Patient experiences of receiving a diagnosis of hypermobile Ehlers-Danlos syndrome.

Hypermobile Ehlers-Danlos syndrome (hEDS) presents with a wide range of clinical symptoms and comorbidities that impact quality of life. The diagnosis is challenging and often delayed due to the heterogeneity of the disease and lack of diagnostic biomarkers, which adds to the disease burden by affecting patients' psychosocial adaptation and overall well-being. Previous studies have revealed that healthcare professionals and the public have a limited understanding and familiarity with the condition, which leads to disapproval and skepticism that greatly impact patients' social spheres and welfare. While physical manifestations have been widely discussed, the psychosocial impact and the importance of receiving a diagnosis have not been fully studied in the current literature. This survey study investigated the impact of diagnosis in hEDS patients, selected from the University of Miami's hEDS registry. Survey questions were formulated based on clinical expertise and literature review. Descriptive statistics, Mann-Whitney test, and Spearman's correlation were used for data analysis. The median age at symptom presentation was 10 years, with a median gap of 4 years before the initial medical evaluation. On average, it took 10 years to receive a diagnosis of hEDS. Nearly all participants (95.2%) expressed receiving a diagnosis as "important" or "highly important," with 81.9% agreeing that it helped them cope with their condition better, 76.8% could better manage their symptoms, and felt more in control of their long-term care. Participants mostly had a positive emotional reaction and experienced an improvement in the support they were receiving from their caregivers and healthcare providers after receiving a diagnosis of hEDS. This study demonstrates that receiving a diagnosis could positively impact the patient's support, quality of care, and overall well-being.

Validation of a suspicion index to identify patients at risk for hereditary angioedema.

Background: Hereditary angioedema (HAE) is a genetic condition characterized by dysregulation of the contact (kallikrein-bradykinin) pathway, leading to recurrent episodes of angioedema. Objective: This project sought to determine whether a suspicion index screening tool using electronic health record (EHR) data can identify patients with an increased likelihood of a diagnosis of HAE. Methods: A suspicion index screening tool for HAE was created and validated by using known patients with HAE from the medical literature as well as positive and negative controls from HAE-focused centers. Through the use of key features of medical and family history, a series of logistic regression models for 5 known genetic causes of HAE were created. Top variables populated the digital suspicion scoring system and were run against deidentified EHR data. Patients at 2 diverse sites were categorized as being at increased, possible, or no increased risk of HAE. Results: Prediction scoring using the strongest 13 variables on the "real-world" EHR-positive control data identified all but 1 patient with C1 inhibitor deficiency and patient with non-C1 inhibitor deficiency without false-positive results. The 2 missed patients had no documented family history of HAE in their EHR. When the prediction scoring variables were expanded to 25, the screening algorithm approached 100% sensitivity and specificity. The 25-variable algorithm run on general population EHR data identified 26 patients at the medical centers as being at increased risk for HAE. Conclusions: These results suggest that development, validation, and implementation of suspicion index screening tools can be useful to aid providers in identifying patients with rare genetic conditions.

Very-Long-Chain Acyl-CoA Dehydrogenase Deficiency: Family Impact and Perspectives.

Very-Long-Chain Acyl-CoA Dehydrogenase Deficiency (VLCADD) is a fatty acid oxidation disorder characterized by the decreased ability of the enzyme very-long-chain acyl-CoA dehydrogenase to break down fatty acids with 14 to 20-long carbon chains. The resulting clinical manifestations are variable in severity and include hypoketotic hypoglycemia, rhabdomyolysis, and cardiomyopathy. Treatment can consist of limiting the dietary intake of long-chain fatty acids, the prevention of fasting, and the supplementation of medium-chain fats. This study, conducted in the context of a 5-year long-term follow-up on VLCADD, evaluates how the diagnosis of this fatty acid disorder impacts the family, specifically as it relates to the medical diet and barriers to care. Caregivers (n = 10) of individuals with VLCADD responded to a survey about how VLCADD potentially impacts their family. The review included the clinical outcomes of the patients (n = 11), covering instances of rhabdomyolysis, cardiomyopathy, and hospitalizations related to VLCADD. Families affected by VLCADD experience barriers to care, including difficulties with finances, ability to work, and access to nutrition.

Thyroid disease in cervical dystonia.

There are many possible etiologies for cervical dystonia (CD), but a cause cannot be identified in most cases. Most recent attention has focused on genetic causes, although a few prior studies have highlighted autoimmune mechanisms instead. Because autoimmune disorders frequently co-exist, the current study evaluated the hypothesis that autoimmune disorders might be more common in CD than neurological controls. The frequency of 32 common autoimmune disorders was evaluated using a systematic survey comparing 300 subjects with CD with 391 neurological controls. The frequency of thyroid disease was significantly higher in CD (20%) compared with controls (6%). Regression analyses that accounted for age and sex revealed an odds ratio of 4.5 (95% CI 2.5-8.1, p < 0.001). All other autoimmune disorders occurred with similar frequencies in CD and controls. Although these studies do not establish a mechanistic link between CD and autoimmune disease, they suggest the need for further attention to a potential relationship, and more specifically with thyroid disease.

Genetic Referral Patterns and Responses to Clinical Scenarios: A Survey of Primary Care Providers and Clinical Geneticists.

INTRODUCTION: Primary care physicians (PCPs) are considered the gatekeepers of genetic services, but they often underutilize or inappropriately utilize such services, leading to lack of early treatment, incorrect diagnoses, and unnecessary procedures. This study aims to delineate PCP referral patterns, including the frequency of, motivators for, and barriers to genetic referrals and testing in the present landscape of genomics. METHODS: A 34-item online survey was distributed to PCPs in the United States (US). PCP demographics, practice characteristics, and referral patterns, motivators, and barriers were analyzed. Six hypothetical clinical scenarios included in the survey also were presented to a cohort of clinical geneticists. We calculated PCPs' rates of ordering genetic tests and of referral to genetics services in the past year. Rates and responses to clinical scenarios were compared based on respondents' personal and practice characteristics. RESULTS: A total of 95 PCPs and 25 clinical geneticists participated. Among the PCPs, 79% reported referring and 50% reported ordering genetic testing in the last year. PCPs with genetic counselors (GCs) in their clinic referred at significantly higher rates than those without (P = .008). White PCPs referred at significantly higher rates compared to Black or African American PCPs (P = .009). The most commonly reported motivators for referring patients to genetic services were preference for specialist coordination, lack of knowledge, and family's desire for risk information. The most commonly reported barriers were patient refusal, provider concerns about costs to patients, and uncertainty of when a genetic referral is appropriate. In response to clinical scenarios, clinical geneticists were in agreement about the need for genetic testing or referral for 2 of the scenarios. For these 2 scenarios, only 48% and 71% of PCPs indicated that they would offer genetic testing or referral, respectively. CONCLUSIONS: Responses to clinical scenarios suggest that it is not clear to PCPs when referrals or testing are needed. Collaboration with GCs is one approach to reducing barriers to and improving PCPs' utilization of genetic services. Clear guidelines from clinical geneticists may help facilitate appropriate use of genetics services by PCPs. Additional research is needed to further describe barriers that PCPs face in genetic testing/referrals.

Spinocerebellar Ataxia Patient Perceptions Regarding Reproductive Options.

BACKGROUND: In vitro fertilization with preimplantation genetic testing is a growing reproductive option for people who want to avoid passing a single-gene condition on to their offspring. The spinocerebellar ataxias are a group of rare, autosomal-dominant neurodegenerative disorders which are strong candidates for the use of this technology. OBJECTIVES: This study aimed to assess knowledge of genetic risk and perceptions of reproductive options in individuals with a diagnosis of spinocerebellar ataxia. METHODS: We administered an online survey to U.S. residents of reproductive age who have been clinically or genetically diagnosed with spinocerebellar ataxia. We assessed their understanding of inheritance and their reproductive opinions. RESULTS: Of 94 participants, 70.2% answered all four inheritance questions correctly. The majority felt they could describe each reproductive option except prenatal diagnosis. Individuals were most interested in in vitro fertilization with preimplantation genetic testing: 48.4% (45 of 93) said they would consider it. They were least interested in prenatal diagnosis and donated embryos or gametes. Having spinocerebellar ataxia with anticipation and choosing inheritance risk as an important factor were both significantly associated with interest in preimplantation genetic testing. Choosing religion/morality as an important factor was associated with less interest in preimplantation genetic testing and prenatal diagnosis. CONCLUSIONS: Our population displayed basic knowledge of inheritance risk, and the majority wanted to avoid having affected children. Consistent with literature for other autosomal-dominant adult-onset conditions, individuals showed a preference for preimplantation genetic testing. Health care providers should continue to educate patients about reproductive options and their risks and limitations.

The Changing Age of Individuals Seeking Presymptomatic Genetic Testing for Huntington Disease.

Huntington disease (HD) is a progressive neurodegenerative disorder. Presymptomatic genetic testing allows at-risk individuals to clarify their risk status. Understanding the characteristics and motivations of individuals seeking HD presymptomatic genetic testing better equips genetic counselors and other healthcare professionals to provide comprehensive and personalized care. The aims of this study were to (1) determine whether the average age when individuals seek presymptomatic HD genetic testing has decreased over time, (2) assess motivations for seeking testing, (3) explore whether there is a relationship between age and motivations, and (4) explore genetic counselors' perceptions of the shift in age. Data from the US HD testing centers (N = 4) were analyzed. A small but statistically significant decrease in age of individuals seeking presymptomatic testing was observed (p = 0.045). HD community members (N = 77) were surveyed regarding presymptomatic testing motivations. Younger individuals were more likely than older individuals to cite "To learn whether or not you would develop HD" and "To make choices about further education or a career" compared to older individuals (p < 0.05). Conversely, older individuals more frequently cited "To give children a better idea of their risk" (p < 0.002). Sixteen percent of genetic counselors surveyed (6/37) perceived a change in age of testing. All of these respondents had provided HD testing for ten or more years and anecdotally believed the age at testing has decreased over time. Study results help providers personalize counseling based on patient's age and serve as a starting point for more research into the relationship between age at testing and motivations for testing.

Clinical and demographic characteristics related to onset site and spread of cervical dystonia.

BACKGROUND: Clinical characteristics of isolated idiopathic cervical dystonia such as onset site and spread to and from additional body regions have been addressed in single-site studies with limited data and incomplete or variable dissociation of focal and segmental subtypes. The objectives of this study were to characterize the clinical characteristics and demographics of isolated idiopathic cervical dystonia in the largest standardized multicenter cohort. METHODS: The Dystonia Coalition, through a consortium of 37 recruiting sites in North America, Europe, and Australia, recruited 1477 participants with focal (60.7%) or segmental (39.3%) cervical dystonia on examination. Clinical and demographic characteristics were evaluated in terms of the body region of dystonia onset and spread. RESULTS: Site of dystonia onset was: (1) focal neck only (78.5%), (2) focal onset elsewhere with later segmental spread to neck (13.3%), and (3) segmental onset with initial neck involvement (8.2%). Frequency of spread from focal cervical to segmental dystonia (22.8%) was consistent with prior reports, but frequency of segmental onset with initial neck involvement was substantially higher than the 3% previously reported. Cervical dystonia with focal neck onset, more than other subtypes, was associated with spread and tremor of any type. Sensory tricks were less frequent in cervical dystonia with segmental components, and segmental cervical onset occurred at an older age. CONCLUSIONS: Subgroups had modest but significant differences in the clinical characteristics that may represent different clinical entities or pathophysiologic subtypes. These findings are critical for design and implementation of studies to describe, treat, or modify disease progression in idiopathic isolated cervical dystonia. © 2016 International Parkinson and Movement Disorder Society.

Clinical and genetic features of cervical dystonia in a large multicenter cohort.

OBJECTIVE: To characterize the clinical and genetic features of cervical dystonia (CD). METHODS: Participants enrolled in the Dystonia Coalition biorepository (NCT01373424) with initial manifestation as CD were included in this study (n = 1,000). Data intake included demographics, family history, and the Global Dystonia Rating Scale. Participants were screened for sequence variants (SVs) in GNAL, THAP1, and Exon 5 of TOR1A. RESULTS: The majority of participants were Caucasian (95%) and female (75%). The mean age at onset and disease duration were 45.5 ± 13.6 and 14.6 ± 11.8 years, respectively. At the time of assessment, 68.5% had involvement limited to the neck, shoulder(s), and proximal arm(s), whereas 47.4% had dystonia limited to the neck. The remaining 31.5% of the individuals exhibited more extensive anatomical spread. A head tremor was noted in 62% of the patients. Head tremor and laryngeal dystonia were more common in females. Psychiatric comorbidities, mainly depression and anxiety, were reported by 32% of the participants and were more common in females. Family histories of dystonia, parkinsonian disorder, and tremor were present in 14%, 11%, and 29% of the patients, respectively. Pathogenic or likely pathogenic SVs in THAP1, TOR1A, and GNAL were identified in 8 participants (0.8%). Two individuals harbored novel missense SVs in Exon 5 of TOR1A. Synonymous and noncoding SVs in THAP1 and GNAL were identified in 4% of the cohort. CONCLUSIONS: Head tremor, laryngeal dystonia, and psychiatric comorbidities are more common in female participants with CD. Coding and noncoding variants in GNAL, THAP1, and TOR1A make small contributions to the pathogenesis of CD.

Botulinum toxin treatment failures in cervical dystonia: causes, management, and outcomes.

Botulinum toxin (BoNT) is highly effective in the treatment of cervical dystonia (CD), yet a significant proportion of patients report low levels of satisfaction following treatment and fail to follow up for repeated treatments. The goal of this study was to determine the reasons that some patients have unsatisfactory responses. A total of 35 subjects who came to our center requesting alternative treatments due to unsatisfactory responses following BoNT treatment for CD were evaluated. Included were 26 women and 9 men with an average age of 57.1 years (range 25-82 years), and an average duration of illness of 12.5 years (range 1-55 years). Details of unsatisfactory BoNT treatments were methodically collected by a movement specialist using a standardized intake form, including provider subspecialty, product used, the number of satisfactory or unsatisfactory trials, doses given, specific muscles treated, the use of electromyographic guidance, side effects, and tests of resistance. The specialist then provided repeat treatments if indicated, and followed each case until the reasons for unsatisfactory outcomes could be determined. Multiple reasons for unsatisfactory outcomes were found. They included suboptimal BoNT doses, suboptimal muscle targeting, intolerable side effects, complex movement patterns, discordant perceptions, and incorrect diagnoses. Only one patient was functionally resistant to BoNT. Of 32 subjects who received repeat BoNT treatments, 25 (78 %) achieved satisfactory responses after revision of the original treatment plan. These results indicate that the majority of unsatisfactory responses to BoNT treatment of CD were caused by correctible factors and imply a need for improved education regarding optimal treatment methods.

Clinimetric testing of the comprehensive cervical dystonia rating scale.

INTRODUCTION: The aim of this study was to test the clinimetric properties of the Comprehensive Cervical Dystonia Rating Scale. This is a modular scale with modifications of the Toronto Western Spasmodic Torticollis Rating Scale (composed of three subscales assessing motor severity, disability, and pain) now referred to as the revised Toronto Western Spasmodic Torticollis Scale-2; a newly developed psychiatric screening instrument; and the Cervical Dystonia Impact Profile-58 as a quality of life measure. METHODS: Ten dystonia experts rated subjects with cervical dystonia using the comprehensive scale. Clinimetric techniques assessed each module of the scale for reliability, item correlation, and factor structure. RESULTS: There were 208 cervical dystonia patients (73% women; age, 59 ± 10 years; duration, 15 ± 12 years). Internal consistency of the motor severity subscale was acceptable (Cronbach's alpha = 0.57). Item to total correlations showed that elimination of items with low correlations (<0.20) increased alpha to 0.71. Internal consistency estimates for the subscales for disability and pain were 0.88 and 0.95, respectively. The psychiatric screening scale had a Cronbach's alpha of 0.84 and satisfactory item to total correlations. When the subscales of the Toronto Western Spasmodic Torticollis Scale-2 were combined with the psychiatric screening scale, Cronbach's alpha was 0.88, and construct validity assessment demonstrated four rational factors: motor; disability; pain; and psychiatric disorders. The Cervical Dystonia Impact Profile-58 had an alpha of 0.98 and its construction was validated through a confirmatory factor analysis. CONCLUSIONS: The modules of the Comprehensive Cervical Dystonia Rating Scale are internally consistent with a logical factor structure.

Potential mechanisms for low uric acid in Parkinson disease.

Several epidemiologic studies have described an association between low serum uric acid (UA) and Parkinson disease (PD). Uric acid is a known antioxidant, and one proposed mechanism of neurodegeneration in PD is oxidative damage of dopamine neurons. However, other complex metabolic pathways may contribute. The purpose of this study is to elucidate potential mechanisms of low serum UA in PD. Subjects who met diagnostic criteria for definite or probable PD (n = 20) and controls (n = 20) aged 55-80 years were recruited. Twenty-four hour urine samples were collected from all participants, and both uric acid and allantoin were measured and corrected for body mass index (BMI). Urinary metabolites were compared using a twoway ANOVA with diagnosis and sex as the explanatory variables. There were no significant differences between PD and controls for total UA (p = 0.60), UA corrected for BMI (p = 0.37), or in the interaction of diagnosis and sex on UA (p = 0.24). Similarly, there were no significant differences between PD and controls for allantoin (p = 0.47), allantoin corrected for BMI (p = 0.57), or in the interaction of diagnosis and sex on allantoin (p = 0.78). Allantoin/UA ratios also did not significantly differ by diagnosis (p = 0.99). Our results imply that low serum UA in PD may be due to an intrinsic mechanism that alters the homeostatic set point for serum UA in PD, and may contribute to relatively lower protection against oxidative damage. These findings provide indirect support for neuroprotection trials aimed at raising serum UA.

Diagnostic Delays in Spasmodic Dysphonia: A Call for Clinician Education.

PURPOSE: Spasmodic dysphonia (SD) is a rare but often debilitating disease. Due to lack of awareness among practitioners and lack of well-defined diagnostic criteria, it can be difficult for patients with SD to receive a diagnosis and subsequent treatment. There is currently no literature documenting the efficacy of the medical community in recognizing and diagnosing this disorder. We aimed to quantify the patients' experiences with obtaining a diagnosis of SD. METHODS: One hundred seven consecutive patients with SD completed questionnaires about their experiences with SD. Patients were recruited either during outpatient laryngology visits or during participation in a National Institutes of Health funded study investigating SD. RESULTS: It took patients an average of 4.43 years (53.21 months) to be diagnosed with SD after first going to a physician with vocal symptoms. Patients had to see an average of 3.95 physicians to receive a diagnosis of SD. Patients (31.4%) had been prescribed medications other than botulinum toxin to treat their symptoms. Patients (30%) attempted alternative therapies for treatment of SD, such as chiropractor or dietary modification. CONCLUSIONS: Despite advances in diagnostic modalities in medicine, the diagnosis of SD still remains elusive. Objective criteria for the diagnosis of SD and increased clinician education are warranted to address this diagnostic delay.

A multiancestral genome-wide exome array study of Alzheimer disease, frontotemporal dementia, and progressive supranuclear palsy.

IMPORTANCE: Previous studies have indicated a heritable component of the etiology of neurodegenerative diseases such as Alzheimer disease (AD), frontotemporal dementia (FTD), and progressive supranuclear palsy (PSP). However, few have examined the contribution of low-frequency coding variants on a genome-wide level. OBJECTIVE: To identify low-frequency coding variants that affect susceptibility to AD, FTD, and PSP. DESIGN, SETTING, AND PARTICIPANTS: We used the Illumina HumanExome BeadChip array to genotype a large number of variants (most of which are low-frequency coding variants) in a cohort of patients with neurodegenerative disease (224 with AD, 168 with FTD, and 48 with PSP) and in 224 control individuals without dementia enrolled between 2005-2012 from multiple centers participating in the Genetic Investigation in Frontotemporal Dementia and Alzheimer's Disease (GIFT) Study. An additional multiancestral replication cohort of 240 patients with AD and 240 controls without dementia was used to validate suggestive findings. Variant-level association testing and gene-based testing were performed. MAIN OUTCOMES AND MEASURES: Statistical association of genetic variants with clinical diagnosis of AD, FTD, and PSP. RESULTS: Genetic variants typed by the exome array explained 44%, 53%, and 57% of the total phenotypic variance of AD, FTD, and PSP, respectively. An association with the known AD gene ABCA7 was replicated in several ancestries (discovery P=.0049, European P=.041, African American P=.043, and Asian P=.027), suggesting that exonic variants within this gene modify AD susceptibility. In addition, 2 suggestive candidate genes, DYSF (P=5.53×10(-5)) and PAXIP1 (P=2.26×10(-4)), were highlighted in patients with AD and differentially expressed in AD brain. Corroborating evidence from other exome array studies and gene expression data points toward potential involvement of these genes in the pathogenesis of AD. CONCLUSIONS AND RELEVANCE: Low-frequency coding variants with intermediate effect size may account for a significant fraction of the genetic susceptibility to AD and FTD. Furthermore, we found evidence that coding variants in the known susceptibility gene ABCA7, as well as candidate genes DYSF and PAXIP1, confer risk for AD.

Secured web-based video repository for multicenter studies.

BACKGROUND: We developed a novel secured web-based dystonia video repository for the Dystonia Coalition, part of the Rare Disease Clinical Research network funded by the Office of Rare Diseases Research and the National Institute of Neurological Disorders and Stroke. A critical component of phenotypic data collection for all projects of the Dystonia Coalition includes a standardized video of each participant. We now describe our method for collecting, serving and securing these videos that is widely applicable to other studies. METHODS: Each recruiting site uploads standardized videos to a centralized secured server for processing to permit website posting. The streaming technology used to view the videos from the website does not allow downloading of video files. With appropriate institutional review board approval and agreement with the hosting institution, users can search and view selected videos on the website using customizable, permissions-based access that maintains security yet facilitates research and quality control. RESULTS: This approach provides a convenient platform for researchers across institutions to evaluate and analyze shared video data. We have applied this methodology for quality control, confirmation of diagnoses, validation of rating scales, and implementation of new research projects. CONCLUSIONS: We believe our system can be a model for similar projects that require access to common video resources.

Development of the Comprehensive Cervical Dystonia Rating Scale: Methodology.

We present the methodology utilized for development and clinimetric testing of the Comprehensive Cervical Dystonia (CD) Rating scale, or CCDRS. The CCDRS includes a revision of the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS-2), a newly developed psychiatric screening tool (TWSTRS-PSYCH), and the previously validated Cervical Dystonia Impact Profile (CDIP-58). For the revision of the TWSTRS, the original TWSTRS was examined by a committee of dystonia experts at a dystonia rating scales workshop organized by the Dystonia Medical Research Foundation. During this workshop, deficiencies in the standard TWSTRS were identified and recommendations for revision of the severity and pain subscales were incorporated into the TWSTRS-2. Given that no scale currently evaluates the psychiatric features of cervical dystonia (CD), we used a modified Delphi methodology and a reiterative process of item selection to develop the TWSTRS-PSYCH. We also included the CDIP-58 to capture the impact of CD on quality of life. The three scales (TWSTRS2, TWSTRS-PSYCH, and CDIP-58) were combined to construct the CCDRS. Clinimetric testing of reliability and validity of the CCDRS are described. The CCDRS was designed to be used in a modular fashion that can measure the full spectrum of CD. This scale will provide rigorous assessment for studies of natural history as well as novel symptom-based or disease-modifying therapies.

How long does it take to diagnose cervical dystonia?

BACKGROUND: Dystonia is a neurological disorder characterized by involuntary twisting movements and postures. The neck is among the most commonly affected regions, and diagnosis can be made readily through a simple clinical evaluation. The goal of this study was to explore how long it took patients to receive a diagnosis of cervical dystonia after symptom onset. METHODS: A structured questionnaire was administered at outpatient clinics of a tertiary care academic medical center to 146 consecutively evaluated patients. The questionnaire addressed the length of time from symptom onset to diagnosis, the numbers and types of providers seen before reaching a diagnosis, and treatments attempted prior to receiving botulinum toxin. RESULTS: A total of 108 patients saw a mean of 3.5 providers over a mean period of 44 months from symptom onset to diagnosis. For patients with symptom onset in the last decade only, patients saw a mean of 3.0 providers over a mean of 14 months. CONCLUSIONS: Although cervical dystonia is the most common form of dystonia with clinical features readily identifiable by a simple history and examination, patients typically see multiple providers over more than a year before reaching a diagnosis and receiving optimal therapy. Improved awareness of the clinical features will enable patients to obtain appropriate therapy more rapidly.

The focal dystonias: current views and challenges for future research.

The most common forms of dystonia are those that develop in adults and affect a relatively isolated region of the body. Although these adult-onset focal dystonias are most prevalent, knowledge of their etiologies and pathogenesis has lagged behind some of the rarer generalized dystonias, in which the identification of genetic defects has facilitated both basic and clinical research. This summary provides a brief review of the clinical manifestations of the adult-onset focal dystonias, focusing attention on less well understood clinical manifestations that need further study. It also provides a simple conceptual model for the similarities and differences among the different adult-onset focal dystonias as a rationale for lumping them together as a class of disorders while at the same time splitting them into subtypes. The concluding section outlines some of the most important research questions for the future. Answers to these questions are critical for advancing our understanding of this group of disorders and for developing novel therapeutics.

Paraoxonase-1 polymorphisms in Alzheimer's disease, Parkinson's disease, and AD-PD spectrum diseases.

Paraoxonase-1 (PON1) is a serum arylsulfatase that metabolizes organophosphate pesticides and protects low-density lipoprotein from oxidation. Case-control studies of PON1 genetic variants in Alzheimer's disease (AD) and Parkinson's disease (PD) have revealed some positive albeit inconsistent associations with 2 PON1 coding polymorphisms: Q192R (rs662) and L55M (rs854560). Because AD and PD exist along a spectrum of disorders with shared epidemiologic, clinical, and pathologic features, here we evaluated PON1 variants in a cohort of 746 AD, 566 PD, 132 AD-PD, and 719 cognitively normal age-matched controls. In the combined AD and Caucasian PD cohorts we had 80% power to detect a relative risk of at least 1.25 and 1.35, respectively, for each polymorphism. We found no association between 2 PON1 coding polymorphisms and AD in African Americans or Caucasians, and no association with PD or AD-PD in Caucasians. There was also no evidence of an interaction between PON1 and apolipoprotein E for any of these diseases. Our results suggest that either these functional PON1 polymorphisms are not associated with AD and PD spectrum disorders, or that the relative risk conferred is small.

Disease-related and genetic correlates of psychotic symptoms in Parkinson's disease.

Our aim was to examine disease-related and genetic correlates of the development of psychotic symptoms in a large population of patients with Parkinson's disease. We studied 500 patients with Parkinson's disease from the NeuroGenetics Research Consortium using logistic regression models. Predictors were demographic, clinical (motor/nonmotor features), and genetic, measured as continuous or dichotomous variables. Continuous measures were divided into population-based tertiles. Results are given as odds ratios (95% confidence intervals) for dichotomous variables and by ascending tertile for continuous variables. Psychotic symptoms were associated with increasing age: 4.86 (1.62-14.30) and 6.25 (2.09-18.74) (test for trend: P = 0.01); and duration of disease: 3.81 (1.23-11.76) and 5.33 (1.68-16.89) (test for trend: P = 0.03). For nonmotor features, we demonstrated positive trends with depression: 1.31 (0.47-3.61) and 5.01 (2.04-12.33) (test for trend: P < 0.0001); cognitive dysfunction: 0.69 (0.26-1.84) and 2.51 (1.00-6.29) (test for trend: P = 0.03); and an excess for those with sleep disorders: 2.00 (1.03-3.89) (P = 0.04). Psychotic symptoms were not associated with tremor or postural instability scores, but there was an association with freezing of gait: 3.83 (1.67-8.75) (P < 0.002). Psychotic symptoms were not associated with the presence of any examined polymorphisms in the apolipoprotein, alpha-synuclein, or microtubule associated protein tau genes. This is the largest study to examine correlates of psychotic symptoms in Parkinson's disease. We discovered a novel association with freezing of gait. We demonstrated an association with depression and duration of disease, both of which were inconsistently related in previous studies, and confirmed the association with age, cognitive dysfunction, and sleep disorders.