Barrett, Matthew J.

AbstractINTRODUCTIONMales are disproportionately represented in dementia with Lewy bodies (DLB). Little is known regarding sex differences in cognitive, neuropsychiatric, and motor features of the prodromal stage of DLB.METHODSWe used National Alzheimer's Coordinating Center longitudinal data to examine cognitive, neuropsychiatric, and motor features in 120 males and 23 females 2 years prior to a clinical diagnosis of DLB.RESULTSMales were more likely than females to present with two or more core DLB clinical features 2 years prior to obtaining a diagnosis of dementia. Rapid eye movement sleep behavior disorder, cognitive fluctuations, bradykinesia, and rigidity were more common in males than females. Neuropsychological test performance was similar between groups.DISCUSSIONIn prodromal DLB, males exhibit a greater number of core features than females. Core DLB features may fall short in identifying females at risk. Additional work is needed to better understand the clinical profile of prodromal DLB in females.Highlights There are sex differences in the presentation and course of neurodegenerative disease. Findings from the National Alzheimer's Coordinating Center Uniform Data Set suggest there are sex differences in prodromal DLB symptoms. Females were less likely to demonstrate core clinical features of DLB prior to dementia diagnosis. This information can help inform clinical diagnostic criteria for prodromal DLB.

AbstractBackgroundAs gene‐targeted therapies are increasingly being developed for Parkinson's disease (PD), identifying and characterizing carriers of specific genetic pathogenic variants is imperative. Only a small fraction of the estimated number of subjects with monogenic PD worldwide are currently represented in the literature and availability of clinical data and clinical trial‐ready cohorts is limited.ObjectiveThe objectives are to (1) establish an international cohort of affected and unaffected individuals with PD‐linked variants; (2) provide harmonized and quality‐controlled clinical characterization data for each included individual; and (3) further promote collaboration of researchers in the field of monogenic PD.MethodsWe conducted a worldwide, systematic online survey to collect individual‐level data on individuals with PD‐linked variants in SNCA, LRRK2, VPS35, PRKN, PINK1, DJ‐1, as well as selected pathogenic and risk variants in GBA and corresponding demographic, clinical, and genetic data. All registered cases underwent thorough quality checks, and pathogenicity scoring of the variants and genotype–phenotype relationships were analyzed.ResultsWe collected 3888 variant carriers for our analyses, reported by 92 centers (42 countries) worldwide. Of the included individuals, 3185 had a diagnosis of PD (ie, 1306 LRRK2, 115 SNCA, 23 VPS35, 429 PRKN, 75 PINK1, 13 DJ‐1, and 1224 GBA) and 703 were unaffected (ie, 328 LRRK2, 32 SNCA, 3 VPS35, 1 PRKN, 1 PINK1, and 338 GBA). In total, we identified 269 different pathogenic variants; 1322 individuals in our cohort (34%) were indicated as not previously published.ConclusionsWithin the MJFF Global Genetic PD Study Group, we (1) established the largest international cohort of affected and unaffected individuals carrying PD‐linked variants; (2) provide harmonized and quality‐controlled clinical and genetic data for each included individual; (3) promote collaboration in the field of genetic PD with a view toward clinical and genetic stratification of patients for gene‐targeted clinical trials. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

AbstractBackgroundDementia with Lewy bodies (DLB) is a common neurodegenerative disorder; however, DLB can be difficult to differentiate from Alzheimer’s disease dementia (AD), particularly in the early stages. Research criteria for prodromal DLB were published in 2020 and further studies are needed to validate and refine future clinical criteria.MethodWe analyzed data from the Uniform Data Set from the National Alzheimer’s Coordinating Center (NACC database is funded by NIA/NIH U01‐AG016976). Annual visits occurred across 39 Alzheimer’s Disease Research Centers between September 2005 and September 2021. We identified non‐demented participants [i.e., normal cognition, impaired‐not mild cognitive impairment (MCI) or MCI] at baseline who subsequently received a clinical diagnosis of DLB or AD. Core clinical features (CCF) for DLB (i.e., motor features, visual hallucinations, probable REM sleep behavior disorder (pRBD), cognitive fluctuations), and supportive neuropsychiatric features (NPF; anxiety, apathy, and depression) were assessed through clinical exam and informant responses up to five years prior to dementia diagnosis.ResultThe sample consisted of 160 participants with DLB and 480 age/sex‐matched (1:3) participants with AD at first visit with dementia diagnosis. There was no significant difference in the number of visits prior to dementia diagnosis. The AD group was more racially and ethnically diverse than the DLB group. At the time of diagnosis, DLB participants demonstrated greater functional impairment. Descriptive results indicate CCF and NPF are common in DLB up to five years prior to conversion to dementia; however, motor slowing and NPF were reported in over 20% of the AD participants within the prodromal phase. The presence of 2 or more CCF yielded the greatest AUC (0.786; 95% CI: 0.743, 0.830) in distinguishing DLB from AD one year prior to dementia diagnosis. Combinations of 1 or more CCF with 1, 2, or 3 NPF resulted in significantly lower AUCs (0.725, 0.651, 0.547, respectively) due to decreased specificity.ConclusionCCF and supportive NPF are common in the prodromal phase of DLB; however, parkinsonism and NPF also occurred in the prodromal AD group. Parkinsonism may provide lower discrimination than cognitive fluctuations, visual hallucinations, or pRBD in differentiating DLB from AD in the prodromal phase.

AbstractBackgroundMutations in the parkin gene (PRKN) are the most commonly identified genetic factors in early onset Parkinson disease (EOPD), with biallelic mutations, resulting in a clinical phenotype. However, normal variation is also common in PRKN, particularly in the form of copy number variation (CNV), challenging interpretation of genetic testing results. Here we report a case of a 29‐year‐old male with EOPD and two deletions in PRKN detected by chromosomal microarray (CMA).MethodsThe proband was clinically examined by a neurologist for postural instability with frequent falls, bradykinesia, gait freezing with festination, and hypophonia. Chromosomal microarray analysis (CMA) was performed on the proband and his parents using the Affymetrix CytoScan HD microarray. Subsequent fluorescence in situ hybridization (FISH) was performed on the proband and both parents.ResultsChromosomal microarray detected the presence of two deletions of PRKN in the proband. Parental CMA analysis was performed to determine the clinical significance of this finding, as well as to demonstrate phase of these deletions. Parental CMA revealed that one deletion was paternally inherited and one deletion was de novo. A custom FISH approach was then successfully used to phase the deletions.ConclusionChromosomal microarray and fluorescence in situ hybridization analysis of this trio identified two deletions in PRKN occurring in trans, providing a genetic etiology for the clinical diagnosis of EOPD. The determination of inheritance and phase of the deletions was critical to the proper interpretation of these results. These findings highlight the utility of CMA in the detection of clinically relevant CNVs in cases of EOPD, and also serve to emphasize the importance of follow‐up FISH and parental testing.