Methylation of the dopamine D2 receptor (DRD2) gene promoter in women with a bulimia-spectrum disorder: associations with borderline personality disorder and exposure to childhood abuse.

Objective: Previous findings indicate that women with Bulimia Nervosa (BN), when compared to women with no eating disorder (NED), tend to display elevated methylation in the promoter region of the DRD2 gene. The preceding would be compatible with evidence of generally reduced dopamine activity in people with BN. However, altered DNA methylation has also been associated with adverse environmental exposures (such as to childhood abuse) and with psychiatric disturbances (such as Borderline Personality Disorder: BPD).

Differential association between the norepinephrine transporter gene and ADHD: role of sex and subtype.

Background: Pharmacologic and animal studies have strongly implicated the norepinephrine transporter (NET) in the pathophysiology of attention-deficit/hyperactivity disorder (ADHD). We conducted a family-based study, with stratification based on sex and subtype, to test the association between 30 tag single-nucleotide polymorphisms (SNPs) within the gene encoding NET (SLC6A2) and ADHD.

Methods: Family-based association tests were conducted with the categorical diagnosis of ADHD, as well as quantitative phenotypes of clinical relevance (Conners Global Index for Teachers and Parents, and Child Behavior Checklist measures).

No association between the DRD3 Ser9Gly polymorphism and schizophrenia.

Objective: To investigate the association between a Ser9Gly polymorphism of the dopamine D3 receptor gene (DRD3) and schizophrenia.

Methods: 408 schizophrenic patients and 172 control subjects were compared with regard to their DRD3 Ser9Gly genotypic and allelic frequencies. In addition, we carried out a family-based association study including 183 pedigrees (472 subjects) using the transmission disequilibrium test (TDT).