Table 1.

Genetic studies on paranoid, schizotypal, antisocial personality disorders and related traits

Polymorphism investigated	Target group	Analysis	Findings	Authors
Paranoid personality disorder
Serotonin transporter  5-HTTLPR	114 (35 males) affective disorder, 110 (63 males) schizophrenia spectrum disorders, 124 (46 males) controls	ANOVA	Short allele genotype of 5-HTTLPR associated with lower paranoid score on MMPI	Golimbet et al., 2003 [7]
Catechol-O-methyltransferase  Val158Met	1657 young males aged 18–24 years	ANOVA	Positive association between Val allele and paranoid factor	Smyrnis et al., 2007 [8]
CACNA1C  rs1006737	530 randomly-selected males	ANOVA	A-allele associated with higher paranoid ideation scores on STQ	Roussos et al., 2011 [9]
	50 (31 males) schizotypal personality disorder, 48 (28 males) controls	Student’s t-test	Associated with paranoid ideation scores of STQ	Roussos et al., 2013 [10]
Schizotypal personality disorder
Catechol-O-methyltransferase  Val158Met	67 schizotypal personality disorder patients 154 patients with other personality disorders, 60 controls	χ2, MANCOVA, ANCOVA	Related to prefrontal cortex-dependent performance Might contribute to the deficit in prefrontal-dependent memory processes	Minzenberg et al., 2006 [11]
	908 young males aged 18–24 years	ANOVA	Positively associated with magical thinking, constricted affect, odd speech, negative factor, disorganization symptoms, paranoid factor scores as well as total score on SPQ	Smyrnis et al., 2007 [8]
	522 (267 males) psychiatrically normal individuals	ANOVA	Met/Met and Val/Met carriers score highest in an executive function test Met/Met genotype carriers are more disorganized than those with the Val/Val genotype	Sheldrick et al., 2008 [12]
	27 (10 males) unaffected first-degree relatives of schizophrenic patients 22 (8 males) unaffected first-degree relatives of bipolar probands 57 (32 males) controls	ANOVA	Val/ Val carriers had highest mean score on full SPQ. Val allele associated with higher positive and negative dimension scores on SPQ	Schürhoff et al., 2007 [13]
	465 (231 males) healthy community dwelling adults	Regression, ANOVA	Weak association with the odd speech subscale on SPQ Weak association with disorganization factor on SPQ (when only males analyzed) Individuals with Val/Val genotype showed the lowest SPQ scores (when only males analyzed)	Ma et al., 2007 [14]
p250GAP  rs2298599	431 (210 males) schizophrenia, 572 (267 males) controls	ANOVA	A/A genotype frequency higher in patients A/A carriers showed higher scores on schizotypal traits	Ohi et al., 2012 [15]
CACNA1C  rs1006737	50 schizotypal personality disorder, 48 controls	Student’s t-test	Associated with paranoid ideation subscale of STQ	Roussos et al., 2013 [10]
Antisocial personality disorder
Serotonin transporter  5-HTTLPR  5-HTTVNTR Dopamine transporter  DATVNTR	311 male heroin-dependents with ASPD 277 male heroin-dependents without ASPD 194 male controls	Multifactor dimensionality reduction	Higher 12R/10R genotype frequency in 5-HTTVNTR of heroin-dependents with ASPD than both controls and heroin-dependents without ASPD The interaction of 5-HTTVNTR and DATVNTR is associated with ASPD in male heroin-dependents at the trend level 10R allele of 5-HTTVNTR and 9R allele of DATVNTR positively associated with higher risk of co-occurring ASPD in male heroin-dependents	Yang et al., 2012 [16]
Dopamine D2 receptor  TaqI	115 male alcohol-dependents, 114 controls	Student’s t-test, regression	Interaction between A1 allele and harm-avoidance have a significant effect on predicting the number of ASPD symptoms	Bau et al., 2000 [17]
	103 male alcohol-dependents	χ2	A1 allele carriers have a higher prevalence of ASPD	Ponce et al., 2003 [18]
synaptosomal-associated protein 25  DdeI  MnlI	91 male offenders, 38 healthy controls	ANOVA	MnlI T/T and DdeI T/T genotypes more frequent in males with ASPD than in normal controls	Basoglu et al., 2011 [19]
Adenosine triphosphate-binding cassette, sub-family B, member 1  rs4728702	1379 (739 males) participants	Genome-wide complex trait analysis	Associated with adult antisocial behavior	Salvatore et al., 2015 [20]

Note: ASPD, antisocial personality disorder; CACNA1C, voltage-dependent L-type Ca²⁺ channel, alpha 1C subunit; DATVNTR, dopamine transporter variable number of tandem repeats; MMPI, Minnesota Multiphasic Personality Inventory; SPQ, Schizotypal Personality Questionnaire; STQ, Schizotypal Traits Questionnaire; 5-HTTLPR, serotonin-transporter gene-linked polymorphic region; 5-HTTVNTR, serotonin transporter introns 2 variable number of tandem repeats