Use of "omics" technologies to dissect neurologic disease.

Over the past 5 years, the advent of massively parallel technologies for understanding disease at the molecular level accompanied by simultaneous rapid development of the computational tools needed to analyze and filter such data has revolutionized medical science. These "next-generation" "omics" technologies include next-generation sequencing technology for detection of disease-associated DNA sequence variants, RNA sequencing for transcriptome and noncoding RNA analysis, quantitative detection of epigenomic dynamics, and chromatin immunoprecipitation sequencing analysis for DNA-protein interactions, interactome analysis for networks formed by protein-protein interactions, and metabolome analysis for metabolic systems. The analysis and integration of data derived from massively parallel technologies will significantly deepen our understanding of human disease, will inform functional studies, in vitro and in vivo model generation, and will advance the development of improved, personalized diagnostic tools and more effective therapeutic targets. In this chapter we review the classic genomic approaches for identifying mechanisms underlying human disease, and summarize the emerging "omics" technologies allowing massively parallel interrogation of biologic systems.

Neuropsychological predictors of rapidly progressive Alzheimer's disease.

OBJECTIVE: Alzheimer's disease (AD), the most common cause of dementia, typically shows a slow clinical progression over time. 'Rapidly progressive' AD, a variant of the disease characterized by an aggressive course, exhibits distinct clinical, biological, and neuropathological features. Here, we investigate neuropsychological predictors of rapid decline in a group of mild patients with AD. METHODS: One hundred fifty-three mild patients with AD admitted to a memory disorder clinic and followed for up to 3 years were included in this study. A comprehensive neuropsychological (NP) battery was performed at the time of enrollment. Patients were defined as 'rapidly progressive' if they exhibited a drop of 6 or more points on the Mini Mental State Examination (MMSE) between two consecutive annual visits. This event defined the main outcome in multiple analyses of variance and Cox proportional hazards models that investigated the impact of NP predictors. Categorical principal component analysis (CATPCA) was also employed in order to delineate clusters of NP tests and to test their effect on the outcome. RESULTS: Of 153 subjects, thirty-seven (24%) were classified as 'rapidly progressive'; those subjects showed younger age of symptoms onset compared to slow decliners (68 vs 71.5 years old). Baseline lower performance on a neuropsychological test of naming predicted a rapid decline over the follow-up (P = 0.001). Three clusters of NP were defined by CATPCA: (i) executive/language, (ii) visuospatial memory, and (iii) verbal memory. The executive/language component predicted a rapid decline over the follow-up (P = 0.016). CONCLUSION: Early executive/language impairment is highly predictive of a rapid progression of AD.

Binge eating and fast cognitive worsening in an early-onset bvFTD patient carrying C9ORF72 expansion.

An expanded hexanucleotide (GGGGCC) repeat in a non-coding promoter region of open reading frame 72 of chromosome 9 (C9ORF72) has been recently identified as a major cause of familial and sporadic frontotemporal lobar degeneration. We describe the clinical picture of a 64-year-old woman carrying the hexanucleotide repeat expansion, who developed a sporadic early-onset form of behavioral variant frontotemporal dementia characterized by the occurrence of uncommon behavioral manifestations such as binge eating disturbance and by a rapid worsening of cognitive abilities. Our report confirms previous studies asserting that C9ORF72 repeats may sustain heterogeneous clinical syndromes.

Independent and epistatic effects of variants in VPS10-d receptors on Alzheimer disease risk and processing of the amyloid precursor protein (APP).

Genetic variants in the sortilin-related receptor (SORL1) and the sortilin-related vacuolar protein sorting 10 (VPS10) domain-containing receptor 1 (SORCS1) are associated with increased risk of Alzheimer's disease (AD), declining cognitive function and altered amyloid precursor protein (APP) processing. We explored whether other members of the (VPS10) domain-containing receptor protein family (the sortilin-related VPS10 domain-containing receptors 2 and 3 (SORCS2 and SORCS3) and sortilin (SORT1)) would have similar effects either independently or together. We conducted the analyses in a large Caucasian case control data set (n=11,840 cases, 10,931 controls) to determine the associations between single nucleotide polymorphisms (SNPs) in all the five homologous genes and AD risk. Evidence for interactions between SNPs in the five VPS10 domain receptor family genes was determined in epistatic statistical models. We also compared expression levels of SORCS2, SORCS3 and SORT1 in AD and control brains using microarray gene expression analyses and assessed the effects of these genes on γ-secretase processing of APP. Several SNPs in SORL1, SORCS1, SORCS2 and SORCS3 were associated with AD. In addition, four specific linkage disequilibrium blocks in SORCS1, SORCS2 and SORCS3 showed additive epistatic effects on the risk of AD (P≤0.0006). SORCS3, but not SORCS2 or SORT1, showed reduced expression in AD compared with control brains, but knockdown of all the three genes using short hairpin RNAs in HEK293 cells caused a significant threefold increase in APP processing (from P<0.001 to P<0.05). These findings indicate that in addition to SORL1 and SORCS1, variants in other members of the VPS10 domain receptor family (that is, SORCS1, SORCS2, SORCS3) are associated with AD risk and alter APP processing. More importantly, the results indicate that variants within these genes have epistatic effects on AD risk.

Efficacy of sertraline in a patient with Neuro-Beçhet's disease.

Behçet's disease (BD) is a heterogeneous multisystem inflammatory disorder of unknown etiology, of which the involvement of the central nervous system is a serious manifestation (Neuro-Behçet's syndrome, NBS). We report a 65-year-old patient who presented with a progressive cognitive impairment and behavioral disturbances (depression and apathy). He fulfilled the International Study Group criteria for BD. Treatment with sertraline was then commenced with an objective improvement of his cognitive and behavioral status. The current report describes a patient with an extensive history of NBS (almost 20 years) and a possible therapeutic option for behavioral impairment.

Restless legs syndrome in a group of patients with Alzheimer's disease.

BACKGROUND: Restless legs syndrome (RLS) is a neurological disorder characterized by the urge to move the legs associated with peculiar unpleasant sensations during periods of rest and inactivity that are relieved by movement. A few studies analyzed RLS in neurodegenerative diseases such as Alzheimer's Disease (AD). The aim of our study was to assess the prevalence and the clinical characteristics of RLS in a cohort of AD patients. METHODS: Three hundred and thirty-nine subjects with a diagnosis of AD were recruited. Cognitive, functional, and neuropsychiatric measures were collected at baseline and six-monthly for a 2-years follow-up RESULTS: Fourteen subjects met the RLS criteria. RLS subjects were more frequently male (p:0,006) and younger than AD subject without RLS (p:0,029). MMSE, ADL and IADL were not significantly different. NPI total scores did not differ significantly, however, AD patients with RLS were found to be more apathetic (p:0,001) than AD subjects without RLS. CONCLUSION: RLS prevalence in our AD cohort was estimated to be about 4%. RLS appeared to be associated with neuropsychiatric symptoms such as apathy. RLS and apathy might share a common pathophysiological basis represented by a dysfunction of the central dopaminergic system.

Genome-wide haplotype association study identifies the FRMD4A gene as a risk locus for Alzheimer's disease.

Recently, several genome-wide association studies (GWASs) have led to the discovery of nine new loci of genetic susceptibility in Alzheimer's disease (AD). However, the landscape of the AD genetic susceptibility is far away to be complete and in addition to single-SNP (single-nucleotide polymorphism) analyses as performed in conventional GWAS, complementary strategies need to be applied to overcome limitations inherent to this type of approaches. We performed a genome-wide haplotype association (GWHA) study in the EADI1 study (n=2025 AD cases and 5328 controls) by applying a sliding-windows approach. After exclusion of loci already known to be involved in AD (APOE, BIN1 and CR1), 91 regions with suggestive haplotype effects were identified. In a second step, we attempted to replicate the best suggestive haplotype associations in the GERAD1 consortium (2820 AD cases and 6356 controls) and observed that 9 of them showed nominal association. In a third step, we tested relevant haplotype associations in a combined analysis of five additional case-control studies (5093 AD cases and 4061 controls). We consistently replicated the association of a haplotype within FRMD4A on Chr.10p13 in all the data set analyzed (OR: 1.68; 95% CI: (1.43-1.96); P=1.1 × 10(-10)). We finally searched for association between SNPs within the FRMD4A locus and Aß plasma concentrations in three independent non-demented populations (n=2579). We reported that polymorphisms were associated with plasma Aß42/Aß40 ratio (best signal, P=5.4 × 10(-7)). In conclusion, combining both GWHA study and a conservative three-stage replication approach, we characterised FRMD4A as a new genetic risk factor of AD.

Serotonin toxicity: a short review of the literature and two case reports involving citalopram.

The serotonin toxicity (ST) is a potentially life-threatening adverse drug reaction results from therapeutic drug use, intentional self-poisoning, or inadvertent interactions between drugs. ST can be caused by a single or a combination of drugs with serotonergic activity due to excessive serotonergic agonism on central nervous system and peripheral serotonergic receptors (monoamine oxidase inhibitors, tricyclic antidepressants, SSRIs, opiate analgesics, over-the-counter cough medicines, antibiotics, weight-reduction agents, antiemetics, antimigraine agents, drugs of abuse, H2-antagonist and herbal products). The serotonin toxicity is often described as a clinical triad of mental-status changes (agitation and excitement with confusion), autonomic hyperactivity (diaphoresis, fever, tachycardia, and tachypnea), neuromuscular abnormalities (tremor, clonus, myoclonus, and hyperreflexia) and, in the advanced stage, spasticity; not all of these findings are consistently present. In this article, we describe two cases of ST due to interaction between Citalopram and two CYP2D6 inhibitors: Cimetidine and Topiramate and their clinical resolution after treatment discontinuation.