Impact of genetic variation in interleukin-1 receptor antagonist and melanocortin-1 receptor genes on vulvar vestibulitis syndrome.
OBJECTIVE
To investigate the risk of vulvar vestibulitis syndrome (VVS) in the presence of specific genetic variants (polymorphisms) that affect chronic inflammation, pain and skin color.


METHODS
For a retrospective, case-control study performed at a university-based ambulatory gynecologic service, 36 consecutive VVS cases and 69 consecutive pain-free controls were selected. Polymerase chain reaction products containing genetic variants of 2 genes, the interleukin-1 receptor antagonist (IL1RN) and melanocortin-1 receptor (MC1R), were analyzed by 2 independent techniques, gel electrophoresis and direct sequencing.


RESULTS
VVS cases were significantly more likely to be homozygous (+/+) for allele 2 of IL1RN as compared to controls (OR=4.4, 95% CI 1.11-17.14, P=.032). VVS cases were more likely to carry at least 1 of 6 loss-of-function polymorphisms of the MC1R gene as compared to controls, overall (OR=3.5, 95% CI 1.45-8.37, P=.005) and adjusted for race (OR=2.6, 95% CI 1.06-6.51, P=.037). The combined presence of allele 2 (+/+) IL1RN and at least 1 of the 6 MC1R polymorphisms resulted in an additive risk for VVS (OR=8.5; additive risk for VVS (OR=8.5; P=.046).


CONCLUSIONS
The risk of VVS is increased with proinflammatory genetic variants of IL1RN and MC1R, and combined genetic effects are associated with additive risk. This study supports a genetic contribution to VVS, suggests an increased risk of VVS in women withfair skin and indicates potential new treatment and primary prevention options.
Foster
David C
DC
Division of Gynecologic Specialties, Department of Obstetrics and Gynecology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA. david_foster@urmc.rochester.edu
Sazenski
Todd M
TM
Stodgell
Christopher J
CJ
D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D010146:Pain / Q000209:etiology; D011110:Polymorphism, Genetic; D044102:Receptor, Melanocortin, Type 1 / Q000235:genetics*; D012189:Retrospective Studies; D012795:Sialoglycoproteins / Q000235:genetics*; D014845:Vulvar Diseases / Q000150:complications / Q000235:genetics*
C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D044102:Receptor, Melanocortin, Type 1; D012795:Sialoglycoproteins