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The CAM-S: development and validation of a new scoring system for delirium severity in 2 cohorts

Mon, 08/24/2015 - 2:24pm

BACKGROUND: Quantifying the severity of delirium is essential to advancing clinical care by improved understanding of delirium effect, prognosis, pathophysiology, and response to treatment.

OBJECTIVE: To develop and validate a new delirium severity measure (CAM-S) based on the Confusion Assessment Method.

DESIGN: Validation analysis in 2 independent cohorts.

SETTING: Three academic medical centers.

PATIENTS: The first cohort included 300 patients aged 70 years or older scheduled for major surgery. The second included 919 medical patients aged 70 years or older.

MEASUREMENTS: A 4-item short form and a 10-item long form were developed. Association of the maximum CAM-S score during hospitalization with hospital and posthospital outcomes related to delirium was evaluated.

RESULTS: Representative results included adjusted mean length of stay, which increased across levels of short-form severity from 6.5 days (95% CI, 6.2 to 6.9 days) to 12.7 days (CI, 11.2 to 14.3 days) (P for trend and < 0.001) and across levels of long-form severity from 5.6 days (CI, 5.1 to 6.1 days) to 11.9 days (CI, 10.8 to 12.9 days) (P for trend andlt; 0.001). Representative results for the composite outcome of adjusted relative risk of death or nursing home residence at 90 days increased progressively across levels of short-form severity from 1.0 (referent) to 2.5 (CI, 1.9 to 3.3) (P for trend andlt; 0.001) and across levels of long-form severity from 1.0 (referent) to 2.5 (CI, 1.6 to 3.7) (P for trend and < 0.001).

LIMITATION: Data on clinical outcomes were measured in an older data set limited to patients aged 70 years or older.

CONCLUSION: The CAM-S provides a new delirium severity measure with strong psychometric properties and strong associations with important clinical outcomes.

PRIMARY FUNDING SOURCE: National Institute on Aging.

Preventive behaviors and knowledge of tick-borne illnesses: results of a survey from an endemic area

Mon, 08/24/2015 - 2:24pm

CONTEXT: Lyme disease (LD) is the most commonly reported vector-borne illness in the United States. With physically and economically burdensome effects, it is a concern of public health officials.

OBJECTIVES: To assess knowledge and preventive behaviors of individuals in the endemic area of Martha's Vineyard, Massachusetts, to better understand how sociodemographic data and knowledge correlate with preventive behaviors, and to update previous island studies.

DESIGN: A 30-item paper-based anonymous survey in either English or Portuguese based on language preference.

SETTING: The island of Martha's Vineyard and the ferry between island and mainland.

PARTICIPANTS: A total of 946 participants were recruited at 1 of 4 island locations. The majority of participants were traveling by ferry to and from Martha's Vineyard. To reach 2 populations potentially at high risk, that is, youths and outdoor workers, 3 additional venues included the island high school, an English-as-a-Second-Language class, and a local Brazilian church.

OUTCOME MEASURES: Four specific preventive behaviors as well as an overall composite prevention score.

RESULTS: Participants' knowledge of tick-borne illnesses was poor, and the frequency of practicing preventive behaviors was low; the most commonly reported behavior was checking one's skin for ticks (45%). Approximately one-third of respondents (37%) stated that they did not know the late symptoms of untreated LD, nor did they know early LD treatment options (49%). The 2 high-risk groups reported little participation in preventive measures. In multivariate analyses, only 4 characteristics-older age, confidence in telling deer tick from wood tick, seeing tick-borne illness as a serious threat, and certainty in ability to identify LD symptoms-attained significance associated with preventive behavior as an overall composite score.

CONCLUSIONS: Public health interventions focusing on accurately communicating risk, improving knowledge both of LD symptoms and of ticks that carry the disease, as well as teaching preventive behaviors may help reduce tick-borne illness rates.

Stratifying the risks of oral anticoagulation in patients with liver disease

Mon, 08/24/2015 - 2:24pm

BACKGROUND: Chronic liver disease presents a relative contraindication to warfarin therapy, but some patients with liver disease nevertheless require long-term anticoagulation. The goal is to identify which patients with liver disease might safely receive warfarin.

METHODS AND RESULTS: Among 102 134 patients who received warfarin from the Veterans Affairs from 2007 to 2008, International Classification of Diseases-Ninth Revision codes identified 1763 patients with chronic liver disease. Specific diagnoses and laboratory values (albumin, aspartate aminotransferase, alanine aminotransferase, creatinine, and cholesterol) were examined to identify risk of adverse outcomes, while controlling for available bleeding risk factors. Outcomes included percent time in therapeutic range, a measure of anticoagulation control, and major hemorrhagic events, by International Classification of Diseases-Ninth Revision codes. Patients with liver disease had lower mean time in therapeutic range (53.5%) when compared with patients without (61.7%; P < 0.001) and more hemorrhages (hazard ratio, 2.02; P < 0.001). Among patients with liver disease, serum albumin and creatinine levels were the strongest predictors of both outcomes. We created a 4-point score system: patients received 1 point each for albumin (2.5-3.49 g/dL) or creatinine (1.01-1.99 mg/dL), and 2 points each for albumin ( < 2.5 g/dL) or creatinine ( > /=2 mg/dL). This score predicted both anticoagulation control and hemorrhage. When compared with patients without liver disease, those with a score of zero had modestly lower time in therapeutic range (56.7%) and no increase in hemorrhages (hazard ratio, 1.16; P=0.59), whereas those with the worst score (4) had poor control (29.4%) and high hazard of hemorrhage (hazard ratio, 8.53; P < 0.001).

CONCLUSIONS: Patients with liver disease receiving warfarin have poorer anticoagulation control and more hemorrhages. A simple 4-point scoring system using albumin and creatinine identifies those at risk for poor outcomes.

Cigarette smoking and gestational diabetes mellitus in Hispanic woman

Mon, 08/24/2015 - 2:24pm

AIMS: Hispanic women are at increased risk of gestational diabetes mellitus (GDM) as compared to non-Hispanic white women. While smoking has been associated with increased risk of type 2 diabetes, studies of smoking and GDM are sparse and conflicting. Therefore, we evaluated the relationship between cigarette smoking and GDM in Hispanic women.

METHODS: We conducted a pooled analysis of two Hispanic datasets based in Massachusetts: the UMass Medical Health Care dataset and the Proyecto Buena Salud dataset. A total of 3029 Hispanic prenatal care patients with singleton gestations were included. Cigarette smoking prior to and during pregnancy was collected via self-report. Diagnosis of GDM was abstracted from medical records and confirmed by study obstetricians.

RESULTS: One-fifth of participants (20.4%) reported smoking prior to pregnancy, and 11.0% reported smoking in pregnancy. A total of 143 women (4.7%) were diagnosed with GDM. We did not observe an association between pre-pregnancy cigarette smoking and odds of GDM (multivariable OR=0.77, 95% CI 0.47, 1.25). In contrast, smoking during pregnancy was associated with a 54% reduction in odds of GDM (OR=0.46, 95% CI 0.22, 0.95). However, this association was no longer statistically significant after adjustment for age, parity, and study site (OR=0.47, 95% CI 0.23, 1.00).

CONCLUSIONS: In this population of Hispanic pregnant women, we did not observe statistically significant associations between pre-pregnancy smoking and odds of GDM. A reduction in odds of GDM among those who smoked during pregnancy was no longer apparent after adjustment for important diabetes risk factors.

Linkage of a de-identified United States rheumatoid arthritis registry with administrative data to facilitate comparative effectiveness research

Mon, 08/24/2015 - 2:24pm

OBJECTIVE: Linkages between registries and administrative data may provide a valuable resource for comparative effectiveness research. However, personal identifiers that uniquely identify individuals are not always available. Here we describe methods to link a de-identified arthritis registry and US Medicare data. The linked data set was also used to evaluate the generalizability of the registry to the US Medicare population.

METHODS: Rheumatoid arthritis (RA) patients participating in the Consortium of Rheumatology Researchers of North America (CORRONA) registry were linked to Medicare data restricted to rheumatology claims or claims for RA. Deterministic linkage was performed using age, sex, provider identification number, and geographic location of the CORRONA site. We then searched for visit dates in Medicare matching visit dates in CORRONA, requiring > /=1 exact matching date. Linkage accuracy was quantified as a positive predictive value in a subcohort (n = 1,581) with more precise identifiers.

RESULTS: CORRONA participants with self-reported Medicare (n = 11,001) were initially matched to 30,943 Medicare beneficiaries treated by CORRONA physicians. A total of 8,431 CORRONA participants matched on > /=1 visit; 5,317 matched uniquely on all visits. The number of patients who linked and linkage accuracy (from the subcohort) were high for patients with > 2 visits (n = 3,458, 98% accuracy), exactly 2 visits (n = 822, 96% accuracy), and 1 visit (n = 1,037, 79% accuracy) that matched exactly on calendar date. Demographics and comorbidity profiles of registry participants were similar to nonparticipants, except participants were more likely to take disease-modifying antirheumatic drugs and biologic agents.

CONCLUSION: Linkage between a national, de-identified outpatient arthritis registry and Medicare data on multiple nonunique identifiers appears feasible and valid.

A group-randomized trial of shared decision making for non-steroidal anti-inflammatory drug risk awareness: primary results and lessons learned

Mon, 08/24/2015 - 2:24pm

RATIONALE, AIMS AND OBJECTIVES: Frequent use and serious adverse effects related to non-steroidal anti-inflammatory drugs (NSAIDs) underscore the need to raise patient awareness about potential risks. Partial success of patient- or provider-based interventions has recently led to interest in combined approaches focusing on both patient and physician. This research tested a shared decision-making intervention for increasing patient-reported awareness of NSAID risk.

METHODS: A group randomized trial was performed in Alabama from 2005 to 2007. Intervention group doctor practices received continuing medical education (CME) about NSAIDs and patient activation tools promoting risk assessment and communication during visits. Comparison group doctor practices received only CME. Cross-sectional data were collected before and after the intervention. Generalized linear latent and mixed models with logistic link tested relationships among the intervention, study phase, intervention by study phase interaction and patient-reported awareness of risks with either prescription or over-the-counter (OTC) NSAIDs.

RESULTS: Three hundred and forty-seven patients at baseline and 355 patients at follow-up participated in this study. The intervention [adjusted odds ratio (AOR)=0.74, P=0.248], follow-up study phase (AOR=1.31, P=0.300) and intervention by study phase interaction (AOR=0.98, P=0.942) were not significantly associated with patient-reported awareness of any prescription NSAID risk. Follow-up study phase was associated with increased odds of reporting any OTC NSAID risk awareness (AOR=2.99, P < 0.001), but the patient activation intervention and intervention by study phase interaction were not significantly associated with patient-reported awareness of any OTC NSAID risk (AOR=0.98, P=0.929; AOR=0.87, P=0.693, respectively).

CONCLUSIONS: Our point-of-care intervention encouraging shared decision making did not increase NSAID risk awareness.

Differential expression of APE1 and APE2 in germinal centers promotes error-prone repair and A:T mutations during somatic hypermutation

Mon, 08/24/2015 - 2:24pm

Somatic hypermutation (SHM) of antibody variable region genes is initiated in germinal center B cells during an immune response by activation-induced cytidine deaminase (AID), which converts cytosines to uracils. During accurate repair in nonmutating cells, uracil is excised by uracil DNA glycosylase (UNG), leaving abasic sites that are incised by AP endonuclease (APE) to create single-strand breaks, and the correct nucleotide is reinserted by DNA polymerase beta. During SHM, for unknown reasons, repair is error prone. There are two APE homologs in mammals and, surprisingly, APE1, in contrast to its high expression in both resting and in vitro-activated splenic B cells, is expressed at very low levels in mouse germinal center B cells where SHM occurs, and APE1 haploinsufficiency has very little effect on SHM. In contrast, the less efficient homolog, APE2, is highly expressed and contributes not only to the frequency of mutations, but also to the generation of mutations at A:T base pair (bp), insertions, and deletions. In the absence of both UNG and APE2, mutations at A:T bp are dramatically reduced. Single-strand breaks generated by APE2 could provide entry points for exonuclease recruited by the mismatch repair proteins Msh2-Msh6, and the known association of APE2 with proliferating cell nuclear antigen could recruit translesion polymerases to create mutations at AID-induced lesions and also at A:T bp. Our data provide new insight into error-prone repair of AID-induced lesions, which we propose is facilitated by down-regulation of APE1 and up-regulation of APE2 expression in germinal center B cells.

Tweeting it off: characteristics of adults who tweet about a weight loss attempt

Mon, 08/24/2015 - 2:24pm

OBJECTIVE: The purpose of this study was to describe adults who use Twitter during a weight loss attempt and to compare the positive and negative social influences they experience from their offline friends, online friends, and family members.

MATERIALS AND METHODS: Participants (N=100, 80% female, mean age=37.65, SD=8.42) were recruited from Twitter. They completed a brief survey about their experiences discussing their weight loss attempt with their online and offline friends and provided responses to open-ended questions on the benefits and drawbacks of discussing weight on Twitter, Facebook, and weight-specific social networks.

RESULTS: Participants rated their connections on Twitter and weight loss-specific social networks to be significantly greater sources of positive social influence for their weight loss (F(3)=3.47; p < 0.001) and significantly lesser sources of negative social influence (F(3)=40.39 and F(3)=33.68 (both p < 0.001)) than their offline friends, family, and Facebook friends. Greater positive social influence from Twitter and Facebook friends was associated with greater weight loss in participants' most recent weight loss attempt (r=0.30, r=0.32; p < 0.01). The most commonly reported benefits of tweeting about weight loss include social support, information, and accountability. The most common drawbacks reported are that interactions were too brief and lacked personal connection.

DISCUSSION: People who discuss their weight loss on Twitter report more social support and less negativity from their Twitter friends than their Facebook friends and in-person relationships.

CONCLUSIONS: Online social networks should be explored as a tool for connecting patients who lack weight loss social support from their in-person relationships.

Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to

An integrated approach in a case of facioscapulohumeral dystrophy

Mon, 08/24/2015 - 9:45am

BACKGROUND: Muscle fatigue, weakness and atrophy are basilar clinical features that accompany facioscapulohumeral dystrophy (FSHD) the third most common muscular dystrophy.No therapy is available for FSHD.

CASE PRESENTATION: We describe the effects of 6mo exercise therapy and nutritional supplementation in a 43-year-old woman severely affected by FSHD.

CONCLUSION: A mixed exercise program combined with nutritional supplementation can be safely used with beneficial effects in selected patients with FSHD.

PLAAC: a web and command-line application to identify proteins with prion-like amino acid composition

Mon, 08/24/2015 - 9:45am

Prions are self-templating protein aggregates that stably perpetuate distinct biological states and are of keen interest to researchers in both evolutionary and biomedical science. The best understood prions are from yeast and have a prion-forming domain with strongly biased amino acid composition, most notably enriched for Q or N. PLAAC is a web application that scans protein sequences for domains with P: rion- L: ike A: mino A: cid C: omposition. Users can upload sequence files, or paste sequences directly into a textbox. PLAAC ranks the input sequences by several summary scores and allows scores along sequences to be visualized. Text output files can be downloaded for further analyses, and visualizations saved in PDF and PNG formats.

AVAILABILITY AND IMPLEMENTATION: The Ruby-based web framework and the command-line software (implemented in Java, with visualization routines in R) are available at under the MIT license. All software can be run under OS X, Windows and Unix.

Gene therapy for the nervous system: challenges and new strategies

Mon, 08/24/2015 - 9:45am

Current clinical treatments for central nervous system (CNS) diseases, such as Parkinson's disease and glioblastoma do not halt disease progression and have significant treatment morbidities. Gene therapy has the potential to "permanently" correct disease by bringing in a normal gene to correct a mutant gene deficiency, knocking down mRNA of mutant alleles, and inducing cell-death in cancer cells using transgenes encoding apoptosis-inducing proteins. Promising results in clinical trials of eye disease (Leber's congenital aumorosis) and Parkinson's disease have shown that gene-based neurotherapeutics have great potential. The recent development of genome editing technology, such as zinc finger nucleases, TALENS, and CRISPR, has made the ultimate goal of gene correction a step closer. This review summarizes the challenges faced by gene-based neurotherapeutics and the current and recent strategies designed to overcome these barriers. We have chosen the following challenges to focus on in this review: (1) delivery vehicles (both virus and nonviral), (2) use of promoters for vector-mediated gene expression in CNS, and (3) delivery across the blood-brain barrier. The final section (4) focuses on promising pre-clinical/clinical studies of neurotherapeutics.

Biomarkers for disease progression and AAV therapeutic efficacy in feline Sandhoff disease

Mon, 08/24/2015 - 9:45am

The GM2 gangliosidoses, Tay-Sachs disease (TSD) and Sandhoff disease (SD), are progressive neurodegenerative disorders that are caused by a mutation in the enzyme beta-N-acetylhexosaminidase (Hex). Due to the recent emergence of novel experimental treatments, biomarker development has become particularly relevant in GM2 gangliosidosis as an objective means to measure therapeutic efficacy. Here we describe blood, cerebrospinal fluid (CSF), magnetic resonance imaging (MRI), and electrodiagnostic methods for evaluating disease progression in the feline SD model and application of these approaches to assess AAV-mediated gene therapy. SD cats were treated by intracranial injections of the thalami combined with either the deep cerebellar nuclei or a single lateral ventricle using AAVrh8 vectors encoding feline Hex. Significantly altered in untreated SD cats, blood and CSF based biomarkers were largely normalized after AAV gene therapy. Also reduced after treatment were expansion of the lysosomal compartment in peripheral blood mononuclear cells and elevated activity of secondary lysosomal enzymes. MRI changes characteristic of the gangliosidoses were documented in SD cats and normalized after AAV gene therapy. The minimally invasive biomarkers reported herein should be useful to assess disease progression of untreated SD patients and those in future clinical trials.

Novel mutations support a role for Profilin 1 in the pathogenesis of ALS

Mon, 08/24/2015 - 9:45am

Mutations in the gene encoding profilin 1 (PFN1) have recently been shown to cause amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disorder. We sequenced the PFN1 gene in a cohort of ALS patients (n = 485) and detected 2 novel variants (A20T and Q139L), as well as 4 cases with the previously identified E117G rare variant ( approximately 1.2%). A case-control meta-analysis of all published E117G ALS+/- frontotemporal dementia cases including those identified in this report was significant p = 0.001, odds ratio = 3.26 (95% confidence interval, 1.6-6.7), demonstrating this variant to be a susceptibility allele. Postmortem tissue from available patients displayed classic TAR DNA-binding protein 43 pathology. In both transient transfections and in fibroblasts from a patient with the A20T change, we showed that this novel PFN1 mutation causes protein aggregation and the formation of insoluble high molecular weight species which is a hallmark of ALS pathology. Our findings show that PFN1 is a rare cause of ALS and adds further weight to the underlying genetic heterogeneity of this disease.

The distinct genetic pattern of ALS in Turkey and novel mutations

Mon, 08/24/2015 - 9:45am

The frequency of amyotrophic lateral sclerosis (ALS) mutations has been extensively investigated in several populations; however, a systematic analysis in Turkish cases has not been reported so far. In this study, we screened 477 ALS patients for mutations, including 116 familial ALS patients from 82 families and 361 sporadic ALS (sALS) cases. Patients were genotyped for C9orf72 (18.3%), SOD1 (12.2%), FUS (5%), TARDBP (3.7%), and UBQLN2 (2.4%) gene mutations, which together account for approximately 40% of familial ALS in Turkey. No SOD1 mutations were detected in sALS patients; however, C9orf72 (3.1%) and UBQLN2 (0.6%) explained 3.7% of sALS in the population. Exome sequencing revealed mutations in OPTN, SPG11, DJ1, PLEKHG5, SYNE1, TRPM7, and SQSTM1 genes, many of them novel. The spectrum of mutations reflect both the distinct genetic background and the heterogeneous nature of the Turkish ALS population.

AAV-mediated gene delivery in a feline model of Sandhoff disease corrects lysosomal storage in the central nervous system

Mon, 08/24/2015 - 9:45am

Sandhoff disease (SD) is an autosomal recessive neurodegenerative disease caused by a mutation in the gene for the beta-subunit of beta-N-acetylhexosaminidase (Hex), resulting in the inability to catabolize ganglioside GM2 within the lysosomes. SD presents with an accumulation of GM2 and its asialo derivative GA2, primarily in the central nervous system. Myelin-enriched glycolipids, cerebrosides and sulfatides, are also decreased in SD corresponding with dysmyelination. At present, no treatment exists for SD. Previous studies have shown the therapeutic benefit of adeno-associated virus (AAV) vector-mediated gene therapy in the treatment of SD in murine and feline models. In this study, we treated presymptomatic SD cats with AAVrh8 vectors expressing feline Hex in the thalamus combined with intracerebroventricular (Thal/ICV) injections. Treated animals showed clearly improved neurologic function and quality of life, manifested in part by prevention or attenuation of whole-body tremors characteristic of untreated animals. Hex activity was significantly elevated, whereas storage of GM2 and GA2 was significantly decreased in tissue samples taken from the cortex, cerebellum, thalamus, and cervical spinal cord. Treatment also increased levels of myelin-enriched cerebrosides and sulfatides in the cortex and thalamus. This study demonstrates the therapeutic potential of AAV for feline SD and suggests a similar potential for human SD patients.

Bis(monoacylglycero)phosphate: a secondary storage lipid in the gangliosidoses

Mon, 08/24/2015 - 9:45am

Bis(monoacylglycero)phosphate (BMP) is a negatively charged glycerophospholipid with an unusual sn-1;sn-1' structural configuration. BMP is primarily enriched in endosomal/lysosomal membranes. BMP is thought to play a role in glycosphingolipid degradation and cholesterol transport. Elevated BMP levels have been found in many lysosomal storage diseases (LSDs), suggesting an association with lysosomal storage material. The gangliosidoses are a group of neurodegenerative LSDs involving the accumulation of either GM1 or GM2 gangliosides resulting from inherited deficiencies in beta-galactosidase or beta-hexosaminidase, respectively. Little information is available on BMP levels in gangliosidosis brain tissue. Our results showed that the content of BMP in brain was significantly greater in humans and in animals (mice, cats, American black bears) with either GM1 or GM2 ganglioside storage diseases, than in brains of normal subjects. The storage of BMP and ganglioside GM2 in brain were reduced similarly following adeno-associated viral-mediated gene therapy in Sandhoff disease mice. We also found that C22:6, C18:0, and C18:1 were the predominant BMP fatty acid species in gangliosidosis brains. The results show that BMP accumulates as a secondary storage material in the brain of a broad range of mammals with gangliosidoses.

Mucopolysaccharidosis-like phenotype in feline Sandhoff disease and partial correction after AAV gene therapy

Mon, 08/24/2015 - 9:45am

Sandhoff disease (SD) is a fatal neurodegenerative disease caused by a mutation in the enzyme beta-N-acetylhexosaminidase. Children with infantile onset SD develop seizures, loss of motor tone and swallowing problems, eventually reaching a vegetative state with death typically by 4years of age. Other symptoms include vertebral gibbus and cardiac abnormalities strikingly similar to those of the mucopolysaccharidoses. Isolated fibroblasts from SD patients have impaired catabolism of glycosaminoglycans (GAGs). To evaluate mucopolysaccharidosis-like features of the feline SD model, we utilized radiography, MRI, echocardiography, histopathology and GAG quantification of both central nervous system and peripheral tissues/fluids. The feline SD model exhibits cardiac valvular and structural abnormalities, skeletal changes and spinal cord compression that are consistent with accumulation of GAGs, but are much less prominent than the severe neurologic disease that defines the humane endpoint (4.5+/-0.5months). Sixteen weeks after intracranial AAV gene therapy, GAG storage was cleared in the SD cat cerebral cortex and liver, but not in the heart, lung, skeletal muscle, kidney, spleen, pancreas, small intestine, skin, or urine. GAG storage worsens with time and therefore may become a significant source of pathology in humans whose lives are substantially lengthened by gene therapy or other novel treatments for the primary, neurologic disease.

Survival benefit and phenotypic improvement by hamartin gene therapy in a tuberous sclerosis mouse brain model

Mon, 08/24/2015 - 9:45am

We examined the potential benefit of gene therapy in a mouse model of tuberous sclerosis complex (TSC) in which there is embryonic loss of Tsc1 (hamartin) in brain neurons. An adeno-associated virus (AAV) vector (serotype rh8) expressing a tagged form of hamartin was injected into the cerebral ventricles of newborn pups with the genotype Tsc1cc (homozygous for a conditional floxed Tsc1 allele) SynI-cre+, in which Tsc1 is lost selectively in neurons starting at embryonic day 12. Vector-treated Tsc1ccSynIcre+ mice showed a marked improvement in survival from a mean of 22days in non-injected mice to 52days in AAV hamartin vector-injected mice, with improved weight gain and motor behavior in the latter. Pathologic studies showed normalization of neuron size and a decrease in markers of mTOR activation in treated as compared to untreated mutant littermates. Hence, we show that gene replacement in the brain is an effective therapeutic approach in this mouse model of TSC1. Our strategy for gene therapy has the advantages that therapy can be achieved from a single application, as compared to repeated treatment with drugs, and that AAV vectors have been found to have minimal to no toxicity in clinical trials for other neurologic conditions. Although there are many additional issues to be addressed, our studies support gene therapy as a useful approach in TSC patients.