A Common Polymorphism of the SRD5A2 Gene is Not Associated With Male-to-Female and Female-to-Male Transsexualism

Medical University of Vienna

Status

Completed

Conditions

Transsexualism

Study type

Observational

Funder types

Other

Identifiers

NCT00435513

000001

Details and patient eligibility

About

Genetic variations, i.e. polymorphisms, may be associated with gender dysphoria, e.g. transsexualism. This study aims to identify such variations.

Full description

Context: Early developmental exposure of the brain to sex steroids may play a role in the etiology of transsexualism.

Objective: To assess the association between transsexualism and allele and genotype frequencies of the steroid 5-alpha reductase (SRD5A2) Val89Leu polymorphism.

Design and Patients: We performed a case-control study of 100 male-to-female (MtF) transsexuals, 47 female-to-male (FtM) transsexuals, 755 male controls, and 915 female controls. DNA was extracted from buccal swabs and genotypes were determined by polymerase chain reaction.

Results: SRD5A2 Val89Leu allele frequencies (SRD5A2 V: 137/200 [69%] and SRD5A2 L: 63/200 [31%] vs. SRD5A2 V: 1065/1510 [71%] and SRD5A2 L: 445/1510 [29%], respectively; p=0.6; Odds Ratio [OR] 1.10; 95% Confidence Interval [CI] 0.76-1.58) and genotype distributions (SRD5A2 V/V+V/L: 92/100 [92%] and L/L 8/100 [8%] vs. SRD5A2 V/V+V/L: 683/755 [91%] and L/L 72/755 [9%], respectively, p=0.7; OR 0.82; 95% CI 0.24-2.84) were not significantly different between MtF transsexuals and male controls. SRD5A2 Val89Leu allele frequencies (SRD5A2 V: 70/94 [74%] and SRD5A2 L: 24/94 [26%] vs. SRD5A2 V: 1253/1830 [69%] and SRD5A2 L: 573/1830 [31%], respectively; p=0.3; OR 0.75; 95% CI 0.45-1.26) and genotype distributions (SRD5A2 V/V+V/L: 44/47 [93%] and L/L 3/47 [7%] vs. SRD5A2 V/V+V/L: 823/915 [90%] and L/L 92/915 [10%], respectively, p=0.6; OR 0.61; 95% CI 0.11-3.32) were also not significantly different between FtM transsexuals and female controls. Of note, there was no gender-specific genotype distribution among controls.

Conclusions: The SRD5A2 Val89Leu polymorphism is not associated with transsexualism and is no candidate gene of this condition.

Enrollment

1,770 patients

Sex

All

Ages

18 to 80 years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria