Polygenic risk score comparator (PRScomp): Test population vs. worldwide populations.

BACKGROUND: Polygenic risk scores (PRS) are a powerful tool for predicting an individual's genetic risk for complex diseases. METHODS: We have developed a web service (PRScomp) as a user-friendly tool to evaluate PRS of the user own population and compare it with worldwide populations. RESULTS: A disease/trait database has been constructed from GWAS Catalog summary statistics. Genotype data of test population is uploaded and merged with the reference dataset (1000 Genome Project and Human Genome Diversity Project) to obtain a file including the common SNPs. The user can select a disease/trait from the database and a curated set of risk markers is used to calculate summatory PRS. Distribution of z-scored PRS values is presented in publication-ready plots and text files that can be downloaded. DISCUSSION: PRScomp can be useful for public health decision-making by identifying population-specific genetic risk factors and informing the development of targeted interventions for at-risk populations.

An Integral Approach to the Molecular Diagnosis of Tuberous Sclerosis Complex: The Role of Mosaicism and Splicing Variants.

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder characterized by the presence of hamartomas in multiple organs. At the molecular level, the disease is caused by pathogenic variants in the TSC1 and TSC2 genes, and only 10% to 25% of clinically diagnosed patients remain negative after multiplex ligation-dependent probe amplification and exon sequencing of both genes. Here, to improve the molecular diagnosis of TSC, we developed an integral approach that includes multiplex ligation-dependent probe amplification and deep-coverage next-generation sequencing of the entire TSC1 and TSC2 genes, along with an adapted bioinformatic pipeline to detect variants at low allele frequencies (>1%). Using this workflow, the molecular cause was identified in 29 of 42 patients with TSC, describing here, for the first time, 12 novel pathogenic variants in TSC genes. These variants included seven splicing variants, five of which were studied at the cDNA level, determining their effect on splicing. In addition, 8 of the 29 pathogenic variants were detected in mosaicism, including four patients with previous negative study results who presented extremely low mosaic variants (allele frequency, <16%). We demonstrate that this integral approach allows the molecular diagnosis of patients with TSC and improves the conventional one by adapting the technology to the detection of low-frequency mosaics.

The efficacy of combining topiramate and 4-aminopyridine to reduce relapses and interictal progression in two cases of episodic ataxia type 2.

BACKGROUND: Episodic ataxia type 2 is an autosomal dominant channelopathy, caused by genetic variants in the voltage-dependent calcium channel a-1 subunit (CACNA1A), which is characterized by intermittent episodes of vertigo and ataxia. A slow progression of cerebellar signs is commonly observed in the course of the disease. Treatment with the carbonic anhydrase inhibitor acetazolamide is recommended. METHODS: We report the cases of two patients with EA-2 and migraine, linked to a novel CACNA1A mutation associated with disabling ictal and interictal disease, which did not respond to acetazolamide. RESULTS: A 30-year-old woman and a 50-year-old man, who was a ski instructor, reported disabling episodes of rotatory vertigo and progressive interictal ataxia. In both cases, the disease progressed despite treatment with acetazolamide. The concomitant use of topiramate and 4-aminopyridine significantly reduced the frequency and severity of relapses and migraine and improved the interictal cerebellar progression in both cases. CONCLUSIONS: We propose combined applications of topiramate and 4-aminopyridine in refractory cases and those with poor tolerance to acetazolamide and also in those with frequent associated migraine. The effectiveness of this combination of drugs for treating intermittent ataxic episodes and interictal signs in EA-2 has not been previously reported.

Assessment of the Concordance and Diagnostic Accuracy Between Elecsys and Lumipulse Fully Automated Platforms and Innotest.

Manual ELISA assays are the most commonly used methods for quantification of biomarkers; however, they often show inter- and intra-laboratory variability that limits their wide use. Here, we compared the Innotest ELISA method with two fully automated platforms (Lumipulse and Elecsys) to determine whether these new methods can provide effective substitutes for ELISA assays. We included 149 patients with AD (n = 34), MCI (n = 94) and non-AD dementias (n = 21). Aß42, T-tau, and P-tau were quantified using the ELISA method (Innotest, Fujirebio Europe), CLEIA method on a Lumipulse G600II (Fujirebio Diagnostics), and ECLIA method on a Cobas e 601 (Roche Diagnostics) instrument. We found a high correlation between the three methods, although there were systematic differences between biomarker values measured by each method. Both Lumipulse and Elecsys methods were highly concordant with clinical diagnoses, and the combination of Lumipulse Aß42 and P-tau had the highest discriminating power (AUC 0.915, 95% CI 0.822-1.000). We also assessed the agreement of AT(N) classification for each method with AD diagnosis. Although differences were not significant, the use of Aß42/Aß40 ratio instead of Aß42 alone in AT(N) classification enhanced the diagnostic accuracy (AUC 0.798, 95% CI 0.649-0.947 vs. AUC 0.778, 95% CI 0.617-0.939). We determined the cut-offs for the Lumipulse and Elecsys assays based on the Aß42/Aß40 ratio ± status as a marker of amyloid pathology, and these cut-offs were consistent with those recommended by manufacturers, which had been determined based on visual amyloid PET imaging or diagnostic accuracy. Finally, the biomarker ratios (P-tau/Aß42 and T-tau/Aß42) were more consistent with the Aß42/Aß40 ratio for both Lumipulse and Elecsys methods, and Elecsys P-tau/Aß42 had the highest consistency with amyloid pathology (AUC 0.994, 95% CI 0.986-1.000 and OPA 96.4%) at the ≥0.024 cut-off. The Lumipulse and Elecsys cerebrospinal fluid (CSF) AD assays showed high analytical and clinical performances. As both automated platforms were standardized for reference samples, their use is recommended for the measurement of CSF AD biomarkers compared with unstandardized manual methods, such as Innotest ELISA, that have demonstrated a high inter and intra-laboratory variability.

T-Type Cav3.1 Channels Mediate Progression and Chemotherapeutic Resistance in Glioblastoma.

T-type Ca2+ channels (TTCC) have been identified as key regulators of cancer cell cycle and survival. In vivo studies in glioblastoma (GBM) murine xenografts have shown that drugs able to block TTCC in vitro (such as tetralol derivatives mibefradil/NNC-55-096, or different 3,4-dihydroquinazolines) slow tumor progression. However, currently available TTCC pharmacologic blockers have limited selectivity for TTCC and are unable to distinguish between TTCC isoforms. Here we analyzed the expression of TTCC transcripts in human GBM cells and show a prevalence of Cacna1g/Cav3.1 mRNAs. Infection of GBM cells with lentiviral particles carrying short hairpin RNA against Cav3.1 resulted in GBM cell death by apoptosis. We generated a murine GBM xenograft via subcutaneous injection of U87-MG GBM cells and found that tumor size was reduced when Cav3.1 expression was silenced. Furthermore, we developed an in vitro model of temozolomide-resistant GBM that showed increased expression of Cav3.1 accompanied by the activation of macroautophagy. We confirmed a positive correlation between Cav3.1 and autophagic markers in both GBM cultures and biopsies. Of note, Cav3.1 knockdown resulted in transcriptional downregulation of p62/SQSTM1 and deficient autophagy. Together, these data identify Cav3.1 channels as potential targets for slowing GBM progression and recurrence based on their role in regulating autophagy. SIGNIFICANCE: These findings identify Cav3.1 calcium channels as a molecular target to regulate autophagy and prevent progression and chemotherapeutic resistance in glioblastoma.

Minor Hallucinations in Alzheimer's Disease.

BACKGROUND: Hallucinations may have a broad spectrum and include so-called minor hallucinations (MHs). MHs include passage hallucinations (PHs), visual illusions, and presence hallucinations (PrHs). OBJECTIVE: To determine the prevalence and characteristics of MHs in Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) patients, and to describe their potential relationship with cognition, behavioral symptoms, and use of psychoactive drugs. METHODS: We have recruited prospectively and consecutively 268 subjects (90 AD mild-moderate drug-naïve patients, 78 aMCI, and 100 controls). All patients responded to a semi-structured questionnaire in order to rate psychotic phenomena. Clinical, neuropsychological, and demographic data of patients with and without MH were compared with those of age, sex, and education-matched controls. RESULTS: The prevalence of MHs was 21.1% (19) in AD, 12.8% (10) in aMCI, and 3% (3) in controls (p < 0.01). The most frequent MH was PrH (9.3%), followed by PH (4.9%) and illusion (0.7%). Eight (27.8%) patients had more than one MH. After adjusting for age and gender, there was a negative correlation between the presence of MHs and MMSE score (r = -0.261; p < 0.01) and a positive correlation between MHs and Neuropsychiatric Inventory score (r = 0.237; p < 0.01). We did not observe a significant relationship between presence of MHs and the consumption of psychoactive drugs (p > 0.05). CONCLUSION: We have shown that the presence of MHs in patients with newly diagnosed, untreated AD and aMCI is more than controls. MHs were correlated with other behavioral symptoms and a worse cognitive performance. We suggest the specific interrogation for MHs as a clinical feature for this population.

Utilidad de los nuevos criterios diagnósticos y la introducción de los biomarcadores en el continuum de la enfermedad de Alzheimer / Usefullness of new diagnosis criteria and introduction of biomarkers in Alzheimer’s disease continuum

Objetivos: los nuevos criterios diagnósticos de enfermedad de Alzheimer (EA) y deterioro cognitivo leve (DCL) apoyan la utilización de los biomarcadores. Valoramos la utilidad de añadir los biomarcadores en la práctica clínica habitual para confirmar y/o modificar el grado de certeza en el diagnóstico de EA y DCL. Pacientes y métodos: presentamos 40 pacientes en los que de forma consecutiva se realizó la determinación de biomarcadores en líquido cefalorraquídeo (LCR) (amilode, tau y p-tau) y evaluación neuropsicológica según los criterios establecidos en nuestra unidad. Resultados: presentamos las características demográficas de los pacientes. En el 52 % de los pacientes los biomarcadores permitieron modificar el grado de certeza del diagnóstico. La mayor aportación es poder reclasificar a los pacientes con DCL en pacientes con DCL y alto riesgo de EA (7), riesgo intermedio (6) o riesgo bajo (12). En dos casos de inicio rápidamente progresivo, los biomarcadores fueron compatibles con EA. Además, su determinación basal ayuda a predecir el riesgo de progresión a EA tras 2 años de seguimiento. Conclusiones: la utilización de los biomarcadores en la práctica clínica habitual ayuda a modificar el grado de certeza del diagnóstico clínico y, por tanto, el pronóstico de los pacientes, especialmente en fase prodrómica y en presentaciones atípicas (AU)

Background: The new diagnostic criteria for Alzheimer's disease (AD) and mild cognitive impairment (MCI) supports the use of biomarkers. We appreciate the value of adding biomarkers to routine clinical practice to confirm and/or modify the degree of certainty in the diagnosis of AD and MCI. Methods: We present 40 patients consecutively determining CSF biomarkers (amyloid, tau and p-tau) and neuropsychological evaluation was performed according to the criteria set out in our unit. Results: We present the demographic characteristics of the patients. In 52% of patients allowed biomarkers modify the degree of certainty of the diagnosis. The greatest contribution is to reclassify patients with MCI in MCI patients at high risk of AD (7), intermediate risk (7) or low risk of AD (12). In both cases of rapidly progressive onset biomarkers were consistent with AD. Besides, basal CSF biomarkers are useful to predict progression to AD after two years follow-up. Conclusion: The use of biomarkers in clinical practice helps to modify the degree of certainty of the clinical diagnosis, and therefore the prognosis of patients, especially in prodromal phase and atypical presentations (AU)