Male Pair-Bonding Gene AVPR1A STR Test

What is the Male Pair-Bonding Gene?

The male pair-bonding gene is sometimes referred to as the male infidelity gene. It is a genetic variant of the AVPR1A gene. The AVPR1A gene encodes a protein called arginine vasopressin receptor 1A. AVPR1A variation can occur in the regulatory region of the gene at three different repetitive sequences, known as RS1, RS3 and GT25. A specific version of RS3, known as the RS3 334 allele is associated with diminished pair-boding in males.

Men with the RS3 334 allele are less likely to form a strong bond with their partners and are more likely to experience marital crisis or divorce. They are less likely to get married and more likely to cohabitate, than individuals without the RS3 334 allele. Spouses of men with the RS3 334 allele report feeling less affection and consensus in the marriage. These associations are not seen in women with the RS3 334 allele. However, an increased likelihood of infidelity in females is associated with five different changes in the AVPR1A gene.

What is the Function of the Arginine Vasopressin Receptor 1A?

Vasopressin is a hormone or “chemical messenger” that promotes water retention in the kidneys and increases blood pressure. Most of these effects take place when vasopressin is released into the blood stream. Vasopressin can also be released directly into the brain and influence social and sexual behavior (such as infidelity). The arginine vasopressin receptor 1A binds vasopressin and transmits the signal into the cells.

Conditions Associated with the AVPR1A Gene 

Genetic changes in AVPR1A are linked to an increased likelihood of infidelity in both men and women. Other changes in the AVPR1A gene are also associated with:

• Autism
• Altruistic behaviour
• Addictive behaviour
• Eating disorders
• Social behaviour such as sibling interactions

DNA Testing for the Pair-Bonding Gene in Males

The AVPR1A gene is located on chromosome 12. We inherit two copies of the gene - one from each parent. A simple DNA test can be done to find out which forms of AVPR1A a person has inherited. The different versions of AVPR1A are due to short tandem repeats (STRs) in the regulatory region that controls the protein levels. The AVPR1A STR test determines the length of the repeat region and determines if the person has the RS3 334 infidelity variant. Approximately 40% of Caucasian men have at least one copy of the AVPR1A RS3 334 allele. The prevalence in other populations has not been studied.

Females are unaffected by variation in the the number of RS3 repeats. Males who have one copy of the RS3 334 allele (heterozygotes), have a decreased likelihood of forming a strong bond with their partner. Males who have inherited two copies of the RS3 334 allele (homozygotes) are more likely to experience marital crisis or threat of divorce (34%) than men with other versions of the AVPR1A gene (15%). RS3 334 homozygotes are also more likely to cohabitate, rather than take the next step into marriage.

Recommended Links:

Walum H et al. (2008). Genetic variation in the vasopressin receptor 1a gene (AVPR1A) associates with pair-bonding behavior in humans. Proceedings of the National Academy of Sciences of the United States of America. 105(37): 14153-14156.