A Large-Scale Full GBA1 Gene Screening in Parkinson's Disease in the Netherlands.

BACKGROUND: The most common genetic risk factor for Parkinson's disease known is a damaging variant in the GBA1 gene. The entire GBA1 gene has rarely been studied in a large cohort from a single population. The objective of this study was to assess the entire GBA1 gene in Parkinson's disease from a single large population. METHODS: The GBA1 gene was assessed in 3402 Dutch Parkinson's disease patients using next-generation sequencing. Frequencies were compared with Dutch controls (n = 655). Family history of Parkinson's disease was compared in carriers and noncarriers. RESULTS: Fifteen percent of patients had a GBA1 nonsynonymous variant (including missense, frameshift, and recombinant alleles), compared with 6.4% of controls (OR, 2.6; P < 0.001). Eighteen novel variants were detected. Variants previously associated with Gaucher's disease were identified in 5.0% of patients compared with 1.5% of controls (OR, 3.4; P < 0.001). The rarely reported complex allele p.D140H + p.E326K appears to likely be a Dutch founder variant, found in 2.4% of patients and 0.9% of controls (OR, 2.7; P = 0.012). The number of first-degree relatives (excluding children) with Parkinson's disease was higher in p.D140H + p.E326K carriers (5.6%, 21 of 376) compared with p.E326K carriers (2.9%, 29 of 1014); OR, 2.0; P = 0.022, suggestive of a dose effect for different GBA1 variants. CONCLUSIONS: Dutch Parkinson's disease patients display one of the largest frequencies of GBA1 variants reported so far, consisting in large part of the mild p.E326K variant and the more severe Dutch p.D140H + p.E326K founder allele. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC. on behalf of International Parkinson and Movement Disorder Society.

Autosomal recessive spinocerebellar ataxia 7 (SCAR7) is caused by variants in TPP1, the gene involved in classic late-infantile neuronal ceroid lipofuscinosis 2 disease (CLN2 disease).

Spinocerebellar ataxias are phenotypically, neuropathologically, and genetically heterogeneous. The locus of autosomal recessive spinocerebellar ataxia type 7 (SCAR7) was previously linked to chromosome band 11p15. We have identified TPP1 as the causative gene for SCAR7 by exome sequencing. A missense and a splice site variant in TPP1, cosegregating with the disease, were found in a previously described SCAR7 family and also in another patient with a SCAR7 phenotype. TPP1, encoding the tripeptidyl-peptidase 1 enzyme, is known as the causative gene for late infantile neuronal ceroid lipofuscinosis disease 2 (CLN2 disease). CLN2 disease is characterized by epilepsy, loss of vision, ataxia, and a rapidly progressive course, leading to early death. SCAR7 patients showed ataxia and low activity of tripeptidyl-peptidase 1, but no ophthalmologic abnormalities or epilepsy. Also, the slowly progressive evolution of the disease until old age and absence of ultra structural curvilinear profiles is different from the known CLN2 phenotypes. Our findings now expand the phenotypes related to TPP1-variants to SCAR7. In spite of the limited sample size and measurements, a putative genotype-phenotype correlation may be drawn: we hypothesize that loss of function variants abolishing TPP1 enzyme activity lead to CLN2 disease, whereas variants that diminish TPP1 enzyme activity lead to SCAR7.

[Risk factors for Parkinson's disease: possibilities for prevention and intervention]. / Risicofactoren voor de ziekte van Parkinson.

Considering age to be the primary risk factor for developing Parkinson's disease and the observation that the Dutch population is rapidly aging, the parkinson prevalence is expected to increase over the coming years, as there is still no cure available for the disease. This has been confirmed by epidemiological data, which show a steady increase of the disease prevalence in the Netherlands for the period 2010-2021. Genetic risk factors only partially explain the disease pathogenesis. Environmental factors, such as exposure to pesticides and trichloroethylene are associated with a higher risk for developing Parkinson's disease. Lifestyle factors such as exercise, caffeine intake and the Mediterranean diet are associated with a lower risk for developing the disease and possibly delay the disease progression. Policy makers and healthcare providers should employ stricter regulations for pesticide use and should stimulate a healthy lifestyle to slow down the increasing prevalence.

Anti-Ri antibody positive opsoclonus-myoclonus in a male patient with breast carcinoma.

A 65-year-old male patient developed truncal ataxia, opsoclonus and myoclonus. In the serum anti-Ri antibodies were found, which led to the detection of a small adenocarcinoma of the breast. Other prominent clinical features were an excessive startle response and behavioral disorders, such as anxiety and impatience. These features suggest an immune response against both Nova-1 and Nova-2 antigens throughout the central nervous system.

A slow orthostatic tremor of primary origin.

BACKGROUND: Orthostatic tremor (OT) is a high-frequency tremor (13-18 Hz) present in the legs when standing. Underlying disease is found in one-third of OT patients. CASE REPORT: We describe an 86-year-old man with progressive shaking of the legs while standing, which disappears immediately after sitting down or while walking. Polymyography confirmed a tremor of the legs (10-11 Hz) while standing. Magnetic resonance imaging (MRI) and neurologic examination showed no underlying disease. DISCUSSION: Primary OT can appear at a lower frequency of 10-11 Hz.

[Collaboration in the first-line setting in medically unexplained symptoms: from powerlessness to coordination]. / Samenwerken rond onverklaarde klachten: van machteloosheid naar regie.

Two women aged 19 and 37 consulted their general practitioners (GPs) for medically unexplained symptoms (MUS). Patient A suffered sudden pain in her legs. She needed crutches, but no somatic explanation could be found. After systematically exploring the history (somatic, emotional and social aspects, thoughts, conduct), the GP initiated a proactive, multidisciplinary treatment regimen. He worked with a mental health nurse practitioner and focused the treatment regimen on the effects of the symptoms. The patient's pain gradually decreased. Patient B had multiple functional complaints. She had little trust in her GP which resulted in inefficient care. The GP explored her history systematically. Together with the nurse practitioner, he initiated a multidisciplinary collaboration and coordinated all the other professionals involved. The patient, now more trusting, visits her GP regularly. Her symptoms still exist.