Lysosomal dysfunction plays an important role in neurodegenerative diseases, including Parkinson’s disease (PD) and possibly Parkinson-plus syndromes such as progressive supranuclear palsy (PSP). This role is exemplified by the involvement of variants in the GBA1 gene, which results in a deficiency of the lysosomal enzyme glucocerebrosidase and is the most frequently identified genetic factor underlying PD worldwide. Pathogenic variants in the SMPD1 gene are a recessive cause of Niemann–Pick disease types A and B. Here, we provide the first report on an association between a loss-of-function variant in the SMPD1 gene present in a heterozygous state (p.Pro332Arg/p.P332R, which is known to result in reduced lysosomal acid sphingomyelinase activity), with PSP-Richardson syndrome in three unrelated patients of Chinese ancestry.

KMT2B-linked dystonia (DYT-KMT2B) is a childhood-onset dystonia syndrome typically beginning in the lower limbs and progressing caudocranially to affect the upper limbs with eventual prominent craniocervical involvement. Despite its recent recognition, it now appears to be one of the more common monogenic causes of dystonia syndromes. Here, we present an atypical case of DYT-KMT2B with oromandibular dystonia as the presenting feature, which remained restricted to this region three decades after symptom onset. This appears to be the first reported case of DYT-KMT2B from Southeast Asia and provides further supporting evidence for the pathogenic impact of the KMT2B c.6210_6213delTGAG variant.

Background: Mutations in glucocerebrosidase (GBA) have been associated with the risk of developing Parkinson’s disease (PD) in different ethnic populations. The prevalence of GBA mutations among Malay PD patients is unknown. Thus, the aim of this study was to determine the frequency of GBA mutations among Malay PD patients, focusing on early (EOPD) and late-onset (LOPD) patients. Methods:EOPD (n = 50) and LOPD (n = 50) patients along with 50 ethnically and age-matched control wererecruited. The GBA exons of these patients were sequenced using the Ion Torrent PGMTM System. Results: Five heterozygous mutations exclusive to EOPD patients were identified; c.-203A>G,p.S146L, p.R159Q, p.L483P and p.L483R+c.-145G>A. In LOPD patients, c.543C>T(p.(F181=)), c.28-10C>A and p.R202Q were identified in which this p.R202Q was also present in a control subject. In addition, c.259C>A(p.(R87=)) and c.-145G>A were identified in two control subjects. In summary, we observed GBA mutations in 8% and 6% of Malay PD cases and control subject, respectively. The prevalence of GBA mutations was higher in EOPD (10%) than LOPD (6%). However, these differences were not statistically significant; [PD vs. controls: OR = 1.36, 95%CI 0.35-5.38, p = 0.752] and [EOPD vs. LOPD: OR = 1.74, 95%CI 0.39-7.71, p = 0.715]. Conclusion: We identified five exclusive heterozygous GBA mutations in EOPD patients which might predict the increase susceptibility of Malays to develop PD at young age. These findings could add knowledge into the existing evidences linking genetic alterations in GBA and PD.

No abstract available.
Diffusion Tensor Imaging ; Diffusion ; Hemiplegia ; Humans

We present a case of beta-propeller protein-associated neurodegeneration, a form of neurodegeneration with brain iron accumulation. The patient harbored a novel mutation in the WDR45 gene. A detailed video and description of her clinical condition are provided. Her movement disorder phenomenology was characterized primarily by limb stereotypies and gait dyspraxia. The patient's disability was advanced by the time iron-chelating therapy with deferiprone was initiated, and no clinical response in terms of cognitive function, behavior, speech, or movements were observed after one year of treatment.
Brain ; Chelation Therapy ; Cognition ; Extremities ; Gait Apraxia ; Humans ; Iron ; Movement Disorders

Purposeless groaning has been reported in advanced progressive supranuclear palsy. We present a case of purposeless groaning occurring as a primary complaint in a patient with advanced Parkinson's disease. Purposeless groaning is thought to be a manifestation of disinhibition and perseveration due to frontal-subcortical dysfunction. Proper recognition of this phenomenon will help clinicians to avoid unnecessary investigations and treatment (e.g., prescription of opioid medications).
Humans ; Parkinson Disease ; Prescriptions ; Supranuclear Palsy, Progressive

Mitochondrial DNA (mtDNA) deletions are a major cause of chronic progressive external ophthalmoplegia (CPEO) and Kearns-Sayre syndrome (KSS). We analyzed single mtDNA deletions in 11 CPEO and one KSS patients by means of Southern blot and long polymerase chain reaction (PCR) assays. The deletion sizes ranged from 3.4 kb to 6.9 kb whereas the heteroplasmy level varied from 18.8% to 85.5%. Two unique deletions sized 4320 bp and 4717 bp were found. This study represents the first genetic screen of mtDNA disorders in Malaysia, and it follows the data seen in other published reports on CPEO and KSS genetic aetiology.

INTRODUCTIONThe G2385R and R1628P LRRK2 gene variants have been associated with an increased risk of Parkinson's disease (PD) in the Asian population. Recently, a new LRRK2 gene variant, A419V, was reported to be a third risk variant for PD in Asian patients. Our objective was to investigate this finding in our cohort of Asian subjects.

MATERIALS AND METHODSEight hundred and twenty-eight subjects (404 PD patients, and 424 age and gender-matched control subjects without neurological disorders) were recruited. Genotyping was done by Taqman® allelic discrimination assay on an Applied Biosystems 7500 Fast Real-Time PCR machine.

RESULTSThe heterozygous A419V genotype was found in only 1 patient with PD, compared to 3 in the control group (0.4% vs 1.3%), giving an odds ratio of 0.35 (95% confidence interval (CI), 0.01 to 3.79; P = 0.624).

CONCLUSIONA419V is not an important LRRK2 risk variant in our Asian cohort of patients with PD. Our data are further supported by a literature review which showed that 4 out of 6 published studies reported a negative association of this variant in PD.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Alanine ; genetics ; Case-Control Studies ; China ; ethnology ; Cohort Studies ; Cytosine ; Female ; Gene Frequency ; Genetic Variation ; genetics ; Genotype ; Heterozygote ; Humans ; India ; ethnology ; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 ; Malaysia ; ethnology ; Male ; Middle Aged ; Parkinson Disease ; genetics ; Polymorphism, Genetic ; genetics ; Protein-Serine-Threonine Kinases ; genetics ; Risk Factors ; Singapore ; Thymine ; Valine ; genetics ; Young Adult

A cohort of Malaysian patients with clinico-pathological diagnosis of three specifi c mitochondrial encephalomyopathy syndromes comprising of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), myoclonus epilepsy with ragged-red fi bers (MERRF) and Leigh syndrome were studied to determine the frequency of their common mitochondrial DNA mutations. The ‘hot-spot’ point mutations for MELAS, MERRF and Leigh syndrome were screened. In the absence of common point mutations, screening of large-scale deletions as well as sequencing of tRNALeu and tRNALys genes were performed. Of 22 patients studied, nine m.3243A>G mutations, four m.8344A>G mutations, one m.8993T>G mutation and one deletion were identifi ed (65% detection rate). While the m.3243A>G mutation was closely associated with MELAS, the m.8344A>G was more heterogenous, being seen in one MERFF, two isolated mitochondrial myopathies and one Leigh syndrome patient. Screening for m.8993T>G in Leigh syndrome has a low yield as unsurprisingly Leigh syndrome has considerable genetic heterogeneity.