Additional evidence that genetic variation of MAO-A gene supports a gendersubtype in obsessive-compulsive disorder

Studies have recently reported a sexually dimorphic association between obs essive-compulsive disorder (OCD) and a polymorphism related with variations in MAO-A activity. These observations suggest the possibility of gender di fferences in genetic susceptibility for OCD. We thus reexamined the MAO-a/E coRV polymorphism in a sample of 122 OCD patients and 124 healthy subjects, An excess of allele 1 in OCD females with major depression disorder was co nfirmed as previously reported. This difference was more strongly associate d with OCD females than males in the total sample, Finally, we analyzed a s ample of 51 OCD trios. Haplotype-based haplotype relative risk (HHRR) analy sis of the inheritance of the MAO-A variants revealed in the female proband s that 14 out of 19 transmitted the allele 1, providing significant evidenc e for an allelic association between OCD and MAO-A gene, In conclusion our findings may provide molecular evidence to identify a clinically meaningful gender subtype. However, an effort should be made to replicate the analysi s' in larger samples of informative parents using strategies such as transm ission disequilibrium test to allow definite conclusions. (C) 2001 Wiley-Li ss, Inc.