Clinical and genetic characteristics of late-onset Huntington's disease

Clinical and Genetic Characteristics Associated With Survival Outcome in Late-Onset Huntington's Disease in South Korea

BACKGROUND AND PURPOSE

The onset of Huntington's disease (HD) usually occurs before the age of 50 years, and the median survival time from onset is 15 years. We investigated survival in patients with late-onset HD (LoHD) (age at onset ≥60 years) and the associations of the number of mutant CAG repeats and age at onset (AAO) with survival in patients with HD.

METHODS

Patients with genetically confirmed HD at six referral centers in South Korea between 2000 and 2020 were analyzed retrospectively. Baseline demographic, clinical, and genetic characteristics and the survival status as at December 2020 were collected.

RESULTS

Eighty-seven patients were included, comprising 26 with LoHD (AAO=68.77±5.91 years, mean±standard deviation; 40.54±1.53 mutant CAG repeats) and 61 with common-onset HD (CoHD) (AAO=44.12±8.61 years, 44.72±4.27 mutant CAG repeats). The ages at death were 77.78±7.46 and 53.72±10.86 years in patients with LoHD and CoHD, respectively (p<0.001). The estimated survival time was 15.21±2.49 years for all HD patients, and 10.74±1.95 and 16.15±2.82 years in patients with LoHD and CoHD, respectively. More mutant CAG repeats and higher AAO were associated with shorter survival (hazard ratio [HR]=1.05, 95% confidence interval [CI]=1.01-1.09, p=0.019; and HR=1.17, 95% CI=1.03-1.31, p=0.013; respectively) for all HD patients. The LoHD group showed no significant factors associated with survival after disease onset, whereas the number of mutant CAG repeats had a significant effect (HR=1.12, 95% CI=1.01-1.23, p=0.034) in the CoHD group.

CONCLUSIONS

Survival after disease onset was shorter in patients with LoHD than in those with CoHD. More mutant CAG repeats and higher AAO were associated with shorter survival in patients with HD.

Physiological and pathological consequences of exosomes at the blood-brain-barrier interface

Blood-brain barrier (BBB) interface with multicellular structure controls strictly the entry of varied circulating macromolecules from the blood-facing surface into the brain parenchyma. Under several pathological conditions within the central nervous system, the integrity of the BBB interface is disrupted due to the abnormal crosstalk between the cellular constituents and the recruitment of inflammatory cells. Exosomes (Exos) are nano-sized extracellular vesicles with diverse therapeutic outcomes. These particles transfer a plethora of signaling molecules with the potential to modulate target cell behavior in a paracrine manner. Here, in the current review article, the therapeutic properties of Exos and their potential in the alleviation of compromised BBB structure were discussed. Video Abstract.

Application Value of Serum Neurofilament Light Protein for Disease Staging in Huntington's Disease

BACKGROUND

Neurofilament light protein (NfL) has been proven to be a sensitive biomarker for Huntington's disease (HD). However, these studies did not include HD patients at advanced stages or with larger CAG repeats (>50), leading to a knowledge gap of the characteristics of NfL.

METHODS

Serum NfL (sNfL) levels were quantified using an ultrasensitive immunoassay. Participants were assessed by clinical scales and 7.0 T magnetic resonance imaging. Longitudinal samples and clinical data were obtained.

RESULTS

Baseline samples were available from 110 controls, 90 premanifest HD (pre-HD) and 137 HD individuals. We found levels of sNfL significantly increased in HD compared to pre-HD and controls (both P < 0.0001). The increase rates of sNfL were differed by CAG repeat lengths. However, there was no difference in sNfL levels in manifest HD from early to late stages. In addition, sNfL levels were associated with cognitive measures in pre-HD and manifest HD group, respectively. The increased levels of sNfL were also closely related to microstructural changes in white matter. In the longitudinal analysis, baseline sNfL did not correlate with subsequent clinical function decline. Random forest analysis revealed that sNfL had good power for predicting disease onset.

CONCLUSIONS

Although sNfL levels are independent of disease stages in manifest HD, it is still an optimal indicator for predicting disease onset and has potential use as a surrogate biomarker of treatment effect in clinical trials. © 2023 International Parkinson and Movement Disorder Society.

Chorea in the Elderly: A Differential Diagnosis and Case Report of Late-Onset Huntington's Disease in an Octogenarian

The term "senile chorea" was previously used to describe cases of insidious onset chorea in elderly patients who lacked family history of chorea. However, many of these patients have an identifiable etiology for their chorea. In this article, we discuss a case of generalized, insidious onset chorea in an 89-year-old man and apply a systematic diagnostic approach to chorea in the elderly to arrive at a diagnosis of late-onset Huntington's disease. He is to our knowledge the second oldest case of late-onset Huntington's disease reported in the literature and his case lends support to the expanding phenotype of Huntington's disease.

Clinical and genetic characteristics of late-onset Huntington's disease in a large European cohort

Background and purpose

Huntington's disease (HD) is an autosomal dominant condition caused by CAG‐triplet repeat expansions. CAG‐triplet repeat expansion is inversely correlated with age of onset in HD and largely determines the clinical features. The aim of this study was to examine the phenotypic and genotypic correlates of late‐onset HD (LoHD) and to determine whether LoHD is a more benign expression of HD.

Methods

This was a retrospective observational study of 5053 White European HD patients from the ENROLL‐HD database. Sociodemographic, genetic and phenotypic variables at baseline evaluation of subjects with LoHD, common‐onset HD (CoHD) and young‐onset HD (YoHD) were compared. LoHD subjects were compared with healthy subjects (HS) aged ≥60 years. Differences between the CoHD and LoHD groups were also explored in subjects with 41 CAG triplets, a repeat number in the lower pathological expansion range associated with wide variability in age at onset.

Results

Late‐onset HD presented predominantly as motor‐onset disease, with a lower prevalence of both psychiatric history and current symptomatology. Absent/unknown HD family history was significantly more common in the LoHD group (31.2%) than in the other groups. The LoHD group had more severe motor and cognitive deficits than the HS group. Subjects with LoHD and CoHD with 41 triplets in the larger allele were comparable with regard to cognitive impairment, but those with LoHD had more severe motor disorders, less problematic behaviors and more often an unknown HD family history.

Conclusions

It is likely that cognitive disorders and motor symptoms of LoHD are at least partly age‐related and not a direct expression of the disease. In addition to CAG‐triplet repeat expansion, future studies should investigate the role of other genetic and environmental factors in determining age of onset.

The regulatory roles of microRNAs toward pathogenesis and treatments in Huntington's disease

Huntington's disease (HD) is one of neurodegenerative diseases, and is defined as a monogenetic disease due to the mutation of Huntingtin gene. This disease affects several cellular functions in neurons, and further influences motor and cognitive ability, leading to the suffering of devastating symptoms in HD patients. MicroRNA (miRNA) is a non-coding RNA, and is responsible for gene regulation at post-transcriptional levels in cells. Since one miRNA targets to several downstream genes, it may regulate different pathways simultaneously. As a result, it raises a potential therapy for different diseases using miRNAs, especially for inherited diseases. In this review, we will not only introduce the update information of HD and miRNA, but also discuss the development of potential miRNA-based therapy in HD. With the understanding toward the progression of miRNA studies in HD, we anticipate it may provide an insight to treat this devastating disease, even applying to other genetic diseases.

Timing and Impact of Psychiatric, Cognitive, and Motor Abnormalities in Huntington Disease

Objective

To assess the prevalence, timing, and functional impact of psychiatric, cognitive, and motor abnormalities in Huntington disease (HD) gene carriers, we analyzed retrospective clinical data from individuals with manifest HD.

Methods

Clinical features of patients with HD were analyzed for 6,316 individuals in an observational study of the European Huntington's Disease Network (REGISTRY) from 161 sites across 17 countries. Data came from clinical history and the patient-completed Clinical Characteristics Questionnaire that assessed 8 symptoms: motor, cognitive, apathy, depression, perseverative/obsessive behavior, irritability, violent/aggressive behavior, and psychosis. Multiple logistic regression was used to analyze relationships between symptoms and functional outcomes.

Results

The initial manifestation of HD is increasingly likely to be motor and less likely to be psychiatric as age at presentation increases and is independent of pathogenic CAG repeat length. The Clinical Characteristics Questionnaire captures data on nonmotor symptom prevalence that correlate specifically with validated clinical measures. Psychiatric and cognitive symptoms are common in HD gene carriers, with earlier onsets associated with longer CAG repeats. Of patients with HD, 42.4% reported at least 1 psychiatric or cognitive symptom before motor symptoms, with depression most common. Each nonmotor symptom was associated with significantly reduced total functional capacity scores.

Conclusions

Psychiatric and cognitive symptoms are common and functionally debilitating in HD gene carriers. They require recognition and targeting with clinical outcome measures and treatments. However, because it is impossible to distinguish confidently between nonmotor symptoms arising from HD and primary psychiatric disorders, particularly in younger premanifest patients, nonmotor symptoms should not be used to make a clinical diagnosis of HD.

Trial Registration Information

ClinicalTrials.gov Identifier: NCT01590589

Genetic epidemiological characteristics of a Hungarian subpopulation of patients with Huntington's disease

Background

Recent advances in therapeutic options may prevent deterioration related to Huntington’s disease (HD), even at the pre-symptomatic stage. Be that as it may, a well-characterized patient population is essential for screening and monitoring outcome. Accordingly, the aim of this study was to describe the characteristics of a Hungarian subpopulation of HD patients and mutation carriers diagnosed at the University of Szeged.

Methods

We conducted a search for International Classification of Diseases (ICD) code G10H0 in the local medical database for the period of 1 January 1998 to 31 December 2018.

Results

We identified 90 HD cases (male: 45, female: 45) and 34 asymptomatic carriers (male: 15, female: 19). The median age of onset was 45 years (range: 16–79). There were 3 cases of juvenile onset (3.3%), and 7 of late disease onset (7.8%). The median repeat length was 43 (range: 36–70) for the pathological and 19 for the non-pathological alleles (range: 9–35). 17.5% of the pathological alleles were in the decreased penetrance range, while 7% of non-pathological alleles were intermediate.

Conclusions

The genetic and clinical features of the population examined in the present study were in line with the previous Hungarian study, as well as with international literature. The exceptions were the higher ratio of reduced penetrance and intermediate alleles.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02089-9.

Late-onset Huntington disease: An Italian cohort

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by a CAG expansion greater than 35 triplets in the IT-15 gene, with a clinical onset usually in the forties. Late-onset form of HD is defined as disease onset after the age of 59 years. The aim of the present study is to investigate the clinical-demographic features of Late-onset HD population (LoHD) in comparison to Classic-onset patients (CoHD). We analyzed a well-characterized Italian cohort of 127 HD patients, identifying 25.2% of LoHD cases. The mean age of onset was 65.9 and the mean length of pathological allele was 42.2. The 53.1% of LoHD patients had no family history of HD. No significant differences were observed in terms of gender, type of symptoms at disease onset, and clinical performance during the follow-up visits. The non-pathological allele resulted longer among LoHD patients. There is evidence that longer non-pathological allele is associated with a higher volume of basal ganglia, suggesting a possible protective role even in the onset of HD. In conclusion, LoHD patients in this Italian cohort were frequent, representing a quarter of total cases, and showed clinical features comparable to CoHD subjects. Due to the small sample size, further studies are needed to evaluate the influence of non-pathological alleles on disease onset.

The future of genomics in Ireland - focus on genomics for health

Genomics is revolutionizing biomedical research, medicine and healthcare globally in academic, public and industry sectors alike. Concrete examples around the world show that huge benefits for patients, society and economy can be accrued through effective and responsible genomic research and clinical applications. Unfortunately, Ireland has fallen behind and needs to act now in order to catch up. Here, we identify key issues that have resulted in Ireland lagging behind, describe how genomics can benefit Ireland and its people and outline the measures needed to make genomics work for Ireland and Irish patients. There is now an urgent need for a national genomics strategy that enables an effective, collaborative, responsible, well-regulated, and patient centred environment where genome research and clinical genomics can thrive.  We present eight recommendations that could be the pillars of a national genomics health strategy.

Age of onset and behavioral manifestations in Huntington's disease: An Enroll-HD cohort analysis

Huntington's disease is associated with motor, cognitive and behavioral dysfunction. Behavioral symptoms may present before, after, or simultaneously with clinical disease manifestation. The relationship between age of onset and behavioral symptom presentation and severity was explored using the Enroll-HD database. Manifest individuals (n = 4469) were initially divided into three groups for preliminary analysis: early onset (<30 years; n = 479); mid-adult onset (30-59 years; n = 3478); and late onset (>59 years; n = 512). Incidence of behavioral symptoms reported at onset was highest in those with early onset symptoms at 26% (n = 126), compared with 19% (n = 678) for mid-adult onset and 11% (n = 56) for late onset (P < 0.0001). Refined analysis, looking across the continuum of ages rather than between categorical subgroups found that a one-year increase in age of onset was associated with a 5.6% decrease in the odds of behavioral symptoms being retrospectively reported as the presenting symptom (P < 0.0001). By the time of study enrollment, the odds of reporting severe behavioral symptoms decreased by 5.5% for each one-year increase in reported age of onset. Exploring environmental, genetic and epigenetic factors that affect age of onset and further characterizing types and severity of behavioral symptoms may improve treatment and understanding of Huntington's disease's impact on affected individuals.

Influence of Age of Onset on Huntington's Disease Phenotype

Background

Older patients with Huntington's disease (HD) are often thought to have a slower progressing disease course with less behavioral symptoms than younger patients. However, phenotypic differences based on age of onset have not been well characterized in a large HD population. This study will determine the difference in manifestations and disease progression between patients with young, typical, and late onset adult HD at different stages of disease.

Methods

Data obtained from Enroll-HD. Adults with manifest HD were included. Age groups were defined as young onset (YO: 20-29 years), typical onset (TO: 30-59 years), and late onset (LO: 60+ years). Subjects were categorized by TFC score, from Stage I (least severe) to Stage V (most severe). Motor, cognitive, and behavioral symptoms were analyzed. Descriptive statistics and Bonferroni p-value correction for pairwise comparison were calculated.

Results

7,311 manifest HD participants were included (612 YO, 5,776 TO, and 923 LO). The average decline in TFC score from baseline to second visit (1.5-2.5 years) was significantly faster for YO (-1.75 points) compared to TO (-1.23 points, p = 0.0105) or LO (-0.97 points, p = 0.0017). Motor deficits were worse for LO participants at early stages of HD, and worse for YO participants at advanced stages. YO and TO participants had greater burden of behavioral symptoms at early stages of disease compared to LO.

Discussion

YO is predictive of a faster functional decline for adults with HD when compared to those with TO and LO. Motor and behavioral manifestations differ based on age of onset.

Highlights

This study compares HD manifestations while controlling for disease severity, detailing robust phenotypic differences by age of onset alone. These findings have implications for the clinical management of HD symptoms and have the possibility to improve prognostic and treatment precision.

Late-onset Huntington's disease with 40-42 CAG expansion

INTRODUCTION

Huntington's disease (HD) is a rare autosomal dominant neurodegenerative disorder caused by a CAG expansion greater than 35 in the IT-15 gene. There is an inverse correlation between the number of pathological CAG and the age of onset. However, CAG repeats between 40 and 42 showed a wider onset variation. We aimed to investigate potential clinical differences between patients with age at onset ≥ 60 years (late onset-HD) and patients with age at onset between 30 and 59 years (common-onset HD) in a cohort of patients with the same CAG expansions (40-42).

METHODS

A retrospective analysis of 66 HD patients with 40-41-42 CAG expansion was performed. Patients were investigated with the Unified Huntington's Disease Rating Scale (subitems I-II-III and Total Functional Capacity, Functional Assessment and Stage of Disease). Data were analysed using χ2, Fisher's test, t test and Pearson's correlation coefficient. GENMOD analysis and Kaplan-Meier analysis were used to study the disease progression.

RESULTS

The age of onset ranged from 39 to 59 years in the CO subgroup, whereas the LO subgroup showed an age of onset from 60 to 73 years. No family history was reported in 31% of the late-onset in comparison with 20% in common-onset HD (p = 0.04). No difference emerged in symptoms of onset, in clinical manifestations and in progression of disease between the two groups.

CONCLUSION

There were no clinical differences between CO and LO subgroups with 40-42 CAG expansion. There is a need of further studies on environmental as well genetic variables modifying the age at onset.