MAOA haplotypes associated with thrombocyte-MAO activity
- Equal contributors
1 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
2 Center for Genomics and Bioinformatics, Karolinska Institutet, Stockholm, Sweden
3 Departments of Genetics, Psychiatry & Epidemiology, University of North Carolina at Chapel Hill, NC, USA
4 Department of Neuroscience, Uppsala University, Uppsala, Sweden
5 Department of Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
6 Department of Psychology, University of Southern California, Los Angeles, USA
BMC Genetics 2005, 6:46 doi:10.1186/1471-2156-6-46Published: 20 September 2005
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).
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.
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.