Study Report

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Basic Info

Reference	Pandolfo, G., 2015 PMID: 25766270
Citation	Pandolfo, G., et al. (2015). "Association of the COMT synonymous polymorphism Leu136Leu and missense variant Val158Met with mood disorders." J Affect Disord 177: 108-113.
Disease Type	Bipolar Disorder & Major Depressive Disorder
Study Design	case-control
Study Type	candidate-gene association study
Sample Size	54 BD patients, 58 MDD patients, 58 controls
Predominant Ethnicity
Population	Sicilian
Gender	45.7% male patients of MDD, 38.6% male patients of BD, 37.9% male controls
Age Group	adults : mean age=51.6, SD=11.4 years of MDD patients, mean age=47.8, SD=10 years of BD patients, mean age=48.7, SD=10 years of controls

Detail Info

Sample Diagnosis	DSM-IV
Sample Status	One hundred and twelve Sicilian subjects with affective disorders, afferent as outpatients to the Psychiatry Unit of the University Hospital of Messina (Italy). Fifty-four patients met DSM-IV criteria for major depressive disorder and 58 patients for bipolar disorder. All patients were receiving antidepressant medications.
Technique	genotyping
Statistical Method	Data obtained from the study underwent check and quality control and, subsequently, descriptive and inferential statistical analysis.Continuous data were expressed as mean +-SD and comparison among the groups was performed using a one way analysis of variance(one way ANOVA) followed by Bonferroni's posthoc test, or Student's T test, when appropriated. Non-continuous data were expressed aspercentages, and the comparison among the groups was performed by using the Chi-Square for genotype and Fisher test for the diplotype analysis. Statistical analysis was performed with SPSS16.0 software. Post-hocpower (PHP)of the study was estimated using PS software (version3.1.2).
Result Summary	We did not find significant differences in the Val158Met variant distribution between patients and controls. Instead, we found that the C1886 major allele and the CC1886 wild-type genotype frequencies were significantly higher in controls than in both groups of patients. On the contrary, the G1886 minor allele and the heterozygous CG1886 genotype were significantly more present in both MDD and BD patients than in healthy subjects. When looking at combined polymorphisms, we found a significantly higher frequency of the double heterozygous diplotype CG/GAVal/Met158 in both MDD and BD patients than in controls. Instead, the diplotype CC/GAVal/Met158 showed a significantly higher frequency in controls than in BD patients. LIMITATIONS: The small size of our study cohort may limit the generalizability of the present findings. This work first showed the association of combined Leu136Leu and Val158Met variants of COMT gene with MDD and BD.

Genetic factors reported by this study for BD

Other variants reported by this study for BD (count: 2)

Variant Name	Related Gene	Type	Allele Change	Risk Allele	Statistical Values	Author Comments	Result Category
COMT G1947A	COMT	point mutation	G/A		P-value=1 for Val/Val158, P-value=0.351 for Val/Met158, P-value=0.272 for Met/Met158, allelic P-value=0.51	The Val/Met158 genotype was the most represented in all thre...... The Val/Met158 genotype was the most represented in all three groups, with higher frequencies in MDD and BD patients than incontrols, while the Met/Met158 mutated genotype was morefrequent in healthy subjects than inpatients. However, thesedifferences did not reach statistically significant values. The resultsof posthoc power analysis showed that the study was insufficientlypowered to detect the true association of G1947A(Val158-Met) variant of COMT gene with MDD and BD, if existent in these populations. More...	Negative
COMT C1886G	COMT	point mutation	C/G		P-value=0.005 for CC1886, P-value=0.014 for CG1947, P-value=0.568 for GG1947, allelic P-value=0.017	The C1886 major allele was the most represented in all group...... The C1886 major allele was the most represented in all groups, and its frequency was significantly higher in healthy subjects than in both groups of patients. The frequency of the G1886 minor allele was significantly higher in both MDD and BD patients than in healthy subjects. More...	Positive

Genes reported by this study for BD (count: 1)

Gene	Statistical Values/Author Comments	Result Category
COMT	This work first showed the association of combined Leu136Leu and Val158Met variants of COMT gene wit...... This work first showed the association of combined Leu136Leu and Val158Met variants of COMT gene with MDD and BD. More...	Positive

Genetic factors reported by this study for SZ and/or MDD

Other variants reported by this study for SZ/MDD

Disease	Variant Name	Related Gene	Type	Statistical Values	Description	Result Category
MDD	COMT G1947A	COMT	point mutation	P-value=0.794 for Val/Val158, P-value=0.471 for Val/Met158, P-value=0.256 for Met/Met158, allelic P-value=0.393	The Val/Met158 genotype was the most represented in all three groups, with higher frequencies in MDD and BD patients than incontrols, while the Met/Met158 mutated genotype was morefrequent in healthy subjects than inpatients. However, thesedifferences did not reach statistically significant values. The resultsof posthoc power analysis showed that the study was insufficientlypowered to detect the true association of G1947A(Val158-Met) variant of COMT gene with MDD and BD, if existent in these populations.	Negative
MDD	COMT C1886G	COMT	point mutation	P-value=0.002 for CC1886, P-value=0.025 for CG1947, P-value=0.216 for GG1947, allelic P-value=0.003		Positive

Genes reported by this study for SZ/MDD

Disease	Gene	Description	Result Category
MDD	COMT	This work first showed the association of combined Leu136Leu and Val158Met variants of COMT gene with MDD and BD.	Positive