MAOA haplotypes associated with thrombocyte-MAO activity.
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.
Jansson
Mårten
M
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. marten.jansson@cmm.ki.se
McCarthy
Shane
S
Sullivan
Patrick F
PF
Dickman
Paul
P
Andersson
Björn
B
Oreland
Lars
L
Schalling
Martin
M
Pedersen
Nancy L
NL
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
D008995:Monoamine Oxidase