title: MAOA haplotypes associated with thrombocyte-MAO activity.
abstract: BACKGROUND
  The aim was to ascertain whether thrombocyte MAO (trbc-MAO) activity and depressed state are genetically associated with the MAO locus on chromosome X (Xp11.3 - 11.4). We performed novel sequencing of the MAO locus and validated genetic variants found in public databases prior to constructing haplotypes of the MAO locus in a Swedish sample (N = 573 individuals).
  
  
  RESULTS
  Our results reveal a profound SNP desert in the MAOB gene. Both the MAOA and MAOB genes segregate as two distinct LD blocks. We found a significant association between two MAOA gene haplotypes and reduced trbc-MAO activity, but no association with depressed state.
  
  
  CONCLUSIONS
  The MAO locus seems to have an effect on trbc-MAO activity in the study population. The findings suggest incomplete X-chromosome inactivation at this locus. It is plausible that a gene-dosage effect can provide some insight into the greater prevalence of depressed state in females than males.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. marten.jansson@cmm.ki.se
authors.forename: Mårten
authors.initials: M
authors.lastname: Jansson
authors.forename: Shane
authors.initials: S
authors.lastname: McCarthy
authors.forename: Patrick F
authors.initials: PF
authors.lastname: Sullivan
authors.forename: Paul
authors.initials: P
authors.lastname: Dickman
authors.forename: Björn
authors.initials: B
authors.lastname: Andersson
authors.forename: Lars
authors.initials: L
authors.lastname: Oreland
authors.forename: Martin
authors.initials: M
authors.lastname: Schalling
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Pedersen
mesh_terms: D001792:Blood Platelets / Q000201:enzymology*; D003863:Depression / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D006239:Haplotypes; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D008995:Monoamine Oxidase / Q000235:genetics* / Q000378:metabolism; D005810:Multigene Family; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology; D049951:X Chromosome Inactivation
chemical_list: D008995:Monoamine Oxidase