Huntington's Disease-Related Mortality Patterns: A Two-Decade Analysis of Mortality Trends in the United States, from 1999-2019.

Background: Huntington's disease (HD) is an autosomal dominant, progressive neurodegenerative disorder debilitating mainly in adults. Objective: This study aimed to assess the trends in HD-related mortality regarding various demographic factors. Methods: Death certificates from the CDC WONDER were studied from 1999 to 2019, for HD-related mortality in adults aged 25 + years. Age-adjusted Mortality Rate (AAMR) per 100,000 persons and Annual Percentage Change (APC) were calculated and stratified by year, age groups, gender, race/ethnicity, state, census region, urbanization, and place of death. Results: Between 1999 to 2019, 22,595 deaths occurred in adults due to HD. The AAMR increased from 0.43 to 0.54 during this period (APC = 0.50; 95% CI: 0.18 to 0.84). Old adults (65-85 + years) had the highest overall AAMR, followed by middle-aged adults (45-64 years) and young adults (25-44 years) (AAMR old: 1.01 vs. AAMR middle-age: 0.68 vs. AAMR young: 0.16). Men had slightly greater overall AAMRs than women (AAMR men: 0.54 vs. AAMR women: 0.48). When stratified by race, non-Hispanic (NH) Whites had significantly higher mortality rates than NH African Americans (AAMR NH White: 0.61 vs. NH African American: 0.35), while the AAMR were lowest in Hispanic/Latino (0.28). The AAMRs also showed variation by region (overall AAMR: Midwest: 0.63, Northeast: 0.47, West: 0.48, South: 0.46), and non-metropolitan areas had higher HD-related AAMR (0.66) than metropolitan areas (0.47). Conclusions: HD-related mortality in US adults has increased since 1999. Reflecting on the variations in trends observed, new strategies are required to optimize the quality of care in long-term care facilities.

Outcomes of Percutaneous Endoscopic Gastrostomy in Huntington's Disease at a Tertiary Center.

BACKGROUND: Clinically assisted nutrition and hydration via percutaneous endoscopic gastrostomy (PEG) is a therapeutic option to ameliorate the difficulties associated with enhanced catabolism, weight loss, and dysphagia in Huntington's disease (HD). OBJECTIVES: The objective is to provide insights into demographics, staging (Shoulson-Fahn), complications, weight trajectories, and survival rates in people with HD (pwHD) who underwent PEG. METHODS: This retrospective study included 705 consecutive pwHD who attended our HD clinic between July 2006 and March 2024, of whom 52 underwent PEG. A control group (n = 52), comprising pwHD without PEG, were closely matched for sex, stage, age, CAG length, and disease burden score at PEG. The study was registered as a service evaluation at the National Hospital for Neurology and Neurosurgery. RESULTS: PEG prevalence was 15.0% (n = 52/347) among manifest pwHD: 4.8% (n = 3/62) for Stage 3; 33.3% (n = 16/48) for stage 4; and 44.1% (n = 30/68) for stage 5. Commonest indications were dysphagia, weight loss, and inadequate oral intake. Complications included chest infection, tube dislodgement, and peristomal and skin infections. Modeling of weight trajectories after PEG found no difference between PEG and non-PEG groups. Mortality rate was 34.6% (n = 18/52) in the PEG and 36.5% (n = 19/52) in the non-PEG groups (P = 0.84). Treatment duration (until study endpoint or death) was 3.48 years (interquartile range = 1.71-6.02; range = 0.23-18.8), with 65.4% (n = 34/52) alive at the study endpoint. CONCLUSION: PEG in pwHD at-risk for weight loss may help slow weight loss. Prospective studies are required to strengthen PEG decision-making in pwHD. PEG survival was much longer than other dementias, highlighting the need to consider PEG independently in pwHD.

Longer CAG repeat length is associated with shorter survival after disease onset in Huntington disease.

It is well known that the length of the CAG trinucleotide expansion of the huntingtin gene is associated with many aspects of Huntington disease progression. These include age of clinical onset and rate of initial progression of disease severity. The relationship between CAG length and survival in Huntington disease is less studied. To address this, we obtained the complete Registry HD database from the European Huntington Disease Network and reanalyzed the time from reported age of disease onset until death. We conducted semiparametric proportional hazards modeling of 8,422 participants who had experienced onset of clinical Huntington disease, either retrospectively or prospectively. Of these, 826 had a recorded age of death. To avoid biased model estimates, retrospective onset ages were represented by left truncation at study entry. After controlling for onset age, which tends to be younger in those with longer CAG repeat lengths, we found that CAG length had a substantial and highly significant influence upon survival time after disease onset. For a fixed age of onset, longer CAG expansions were predictive of shorter survival. This is consistent with other known relationships between CAG length and disease severity. We also show that older onset age predicts shorter lifespan after controlling for CAG length and that the influence of CAG on survival length is substantially greater in women. We demonstrate that apparent contradictions between these and previous analyses of the same data are primarily due to the question of whether to control for clinical onset age in the analysis of time until death.

Netboost: Boosting-Supported Network Analysis Improves High-Dimensional Omics Prediction in Acute Myeloid Leukemia and Huntington's Disease.

State-of-the art selection methods fail to identify weak but cumulative effects of features found in many high-dimensional omics datasets. Nevertheless, these features play an important role in certain diseases. We present Netboost, a three-step dimension reduction technique. First, a boosting-based filter is combined with the topological overlap measure to identify the essential edges of the network. Second, sparse hierarchical clustering is applied on the selected edges to identify modules and finally module information is aggregated by the first principal components. We demonstrate the application of the newly developed Netboost in combination with CoxBoost for survival prediction of DNA methylation and gene expression data from 180 acute myeloid leukemia (AML) patients and show, based on cross-validated prediction error curve estimates, its prediction superiority over variable selection on the full dataset as well as over an alternative clustering approach. The identified signature related to chromatin modifying enzymes was replicated in an independent dataset, the phase II AMLSG 12-09 study. In a second application we combine Netboost with Random Forest classification and improve the disease classification error in RNA-sequencing data of Huntington's disease mice. Netboost is a freely available Bioconductor R package for dimension reduction and hypothesis generation in high-dimensional omics applications.

Bim contributes to the progression of Huntington's disease-associated phenotypes.

Huntington's disease (HD) is a neurodegenerative disorder caused by an expanded polyglutamine tract in the huntingtin (HTT) protein. Mutant HTT (mHTT) toxicity is caused by its aggregation/oligomerization. The striatum is the most vulnerable region, although all brain regions undergo neuronal degeneration in the disease. Here we show that the levels of Bim, a BH3-only protein, are significantly increased in HD human post-mortem and HD mouse striata, correlating with neuronal death. Bim reduction ameliorates mHTT neurotoxicity in HD cells. In the HD mouse model, heterozygous Bim knockout significantly mitigates mHTT accumulation and neuronal death, ameliorating disease-associated phenotypes and lifespan. Therefore, Bim could contribute to the progression of HD.

Biological and clinical manifestations of juvenile Huntington's disease: a retrospective analysis.

BACKGROUND: Huntington's disease is a rare, neurodegenerative disease caused by an expanded CAG repeat mutation in the huntingtin gene. Compared with adult-onset Huntington's disease, juvenile Huntington's disease (onset ≤20 years) is even rarer and has not been studied extensively. We aimed to further characterise juvenile Huntington's disease by examining the effect of CAG repeat size on disease presentation, progression, and survival. METHODS: We did a retrospective analysis of patients with juvenile Huntington's disease aged 20 years or younger, according to the length of their CAG repeat and who had disabling psychiatric symptoms (with motor symptoms) or motor symptoms alone, and of patients with adult-onset Huntington's disease manifesting aged 30-60 years with 40 or more CAG repeats, from the REGISTRY and ENROLL-HD platforms and from two institutional databases (Lega Italiana Ricerca Huntington Foundation and the Instituto Neurociencias de Buenos Aires and the Sanatorio de la Trinidad Mitre). Patients with psychiatric but no motor symptoms were excluded. We compared symptoms at onset and longitudinally in patients with juvenile Huntington's disease with highly expanded (HE subgroup) or low expansion (LE subgroup) mutations, grouped by hierarchical clustering analysis. We also compared disease progression (longitudinal change in Unified Huntington's Disease Rating Scale-Total Motor Score) and survival of patients with juvenile and adult-onset Huntington's disease. FINDINGS: We extracted medical records from 580 patients entered into the studies or databases between June 23, 2004, and March 31, 2018, of whom 36 patients met our definition of juvenile Huntington's disease and 197 for adult-onset Huntington's disease. According to caregiver reports, gait disturbance was more often a first presenting symptom in the HE subgroup (eight [80%] of 10 patients) than in the LE subgroup (seven [27%] of 26 patients; p=0·0071), whereas loss of hand dexterity was more common in the LE subgroup (11 [42%] of 26 patients) than in the HE subgroup (0 [0%] of 10 patients; p=0·0160). Compared with the LE subgroup, development delay (0 [0%] in the LE subgroup vs nine [90%] in the HE subgroup; p<0·0001), severe gait impairment (nine [35%] in the LE subgroup vs nine [90%] in the HE subgroup; p=0·0072), and seizures (three [11%] in the LE subgroup vs eight [80%] in the HE subgroup; p<0·0001) prevailed over time in the HE subgroup. Disease progression was more rapid in juvenile Huntington's disease (n=14) than in adult-onset Huntington's disease (n=52; generalised estimating equation model, p=0·0003). Of 121 deceased patients, median survival was shorter in the juvenile Huntington's disease (n=17) cohort than in adult-onset Huntington's disease (n=104) cohort (hazard ratio 2·18 [95% CI 1·08-4·40]; p=0·002). INTERPRETATION: Patients with HE juvenile Huntington's disease differ clinically from patients with LE juvenile Huntington's disease or adult-onset Huntington's disease, suggesting reclassification of this particularly aggressive form of Huntington's disease might be required. FUNDING: Lega Italiana Ricerca Huntington Foundation and IRCCS Ospedale Casa Sollievo della Sofferenza.

A Huntingtin Knockin Pig Model Recapitulates Features of Selective Neurodegeneration in Huntington's Disease.

Huntington's disease (HD) is characterized by preferential loss of the medium spiny neurons in the striatum. Using CRISPR/Cas9 and somatic nuclear transfer technology, we established a knockin (KI) pig model of HD that endogenously expresses full-length mutant huntingtin (HTT). By breeding this HD pig model, we have successfully obtained F1 and F2 generation KI pigs. Characterization of founder and F1 KI pigs shows consistent movement, behavioral abnormalities, and early death, which are germline transmittable. More importantly, brains of HD KI pig display striking and selective degeneration of striatal medium spiny neurons. Thus, using a large animal model of HD, we demonstrate for the first time that overt and selective neurodegeneration seen in HD patients can be recapitulated by endogenously expressed mutant proteins in large mammals, a finding that also underscores the importance of using large mammals to investigate the pathogenesis of neurodegenerative diseases and their therapeutics.

Age at Death and Causes of Death in Patients with Huntington Disease in Norway in 1986-2015.

BACKGROUND: The literature offers discrepant findings regarding age at death in individuals with Huntington disease (HD). OBJECTIVE: To study the age at death and causes of death in males and females with a diagnosis of HD in Norway. METHODS: Registry study of deaths in 1986-2015 using data from two national registries: the Norwegian Cause of Death Registry (NCDR) and the registry of the Centre for Rare Disorders (CRD), Oslo University Hospital. RESULTS: Mean age at death for individuals with HD was found to be 63.9 years (NCDR) and 61.7 years (CRD), compared to a mean of 76.9 years in the general population (NCDR). There were no significant gender differences for age at death in individuals with HD. The significant increase in age at death within the general population from 1986 to 2015 was not observed in individuals with HD. In 73.5% of individuals with HD, the underlying cause of death was HD, followed by cardiovascular diseases, cancer and respiratory diseases. The most common immediate cause of death was respiratory diseases (44.2%). Suicide was a more common cause of death in the population with HD (2.3%) compared to the general population (1.3%). CONCLUSION: The age at death of individuals with HD was stable over a period of 30 years and 13.3 years lower than in the general population. Longer life expectancy for females from the general population was not found in females with HD. Suicide was more common among individuals with HD compared to the general population.

Activation of NPY-Y2 receptors ameliorates disease pathology in the R6/2 mouse and PC12 cell models of Huntington's disease.

Huntington's disease (HD) is a monogenic inherited polyglutamine-mediated neurodegenerative disorder for which effective therapies are currently unavailable. Neuropeptide Y (NPY) has been implicated as a potential therapeutic target in several neurodegenerative diseases, including HD. However, its mechanisms of action in the context of HD pathology remain unknown. Here, we investigated the beneficial effects of Y2 receptor (Y2R) activation with NPY or Y2R selective agonist NPY13-36 in the R6/2 mouse and PC12 cell models of HD. Also, we explored the effects of selective pharmacological blockage of Y2R using selective non-peptide small molecule Y2R antagonist SF31 in vivo and in vitro. Our results showed that activation of Y2R with intranasal NPY or NPY13-36 led to an improved motor function in R6/2 mice as revealed by rotarod performance, vertical pole test, and hindlimb clasping behaviour. Also, intranasal NPY or NPY13-36 led to a decrease in aggregated mHtt and mediated increase in dopamine and cAMP-regulated phosphoprotein, 32kDa (DARPP-32), brain-derived neurotrophic factor (BDNF), and activated extracellular signal-regulated protein kinases (pERK1/2) levels in R6/2 mice. Intranasal NPY or NPY13-36 had no effect on body weight but showed positive effects on survival in R6/2 mice. Furthermore, intranasal NPY or NPY13-36 attenuated induction of proinflammatory cytokine and inflammatory mediators in R6/2 mice. In contrast, antagonizing by using SF31 exacerbates phenotypic severity in R6/2 mice and treatment effects with either intranasal NPY or NPY13-36 were significantly blocked.In vitro, using inducible PC12/HttQ103-EGFP cells, treatment with NPY or NPY13-36 protected against mHtt-mediated neuromorphological defects (neurite length and soma area) and neurotoxicity but had no effect on mHtt inclusion body formation. Conversely, co-treatment with SF31 significantly inhibited these effects. Together, our findings extend previous evidence of the beneficial effects of NPY in R6/2 mice, and more importantly, suggest that targeted activation of Y2R receptor might be a promising disease-modifying target for HD and other neurodegenerative diseases.

A new measure for end of life planning, preparation, and preferences in Huntington disease: HDQLIFE end of life planning.

BACKGROUND: Huntington disease is a fatal inherited neurodegenerative disease. Because the end result of Huntington disease is death due to Huntington disease-related causes, there is a need for better understanding and caring for individuals at their end of life. AIM: The purpose of this study was to develop a new measure to evaluate end of life planning. DESIGN: We conducted qualitative focus groups, solicited expert input, and completed a literature review to develop a 16-item measure to evaluate important aspects of end of life planning for Huntington disease. Item response theory and differential item functioning analyses were utilized to examine the psychometric properties of items; exploratory factor analysis was used to establish meaningful subscales. PARTICIPANTS: Participants included 508 individuals with pre-manifest or manifest Huntington disease. RESULTS: Item response theory supported the retention of all 16 items on the huntington disease quality of life ("HDQLIFE") end of life planning measure. Exploratory factor analysis supported a four-factor structure: legal planning, financial planning, preferences for hospice care, and preferences for conditions (locations, surroundings, etc.) at the time of death. Although a handful of items exhibited some evidence of differential item functioning, these items were retained due to their relevant clinical content. The final 16-item scale includes an overall total score and four subscale scores that reflect the different end of life planning constructs. CONCLUSIONS: The 16-item HDQLIFE end of life planning measure demonstrates adequate psychometric properties; it may be a useful tool for clinicians to clarify patients' preferences about end of life care.

Epidemiology of Huntington disease in Cyprus: A 20-year retrospective study.

Huntington disease (HD) is most prevalent among populations of western European descent and isolated populations where founder effects may operate. The aim of this study was to examine the epidemiology of HD in Cyprus, an island in southern Europe with extensive western European colonization in the past. All registered HD patients in the Cyprus, since 1994, were included. Detailed pedigrees and clinical information were recorded and maps, showing the geographic distribution of HD, were constructed. Requests for genetic testing were also examined. The project identified 58 clinically manifested cases of HD belonging to 19 families. The 16 families of Cypriot origin were concentrated in a confined geographical cluster in southeast Cyprus. In 2015, prevalence of symptomatic HD was 4.64/100 000 population, while incidence was 0.12/100 000 person-years. Prevalence displayed a marked increase during the past 20 years. Disease characteristics of HD patients were similar to those reported in western European populations. Lastly, the uptake of predictive and/or prenatal testing was limited. HD disease characteristics, incidence and prevalence in Cyprus were comparable to western European populations. Together with the geographical clustering observed, these results support the possibility for a relatively recent founder effect of HD in Cyprus, potentially of western European origin.

Disease-modifying effects of ganglioside GM1 in Huntington's disease models.

Huntington's disease (HD) is a progressive neurodegenerative disorder characterized by motor, cognitive and psychiatric problems. Previous studies indicated that levels of brain gangliosides are lower than normal in HD models and that administration of exogenous ganglioside GM1 corrects motor dysfunction in the YAC128 mouse model of HD In this study, we provide evidence that intraventricular administration of GM1 has profound disease-modifying effects across HD mouse models with different genetic background. GM1 administration results in decreased levels of mutant huntingtin, the protein that causes HD, and in a wide array of beneficial effects that include changes in levels of DARPP32, ferritin, Iba1 and GFAP, modulation of dopamine and serotonin metabolism, and restoration of normal levels of glutamate, GABA, L-Ser and D-Ser. Treatment with GM1 slows down neurodegeneration, white matter atrophy and body weight loss in R6/2 mice. Motor functions are significantly improved in R6/2 mice and restored to normal in Q140 mice, including gait abnormalities that are often resistant to treatments. Psychiatric-like and cognitive dysfunctions are also ameliorated by GM1 administration in Q140 and YAC128 mice. The widespread benefits of GM1 administration, at molecular, cellular and behavioural levels, indicate that this ganglioside has strong therapeutic and disease-modifying potential in HD.

Statistical modeling of Huntington disease onset.

Huntington disease (HD) is caused by a CAG trinucleotide expansion in the huntingtin gene. We now have the power to predict age-at-onset from subject-specific features like motor and neuroimaging measures. In clinical trials, properly modeling onset age is important, because it improves power calculations and directs clinicians to recruit subjects with certain features. The history of modeling onset, from simple linear and logistic regression to advanced survival models, is discussed. We highlight their advantages and disadvantages, emphasizing the methodological challenges when genetic mutation status is unavailable. We also discuss the potential bias and higher variability incurred from the uncertainty associated with subjective definitions for onset. Methods to adjust for the uncertainty in survival models are still in their infancy, but would be beneficial for HD and neurodegenerative diseases with long prodromal periods like Alzheimer's and Parkinson's disease.

Analysis of Participant Withdrawal in Huntington Disease Clinical Trials.

BACKGROUND: Excellent retention in Huntington disease (HD) clinical trials is essential for testing new therapies. The stage of disease, cognitive status, and availability of a care partner may influence retention in HD clinical trials. OBJECTIVE: We sought to analyze reasons for early withdrawal in three HD clinical trials, and evaluated if either baseline characteristics or follow-up assessments were associated with time to withdrawal. METHODS: Analyses of participant withdrawal were performed for three randomized, double-blind, placebo-controlled trials including the CARE-HD (coenzyme Q10 and remacemide in HD, n = 347), DOMINO (pilot study of minocycline in HD, n = 114), and 2CARE (coenzyme Q10 in HD, n = 609) trials. Reasons for withdrawal were obtained by review of textual data in the study databases. Participant demographic and clinical characteristics were analyzed as potential predictors of time to withdrawal using Cox-proportional hazards models. RESULTS: Estimated probabilities of withdrawal at 12 months were 2.9% for CARE-HD, 10.5% for DOMINO, and 5.9% for 2CARE. The top reasons for withdrawal (202 in total), expressed as mean percentage across the three trials, were loss to follow-up (23.2%), death (15.9%), and loss of interest/desire to participate (15.2%). Baseline and time-dependent variables associated with time to withdrawal were mainly motor, behavioral, and functional scores. Age, gender, ethnicity, and educational level were not associated with time to withdrawal in any of the three studies. CONCLUSIONS: The estimated withdrawal probability at 12 months ranged from 2.9% to 10.5% in the three HD trials considered here. A possible strategy to improve retention of participants in future HD clinical trials is to enroll individuals with higher baseline functional and behavioral status.

Remodeling of heterochromatin structure slows neuropathological progression and prolongs survival in an animal model of Huntington's disease.

Huntington's disease (HD) is an autosomal-dominant inherited neurological disorder caused by expanded CAG repeats in exon 1 of the Huntingtin (HTT) gene. Altered histone modifications and epigenetic mechanisms are closely associated with HD suggesting that transcriptional repression may play a pathogenic role. Epigenetic compounds have significant therapeutic effects in cellular and animal models of HD, but they have not been successful in clinical trials. Herein, we report that dSETDB1/ESET, a histone methyltransferase (HMT), is a mediator of mutant HTT-induced degeneration in a fly HD model. We found that nogalamycin, an anthracycline antibiotic and a chromatin remodeling drug, reduces trimethylated histone H3K9 (H3K9me3) levels and pericentromeric heterochromatin condensation by reducing the expression of Setdb1/Eset. H3K9me3-specific ChIP-on-ChIP analysis identified that the H3K9me3-enriched epigenome signatures of multiple neuronal pathways including Egr1, Fos, Ezh1, and Arc are deregulated in HD transgenic (R6/2) mice. Nogalamycin modulated the expression of the H3K9me3-landscaped epigenome in medium spiny neurons and reduced mutant HTT nuclear inclusion formation. Moreover, nogalamycin slowed neuropathological progression, preserved motor function, and extended the life span of R6/2 mice. Together, our results indicate that modulation of SETDB1/ESET and H3K9me3-dependent heterochromatin plasticity is responsible for the neuroprotective effects of nogalamycin in HD and that small compounds targeting dysfunctional histone modification and epigenetic modification by SETDB1/ESET may be a rational therapeutic strategy in HD.

[Huntington's Disease in Balearic Islands Population-Based Registry of Rare Diseases: Prevalence and Mortality during the Period 2010-2013. Spain]. / Prevalencia y mortalidad de la Enfermedad de Huntington a partir del registro poblacional de enfermedades raras de las Islas Baleares durante el período 2010-2013.

OBJECTIVE: Huntington's disease is a hereditary disease with low prevalence. The low frequency of Huntington's disease leads to its inclusion as one of the pathologies in the Registry of Rare Diseases. The Balearic Islands Population-based Registry of Rare Diseases began in 2010. Previously, there had been no prevalence or mortality data for Huntington's disease in the Balearic Islands. The aim of this study was to determine the prevalence and mortality of Huntington's disease in the Balearic Islands between 2010 and 2013. METHODS: The data sources were the Balearic Islands Population-based Registry of Rare Diseases, from which the diagnosed cases were obtained; the Balearic Islands Mortality Register, from which the deceased cases were obtained; the Balearic Islands Health Service, from which the number of Health Cards was obtained; and the National Institute for Statistics, from which population data were obtained. Prevalence and mortality rates were calculated. RESULTS: The Balearic Islands Population-based Registry of Rare Diseases registered 27 cases of Huntington's disease between 2010-2013. 63% of these were women. The period prevalence rate was 2.6 per 100,000 and the period mortality rate was 1.1 per 100,000. Menorca was the island with the highest rates, the prevalence rate was 5,9 per 100,000 and the mortality rate was 2,1 per 100,000. CONCLUSIONS: Prevalence and mortality of Huntington's disease in the Balearic Islands are low compared to similar areas.

OBJETIVO: La enfermedad de Huntington (EH) es una enfermedad hereditaria de baja prevalencia, por lo que se incluye en los registros de enfermedades raras. El registro poblacional de enfermedades raras de las Islas Baleares se inició en el año 2010. Previamente no existían datos de prevalencia y mortalidad de la EH en las Islas Baleares. El objetivo de este estudio fue determinar la prevalencia y la mortalidad de la enfermedad de Huntington en las Islas Baleares durante el periodo 2010-2013. METODOS: Se utilizaron como fuentes de información el registro poblacional de enfermedades raras de las Islas Baleares, del que se obtuvieron los casos diagnosticados, el Registro de mortalidad de las Islas Baleares, del que se obtuvieron los casos fallecidos, el registro del Servicio de Salud de las Islas Baleares del que se obtuvieron el número de tarjetas sanitarias y del Instituto Nacional de Estadística se obtuvieron los datos de población. Se calcularon las tasas de prevalencia y de mortalidad. RESULTADOS: El registro poblacional de enfermedades raras de las Islas Baleares durante el periodo 2010-2013 registró 27 casos de EH. El 63% fueron mujeres. La tasa de prevalencia fue de 2,6 por 105 y la tasa de mortalidad de 1,1 por 105. La isla de Menorca fue la más afectada con una prevalencia de 5,9 por 105 y una mortalidad de 2,1 por 105. CONCLUSIONES: La prevalencia y mortalidad de la EH en las Islas Baleares son bajas en comparación con zonas del entorno.

Prevalencia y mortalidad de la enfermedad de Huntington a partir del Registro Poblacional de Enfermedades Raras de las Isla Baleares durante el período 2010-2013 / Huntinton's disease in Balearic Islands Population-based Registry or Rare Diseases: prevalence and mortality during the perior 2010-2013. Spain

Fundamentos: La enfermedad de Huntington (EH) es una enfermedad hereditaria de baja prevalencia, por lo que se incluye en los registros de enfermedades raras. El registro poblacional de enfermedades raras de las Islas Baleares se inició en el año 2010. Previamente no existían datos de prevalencia y mortalidad de la EH en las Islas Baleares. El objetivo de este estudio fue determinar la prevalencia y la mortalidad de la enfermedad de Huntington en las Islas Baleares durante el periodo 2010-2013. Métodos: Se utilizaron como fuentes de información el registro poblacional de enfermedades raras de las Islas Baleares, del que se obtuvieron los casos diagnosticados, el Registro de mortalidad de las Islas Baleares, del que se obtuvieron los casos fallecidos, el registro del Servicio de Salud de las Islas Baleares del que se obtuvieron el número de tarjetas sanitarias y del Instituto Nacional de Estadística se obtuvieron los datos de población. Se calcularon las tasas de prevalencia y de mortalidad. Resultados: El registro poblacional de enfermedades raras de las Islas Baleares durante el periodo 2010-2013 registró 27 casos de EH. El 63% fueron mujeres. La tasa de prevalencia fue de 2,6 por 105 y la tasa de mortalidad de 1,1 por 105. La isla de Menorca fue la más afectada con una prevalencia de 5,9 por 105 y una mortalidad de 2,1 por 105. Conclusiones: La prevalencia y mortalidad de la EH en las Islas Baleares son bajas en comparación con zonas del entorno (AU)

Background: Huntington’s disease is a hereditary disease with low prevalence. The low frequency of Huntington’s disease leads to its inclusion as one of the pathologies in the Registry of Rare Diseases. The Balearic Islands Population-based Registry of Rare Diseases began in 2010. Previously, there had been no prevalence or mortality data for Huntington’s disease in the Balearic Islands. The aim of this study was to determine the prevalence and mortality of Huntington’s disease in the Balearic Islands between 2010 and 2013. Methods: The data sources were the Balearic Islands Population-based Registry of Rare Diseases, from which the diagnosed cases were obtained; the Balearic Islands Mortality Register, from which the deceased cases were obtained; the Balearic Islands Health Service, from which the number of Health Cards was obtained; and the National Institute for Statistics, from which population data were obtained. Prevalence and mortality rates were calculated. Results: The Balearic Islands Population-based Registry of Rare Diseases registered 27 cases of Huntington’s disease between 2010-2013. 63% of these were women. The period prevalence rate was 2.6 per 105 and the period mortality rate was 1.1 per 105. Menorca was the island with the highest rates, the prevalence rate was 5,9 per 105 and the mortality rate was 2,1 per 105. Conclusions: Prevalence and mortality of Huntington’s disease in the Balearic Islands are low compared to similar areas (AU)

Monitoring Huntington's Disease Mortality across a 30-Year Period: Geographic and Temporal Patterns.

BACKGROUND: Huntington's disease (HD) is a progressive neurodegenerative condition characterized by chorea, dystonia, behavioral disturbances and cognitive decline. The aim of this study is to assess temporal and spatial changes on mortality attributable to HD over 30 years in Spain. METHODS: HD data were extracted from the nationwide mortality registry for the period 1984-2013. Annual and 5-year gender- and age-specific rates adjusted for the standard European population were calculated. Geographic analysis was performed by districts from 1999 through 2013, and then estimated standardized mortality ratios (SMRs) and smoothed SMRs. RESULTS: There were 1,556 HD-related deaths across the study period. An increasing trend in age-adjusted HD mortality was in evidence, specifically from 1994 through 1998. On a year-by-year basis, age-adjusted mortality rates increased from 0.076 per 100,000 population in 1984 to 0.157 in 2013. Geographical differences among districts were evident in specific areas and in the southwest of Spain with a significantly higher HD mortality risk. CONCLUSION: HD mortality rising trends in Spain might be attributable to improvements in diagnosis leading to a rise in prevalence. Geographical variability in HD mortality could be related to regional differences in disease prevalence, health-care disparities, or other factors which call for in-depth assessment in future studies.

Huntingtons Disease Mice Infected with Toxoplasma gondii Demonstrate Early Kynurenine Pathway Activation, Altered CD8+ T-Cell Responses, and Premature Mortality.

Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a polyglutamine-repeat expansion in the huntingtin protein. Activation of the kynurenine pathway of tryptophan degradation is implicated in the pathogenesis of HD. Indoleamine-2,3-dioxygenase (IDO) catalyzes the oxidation of tryptophan to kynurenine, the first step in this pathway. The prevalent, neuroinvasive protozoal pathogen Toxoplasma gondii (T. gondii) results in clinically silent life-long infection in immune-competent individuals. T. gondii infection results in activation of IDO which provides some protection against the parasite by depleting tryptophan which the parasite cannot synthesize. The kynurenine pathway may therefore represent a point of synergism between HD and T. gondii infection. We show here that IDO activity is elevated at least four-fold in frontal cortex and striata of non-infected N171-82Q HD mice at 14-weeks corresponding to early-advanced HD. T. gondii infection at 5 weeks resulted in elevation of cortical IDO activity in HD mice. HD-infected mice died significantly earlier than wild-type infected and HD control mice. Prior to death, infected HD mice demonstrated decreased CD8+ T-lymphocyte proliferation in brain and spleen compared to wild-type infected mice. We demonstrate for the first time that HD mice have an altered response to an infectious agent that is characterized by premature mortality, altered immune responses and early activation of IDO. Findings are relevant to understanding how T. gondii infection may interact with pathways mediating neurodegeneration in HD.

High-dose 1,25-dihydroxyvitamin D supplementation elongates the lifespan of Huntington's disease transgenic mice.

Huntington's disease is an autosomal dominant progressive neurodegenerative disease, which results in a decreased quality of life and an early death. A high prevalence of vitamin D deficiency was first described in a 2013 study in patients with manifest Huntington's disease, where serum vitamin D level was found to be associated with motor capabilities of the patients. Our objective was to investigate the effect of a high-dose vitamin D3 supplementation on a transgenic mouse model of Huntington's disease. Our study was performed on N171-82Q Huntington's disease transgenic mice in age- and gender-matched groups. We collected data on the motor state and survival of the mice. The results demonstrate that though vitamin D3 had no effect on the motor performance of transgenic mice, but significantly increased the lifespan of transgenic animals (Kaplan-Meier survival curves: vehicle-supplemented group: 73 (67-94) days vs. vitamin D3-supplemented group: 101 (74-109) days, p=0.048 Mantel-Cox log rank test). Further investigations are needed to determine whether a neuroprotective or a general corroborative effect of vitamin D leads to the measured effect. Our findings support the potential influence of vitamin D deficiency on the disease course and propose that vitamin D may be an effective supplementary treatment to beneficially influence clinical features of Huntington's disease.