Laila Cigana Schenkel

The BDNF Val66Met polymorphism is an independent risk factor for high lethality in suicide attempts of depressed patients

Some authors have reported an association of BDNF Val66Met polymorphism with suicidal behavior and/or clinical aspects of suicidal attempts. We evaluated, here, the impact of BDNF Val66Met polymorphism on the clinical characteristics of suicide attempts. The study was conducted on a cohort of 120 consecutive patients who were admitted to the Emergency Hospital of Porto Alegre, Brazil, due to a suicide attempt. Variables of univariate analyses were included in a logistic regression model to test whether the risk factors had independent effect. In univariate analyses, sex, BDNF genotype, intent and method of suicide attempt were all risk factors for high lethality in suicide attempts. After logistic regression analysis, male sex (O.R.=3.03; 95% C.I=1.34-6.84; 0.008) and the presence of BDNF 66Met allele (O.R.=2.62; 95% C.I=1.04-6.57; 0.04) were significantly and independently associated with the high lethality in suicide attempts. The present study showed that BDNF 66Met allele is an independent predictor of high lethality in suicide attempts of depressed patients. This finding is important because it might allow earlier identification of patients at high risk for suicide, perhaps providing better tools for clinical care of these patients in the future.

Serotonin gene polymorphisms and psychiatry comorbidities in temporal lobe epilepsy

OBJECTIVE Neuropsychiatric comorbidities are frequent in temporal lobe epilepsy (TLE). It is biologically plausible that alterations in serotonin-related genes may be involved in higher susceptibility to psychiatric disease in these individuals. Here we report results of an association study of serotonin gene polymorphisms and psychiatry comorbidities in TLE. METHODS Case-control study of 155 patients with temporal lobe epilepsy. We evaluate the influence of 5-HTTLPR and 5-HTTVNTR polymorphisms in the 5-HTT gene and the C-1019G polymorphism in the 5-HT1A gene in psychiatric comorbidities of TLE. RESULTS After logistic regression, female sex (OR=2.34; 95% CI 1.06-5.17; p=0.035) and the presence of C allele of 5-HT1A C-1019G polymorphism (OR=2.77; 95% CI 1.01-7.63; p=0.048) remained independent risk factors for anxiety disorders in temporal lobe epilepsy. CONCLUSION C allele of 5-HT1A C-1019G polymorphism might be an independent risk factor for anxiety disorders in temporal lobe epilepsy. We believe that other studies in this venue will shade some light on molecular mechanisms involved in psychiatric comorbidities in epilepsy.

Serotonin transporter gene (5HTT) polymorphisms and temporal lobe epilepsy.

OBJECTIVE Preclinical and clinical studies have shown that serotonin levels might modulate susceptibility to seizures. Here we evaluated an association between 5HTTLPR and 5HTTVNTR allele variants in serotonin transporter gene and epileptogenesis in temporal lobe epilepsy (TLE). METHODS A case-control candidate gene study evaluating the frequencies of 5HTTLPR biallelic and 5HTTVNTR allele variants in patients and healthy subjects. Genotypes were grouped according to transcriptional efficiency. Cases were 175 patients with TLE selected from the Epilepsy Outpatient Clinic of Hospital de Clínicas de Porto Alegre, classified according to the electroclinical classification of the ILAE and neuroimaging findings. The control group consisted of 155 healthy unrelated subjects selected from the same population. RESULTS We observed that less efficient transcriptional genotypes for 5-HTT polymorphisms were more frequent in epileptic patients (O.R.=3.24; 95% C.I.=1.08-9.73; p=0.036). Our results suggest that less efficient transcriptional genotypes for serotonin transporter gene are associated with TLE. CONCLUSION In this study we observed an association between the presence of 5HTTLPR and 5-HTTVNTR less transcriptional efficient combined genotypes and TLE. Our results suggest that modulation of the serotoninergic system might be implied in epileptogenesis in TLE.

No major clinical impact of Val66Met BDNF gene polymorphism on temporal lobe epilepsy

OBJECTIVE To report the frequencies of Val66Met polymorphism in patients with temporal lobe epilepsy (TLE) compared to normal controls. We also investigated whether Val66Met promoted differences in major clinical variables of TLE. METHODS A case-control study comparing the frequencies of Val66Met polymorphism in 101 Caucasian TLE patients and in 104 Caucasian normal matching controls. In the second step, we evaluated the patient group in terms of the major clinical and electrographic variables related to the epileptogenic process. RESULTS The frequency of Val66Met polymorphism did not differ between epileptic patients and normal controls. Moreover, the Val66Met polymorphisms did not influence age of epilepsy onset, duration of epilepsy, control of seizures, or extension of the irritative zone. Also, the groups did not differ in terms of family history of epilepsy and presence of aura. CONCLUSION In spite of abundant evidence that Val66Met BDNF polymorphism has an impact on several different neurological or psychiatric disorders, we conclude that a major clinical impact of Val66Met polymorphism as a disease modifier in temporal lobe epilepsy is probably unlikely.

Response to: A functional 5-HT1A variant and comorbid anxiety

We thank Dr. Philipp Sand for his interest in our manuscript and we apologize for the missing information. In our work we employed an allele-specific polymerase chain reaction (PCR) amplification adapted from Parsey et al. (2006), which was performed in a final 12.5 l reaction mixture containing 1× PCR buffer (Invitrogen), 100 ng DNA, 1.6 mM MgCl2 (Invitrogen), 0.8% of Q-solution (QIAGEN), 0.2 mM dNTP, 0.75 U Taq polymerase (Invitrogen), and 5 pm of each primer. Each sample was amplified in two separate reactions using the set of primers as presented in Table 1, and described by Wu and Comings (1999). The reaction conditions were 94 ◦C for 5 min, 40 cycles at 94 ◦C for 30 s, 55 ◦C for 30 s, 72 ◦C for 30 s and a final extension step at 72 ◦C