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

Association Study of a SRD5A2 SNP and Transsexualism.

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT00435513

Enrollment

1770

Registered

2007-02-15

Start date

2007-03-31

Completion date

2008-07-31

Last updated

2015-05-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Transsexualism

Brief summary

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

Detailed 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.

Interventions

None listed

Study design

Observational model

CASE_CONTROL

Time perspective

RETROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to 80 Years

Healthy volunteers

Yes

Inclusion criteria

* transsexual individuals as defined by DSM IV criteria

Exclusion criteria

* unwillingness to participate

Countries

Austria

Outcome results