Analysis of the Association between Catechol-O-Methyltransferase Val158Met and Male Sexual Orientation

Abstract

Introduction Male sexual orientation is thought to have a genetic component. However, previous studies have failed to generate positive results from among candidate genes. Catechol-O-methyltransferase (COMT), located on chromosome 22, has six exons, spans 27 kb, and encodes a protein of 271 amino acids. COMT has an important role in regulating the embryonic levels of catecholamine neurotransmitters (such as dopamine, norepinephrine, and epinephrine) and estrogens. COMT is also thought to be related to sexual orientation. Aims This study aimed to investigate the relationship between the COMT Val158Met variant and male sexual orientation. We performed association analysis of the COMT gene single nucleotide polymorphism, Val158Met, in 409 homosexual cases and 387 heterosexual control Chinese men. COMT polymorphism status was determined using a polymerase chain reaction-based assay. Methods Polymerase chain reaction was performed to genotype the COMT Val158Met polymorphism. Main Outcome Measures The frequency differences of the genotype and alleles distribution between the male homosexual and control groups. Results Significant differences, both in genotype and alleles, between male homosexual individuals and controls indicated a genetic component related to male homosexuality. The Val allele recessive model could be an interrelated genetic model of the cause of male homosexuality. Conclusion The COMT Val158Met variant might be associated with male sexual orientation and a recessive model was suggested.

Childhood Abuse Experiences and the COMT and MTHFR Genetic Variants Associated With Male Sexual Orientation in the Han Chinese Populations: A Case-Control Study

“…29 The COMT gene is located on chromosome 22q11, has 6 exons, spans 27 kb, and encodes a protein of 271 amino acids. 32 Genetic variations of the COMT gene directly affect the activity of the COMT enzyme. Furthermore, variations of the COMT gene influence the level of estrogen, resulting in changes to biologic traits related to dopamine and estrogen.…”

“…The main characteristics of the participants and research procedure have been described previously. 1,32 Recruitment was conducted by the Shenzhen Center for Chronic Disease Control from March 2013 to August 2015. Shenzhen Center for Chronic Disease Control is responsible for the city's prevention, treatment, and management of chronic diseases and sexually transmitted diseases.…”

“…Methods for DNA extraction and genotyping have been described previously. 32 Briefly, genomic DNA was extracted from peripheral venous blood sample using the QIAamp DNA Mini Kit (Qiagen, Valencia, CA, USA) according to the manufacturer's standard protocol and dissolved in sterile TBE buffer. The polymorphism of COMT at rs4680, rs4818, and rs6267 and that of MTHFR at rs1801133 was genotyped using the matrix-assisted laser desorption and ionization time-of-flight mass spectrometry Mass Array system (Agena iPLEXassay, San Diego, CA, USA).…”

The aminoestrogen prolame increases recognition memory and hippocampal neuronal spine density in aged mice

“…Reports indicate that the increase in locomotor activity induced by a novel environment is indicative of the hyperactivity of the dopaminergic system in the NAcc, as proposed by Deanen et al (2003) and Alquicer et al (2004), in adult rodents. In addition, it has been reported that estrogens do not alter dopamine levels in the brain (Spencer‐Segal et al, ; Yu et al, ). Therefore, we suggest that the treatment with Prolame in aged animals probably did not improve the dopaminergic neurotransmission in the NAcc because there were no significant changes in the locomotor activity induced by a novel environment between the animals administered with this amino estrogen and the vehicle.…”

The Role of Genetic Factors in the Formation of Homosexuality: Modern Analysis of the Problem

“…Исследование, проведенное в китае, указывает на связь между геном, называемым соМт, и сексуальной ориентацией [33], но расчеты свидетельствуют, что величина эффекта является слабой [32].…”