significant advancement in the understanding of the genetics underlying erectile dysfunction. The study, "Genetic variation in the SIM1 locus is associated with erectile dysfunction," will be published the week of October 8 in the journal Proceedings of the National Academy of Sciences.
Erectile dysfunction, the inability to obtain and maintain an erection sufficient for sexual activity, is a common and costly condition of men of primarily middle and older ages. The disease is linked to many causes, such as neurological, hormonal and vascular factors.
Therapies based on these factors exist, but many men don't respond to them. Genetics also are suspected as a factor in about one-third of erectile dysfunction cases, but researchers have failed to make an association with any specific genomic locations until now.
The new study found that variations in a specific place in the genome -- called a genetic locus -- near the SIM1 gene are significantly associated with an increased risk of erectile dysfunction. The researchers ruled out that the risk was due to other known risk factors for erectile dysfunction, such as body mass index, or differences in how men describe their erectile dysfunction. The study also demonstrated a biological role for the genetic location in regulating sexual function, strongly suggesting that these variations can cause erectile dysfunction.
"Identifying this SIM1 locus as a risk factor for erectile dysfunction is a big deal because it provides the long sought-after proof that there is a genetic component to the disease," said the study's lead author, Eric Jorgenson, PhD, a research scientist at Kaiser Permanente Northern California's Division of Research. "Identifying the first genetic risk factor for erectile dysfunction is an exciting discovery because it opens the door for investigations into new, genetic-based therapies."
The researchers conducted a genome-wide association study in two large and diverse cohorts to investigate genetic contributors to the risk of erectile dysfunction. The first cohort included 36,648 men from the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort, which is part of the Kaiser Permanente Research Program on Genes, Environment and Health, a research program affiliated with the Kaiser Permanente Research Bank. The Research Bank supports external and internal investigation into a variety of health conditions and diseases and includes biospecimens from more than 320,000 consenting Kaiser Permanente members, as well as linked genetic, environmental and health data.
The GERA cohort included male members of Kaiser Permanente who completed a survey on their condition, had a clinical diagnosis of erectile dysfunction based on their electronic health records, and had used drugs or other erectile dysfunction treatments. The findings in the GERA cohort were then verified in a cohort of 222,358 men from the U.K. Biobank.