Genes linked to psychopathy

Psychopathy has a polygenic basis, with six genes having been shown particular significance regarding the risk: ANKK1, DRD2, DRD4, COMT, MAOA, and SLC6A4 (particularly the 5-HTTLPR variant). Other notable genetic risk factors for becoming a psychopath include alleles of OXTR, AVPR1A, CADM2, PRKG1, and NR3C1. Several of these genes, like COMT, MAOA, 5-HTTLPR, OXTR, and NR3C1, undergo direct epigenetic modification following trauma. Psychopathy is principally a personality construct used by psychologists to explain and predict behavior, but it may also be viewed as a spectrum of traits related to atypical patterns of neurodevelopment.

The expression of psychopathy-related phenotypes depends on the combination of inherited alleles, in addition to environmental factors. Individuals are at an elevated risk of psychopathic traits if they inherit multiple core alleles located at different loci, likely at least four core alleles at a minimum of three different loci. This is similar to many other spectrum disorders, such as schizotypy, which typically involve a complex interaction between genes and environmental factors.

Genes linked to psychopathy
Loci					Characteristics
ANKK1	DRD2	MAOA	COMT	5-HTTLPR	Basal endophenotype	Also associated with
Taq1 A2 allele	957T allele				calm
Taq1 A1 allele	957C allele				anxious	posttraumatic stress disorder
	957C/C genotype				impulsive	schizophrenia
Taq1 A1 allele	957C/C genotype				dissocial	dissocial personality disorder
		low activity
			low activity
				long
Taq1 A1 allele	957C/C genotype	low activity			dissocial	antisocial personality disorder
Taq1 A1 allele	957C/C genotype		low activity		dissocial	borderline personality disorder
Taq1 A1 allele	957C/C genotype			long	dissocial	narcissistic personality disorder
Taq1 A1 allele	957C/C genotype	low activity	low activity		dissocial	sadistic personality disorder
Taq1 A1 allele	957C/C genotype	low activity		long	dissocial	histrionic personality disorder
Taq1 A1 allele	957C/C genotype		low activity	long	dissocial	Munchausen by proxy
Taq1 A1 allele	957T allele		low activity	long	anxious	Munchausen syndrome

DRD2

In addition to the DRD2 957C/C genotype, the DRD2 Taq1 B allele and polymorphisms in the promoter region of the DRD4 gene have also have been linked to psychopathy. This suggests that the dissocial and impulsive basal endophenotypes can be subdivided into at least seven subtypes: 1a, 1b, 1c, 2, 3a, 3b, and 3c.

Impulsive/dissocial subtypes
DRD2		DRD4	Subtype
957 locus	Taq1 B locus	-616 locus	Subtype
C/C genotype	B1 allele-negative	-616G allele	1a
T allele	B1 allele-positive	-616G allele	1b
C/C genotype	B1 allele-positive	-616G allele	1c
T allele	B1 allele-negative	-616C/C genotype	2
C/C genotype	B1 allele-negative	-616C/C genotype	3a
T allele	B1 allele-positive	-616C/C genotype	3b
C/C genotype	B1 allele-positive	-616C/C genotype	3c

Genes linked to psychopathy

DRD2

Further reading