Schizoid personality disorder

Schizoid personality disorder

Schizoid personality disorder is a personality disorder characterized by a lack of interest in social relationships, a tendency towards a solitary lifestyle, secretiveness, emotional coldness, and sometimes apathy, with a simultaneous rich, elaborate, and exclusively internal fantasy world...

 and avoidant personality disorder

Avoidant personality disorder

Avoidant personality disorder is a personality disorder recognized in the Diagnostic and Statistical Manual of Mental Disorders handbook in a person characterized by a pervasive pattern of social inhibition, feelings of inadequacy, extreme sensitivity to negative evaluation, and avoidance of...

 have both been associated with the same polymorphism

Polymorphism

Polymorphism or dimorphism may refer to:-Biology:* Polymorphism , including:** having multiple phenotypes within a population; the switch that determines which phenotype an individual displays can be genetic or environmental...

 within the ANKK1

ANKK1

The ANKK1 gene is a member of an extensive family of proteins involved in signal transduction pathways. This gene contains a single nucleotide polymorphism that causes an amino acid substitution within the 11th of 12 ankyrin repeats of ANKK1...

 gene. It remains unclear if these two personality disorders are linked to genetically distinct, but overlapping, personality disorders or if these two personality disorders are merely two different phenotypic expressions of the same genetic disorder.