Sang Jin Kim

Analysis of PARK genes in a Korean cohort of early-onset Parkinson disease

Mutations in five PARK genes (SNCA, PARKIN, DJ-1, PINK1, and LRRK2) are well-established genetic causes of Parkinson disease (PD). Recently, G2385R substitution in LRRK2 has been determined as a susceptibility allele in Asian PD. The objective of this study is to determine the frequency of mutations in these PARK genes in a Korean early-onset Parkinson disease (EOPD) cohort. The authors sequenced 35 exons in SNCA, PARKIN, DJ-1, PINK1, and LRRK2 in 72 unrelated EOPD (age-at-onset ≤50) recruited from ten movement disorders clinics in South Korea. Gene dosage change of the aforementioned genes was studied using multiple ligation-dependent probe amplification. We found four patients with PARKIN mutations, which were homozygous deletion of exon 4, compound heterozygous deletion of exon 2 and exon 4, heterozygous deletion of exon 4, and heterozygous nonsense mutation (Q40X). Four patients had PINK1 mutations; a compound heterozygous mutation (N367S and K520RfsX522) and three heterozygous mutations (G32R, R279H, and F385L). A missense mutation of SNCA (A53T) was found in a familial PD with autosomal dominant inheritance. Nine patients (12.5%) had heterozygous G2385R polymorphism of LRRK2, whereas none had G2019S mutation. However, no mutations were detected in DJ-1 and UCHL1 in our series. We identified genetic variants in PARKIN, PINK1, LRRK2, and SNCA as a cause or genetic risk factors for PD in 25% of Korean EOPD, and mutation of PARKIN was the most common genetic cause.

123 I-Metaiodobenzylguanidine Myocardial Scintigraphy in Lewy Body-Related Disorders: A Literature Review

Lewy body-related disorders are characterized by the presence of Lewy bodies and Lewy neurites, which have abnormal aggregations of α-synuclein in the nigral and extranigral areas, including in the heart. 123I-metaiodobenzylguanidine (MIBG) scintigraphy is a well-known tool to evaluate cardiac sympathetic denervation in the Lewy body-related disorders. MIBG scintigraphy showed low uptake of MIBG in the Lewy body-related disorders, including Parkinson’s disease, dementia with Lewy bodies, pure autonomic failure and rapid eye movement sleep behavior disorder. This review summarizes previous results on the diagnostic applications of MIBG scintigraphy in Lewy body-related disorders.

Mutations at codons 178, 200-129, and 232 contributed to the inherited prion diseases in Korean patients

BackgroundPolymorphisms of the human prion protein gene (PRNP) contribute to the genetic determinants of Creutzfeldt-Jakob disease (CJD). Numerous polymorphisms in the promoter regions as well as the open reading frame of PRNP were investigated. Greater than 90% of Korean, Chinese, and Japanese carry the homozygote 129 MM codon. In Korea, polymorphisms have not been comprehensively studied, except codons 129 and 219 in PRNP among Korean CJD cases. Although polymorphisms at codons 129 and 219 play an important role in susceptibility to sporadic CJD, patients with other polymorphisms in PRNP exhibited critical distinctions of clinical symptoms.MethodsThe genetic analyses of PRNP were carried out among probable CJD patients in comparison with the results from magnetic resonance imaging (MRI) and electroencephalogram (EEG).ResultsThe molecular analyses revealed that three mutations at codons D178N, E200K, and M232R in heterozygosity. Patients with the D178N and M232R mutations had a 129MM codon, whereas the patient with the E200K mutation showed 129MV heterozygosity. They all revealed strong 14-3-3 positive signals. The 67-year-old patient with the D178N-129M mutation showed progressive gait disturbance and dysarthria was in progress. The 58-year-old patient with the E200K mutation coupled to the 129MV codon had gait disturbance, dysarthria, agitation, and ataxic gait, and progressed rapidly to death 3 months from the first onset of symptoms. The 65-year-old patient with the M232R mutation showed rapidly progressive memory decline and gait disturbance, and died within 16 months after onset of symptoms.ConclusionDespite differences in ethnicity, the clinical and pathological outcomes were similar to the respective mutations around the world, except absence of insomnia in D178N-129M subject.

Analysis among cognitive profiles and gray matter volume in newly diagnosed Parkinson's disease with mild cognitive impairment

PURPOSE To analyze the characteristics of neuropsychological profiles and gray matter volume in de novo, drug-naïve Parkinsons disease with mild cognitive impairment (PD-MCI). METHODS Fifty-two newly diagnosed PD patients were assessed with neuropsychological testing, and PD-MCI was defined in patients with at least one or more abnormal cognitive test domains. PD with normal cognition (PD-NC) did not meet the criteria for PD-MCI or PD with dementia. Brain MRI scans was acquired from the patients and healthy controls (HC). The imaging processing and analysis of the gray matter (GM) volume were performed platform to determine the difference between PD-MCI and PD-NC. RESULTS There were no differences of motor subscores between PD-MCI and PD-NC. The clinical dementia rating, global deterioration scale, and verbal memory were significantly worse in PD-MCI than in PD-NC. GM volume loss was observed in the right hippocampus, right cuneus, and right precuneus in PD-NC compared to in the HC. PD-MCI had significantly decreased GM volume in the bilateral temporal and frontal areas compared with that of the HC. The GM volume was significantly decreased in the right temporal pole, left precuneus, medial frontal and posterior cingulated gyrus in PD-MCI compared with PD-NC. CONCLUSIONS Clinical dementia ratings and global deterioration scales could differentiate PD-MCI from PD-NC. Verbal memory impairment is characterized as a cognitive deficit of de novo PD-MCI and is associated with the posterior cortical area.

Differences in myocardial sympathetic degeneration and the clinical features of the subtypes of Parkinson's disease

Parkinsons disease (PD) can be divided into the akinetic-rigid (ART), mixed (MT), and tremor-dominant (TDT) subtypes according to the clinically dominant symptoms. We analyzed the correlations between (123)I-meta-iodobenzylguanidine (MIBG) uptake and the clinical features of patients with various PD subtypes. In addition, we evaluated the relationship between MIBG uptake and the severity of the cardinal motor symptoms among patients with PD subtypes. The mean Unified Parkinsons Disease Rating Scale motor scores differed significantly among patients with different PD subtypes (± standard deviation [SD]) (ART, 34.6 ± 18.28; MT, 24.63 ± 7.78; TDT, 16.22 ± 4.15, p=0.002), especially between the ART and TDT subtypes (p=0.022). The mean MIBG uptake (± SD) was decreased in the TDT (1.69 ± 0.39), MT (1.35 ± 0.32), and ART (1.35 ± 0.22) subtypes (p=0.049). The MIBG uptake values differed significantly between the ART and TDT subtypes (p=0.02). The MIBG uptake was inversely correlated with the severity of hypokinesia in the ART subtype (r=-0.75; p=0.01) and the MT subtype (r=-0.8; p=0.02), but it was not correlated with the severity of any of the parkinsonian motor symptoms in the TDT subtype. These results imply that hypokinesia is strongly associated with sympathetic myocardial degeneration and that sympathetic myocardial degeneration can reflect the progression of the disease in patients with the ART and mixed MT subtypes of PD.

Erratum: Mutation Analysis of SPAST, ATL1, and REEP1 in Korean Patients with Hereditary Spastic Paraplegia

aDepartment of Neurology, Pusan National University School of Medicine, Yangsan, Korea bResearch Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea cDepartment of Neurology, Chonnam National University Hospital, Gwangju, Korea dDepartment of Neurology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea J Clin Neurol 2014;10(3):257-261 http://dx.doi.org/10.3988/jcn.2014.10.3.257 Print ISSN 1738-6586 / On-line ISSN 2005-5013 http://dx.doi.org/10.3988/jcn.2014.10.4.376 ERRATUM J Clin Neurol 2014;10(4):376-376

Usefulness of Diffusion-Weighted MRI for Differentiation between Parkinson’s Disease and Parkinson Variant of Multiple System Atrophy

Background and Purpose: Several studies have reported that diffusion-weighted imaging (DWI) is able to help discriminate a Parkinson variant of multiple system atrophy (MSA-p) from Parkinson’s disease (PD) on the basis of the increased regional apparent diffusion coefficient (rADC). We analyzed the usefulness of DWI by using the rADC for differential diagnosis between MSA-p and PD and investigated the correlation between the rADC value and clinical features of MSA-p and PD. Methods: Twelve patients with PD and 10 with MSA-p were studied. The rADC value was determined in different brain regions, including the dorsal putamen (DP) and middle cerebellar peduncles (MCP). Results: The rADC values of the DP showed a greater increase in MSA-p patients than in PD patients (p=0.03). MSA-p patients also presented increased rADC values of the MCP compared with PD patients (p=0.0001). In particular, the sensitivity, specificity and positive predictive values of the MCP rADC were higher than those of the DP rADC. However, DP and MCP rADC values were not correlated with clinical features in either MSA or PD patients. Conclusions: DWI discriminated between PD and MSA-p based on rADC values in DP and MCP. The MCP rADC value, in particular, could better discriminate MSA-p from PD.

JSAP1 Interacts with Kinesin Light Chain 1 through Conserved Binding Segments

A conventional kinesin, KIF5/kinesin-I, is composed of two kinesin heavy chains (KHCs) and two kinesin light chains (KLCs) and binds directly to microtubules. KIF5 motor mediates the transport of various membranous organelles, but the mechanism how they recognize and bind to a specific cargo has not yet been completely elucidated. Here, we used the yeast two-hybrid system to identify the neuronal protein(s) that interacts with the tetratricopeptide repeats (TRP) of KLC1 and found a specific interaction with JNK/stress-activated protein kinase-associated protein 1 (JSAP1/JIP3). The yeast two-hybrid assay demonstrated that the TRP 1, 2 domain-containing region of KLC1 mediated binding to the leucine zipper domain of JSAP1. JSAP1 also bound to the TRP region of KLC2 but not to neuronal KIF5A, KIF5C and ubiquitous KIF5B in the yeast two-hybrid assay. In addition, these proteins showed specific interactions in the GST pull-down assay and by co-immunoprecipitation. KLC1 and KIF5B interacted with GST-JSAP1 fusion proteins, but not with GST alone. An antibody to JSAP1 specifically co-immunoprecipitated KIF5s associated with JSAP1 from mouse brain extracts. These results suggest that JSAP1, as KLC1 receptor, is involved in the KIF5 mediated transport.

Current Status of Huntington's Disease in Korea: A Nationwide Survey and National Registry Analysis.

Objective Huntington’s disease (HD) is a rare neurological disorder, and its current status in Korea is not well investigated. This study aims to determine the prevalence and incidence of HD and to investigate the clinical features of HD patients in Korea. Methods We estimated the crude prevalence and annual incidence of HD based on the databases of the Rare Diseases Registry (RDR) and the National Health Insurance (NHI). The clinical data of genetically confirmed HD patients was collected from 10 referral hospitals and analyzed. Results The mean calculated annual incidence was 0.06 cases per 100,000 persons, and the mean calculated prevalence was 0.38 based on the NHI database. The estimated crude prevalence based on the RDR was 0.41. Of the sixty-eight HD patients recruited, the mean age of onset was 44.16 ± 14.08 years and chorea was most frequently reported as the initial symptom and chief complaint. The mean CAG repeat number of the expanded allele was 44.7 ± 4.8 and correlated inversely with the age of onset (p < 0.001). About two-thirds of the patients have a positive family history, and HD patients without positive family history showed a delay in onset of initial symptoms, a prolonged interval between initial symptom onset and genetic diagnosis and a delay in the age of genetic diagnosis. Conclusions To the best of our knowledge, this is the first study to estimate the prevalence and incidence of HD in Korea and the largest HD series in the Asian population. Our analyses might be useful for further studies and large-scale investigations in HD patients.

Expansion of the clinicopathological and mutational spectrum of Perry syndrome

BACKGROUND Perry syndrome (PS) caused by DCTN1 gene mutation is clinically characterized by autosomal dominant parkinsonism, depression, severe weight loss, and hypoventilation. Previous pathological studies have reported relative sparing of the cerebral cortex in this syndrome. Here, we characterize novel clinical and neuroimaging features in 3 patients with PS. METHODS (18)F-fluorinated N-3-fluoropropyl-2-ß-carboxymethoxy-3-β-(4-iodophenyl) nortropane ([(18)F]FP-CIT) PET, [(18)F]fluorodeoxyglucose PET, or volumetric MRI was performed in probands, and imaging data were analyzed and compared with those of control subjects. RESULTS We identified 2 novel mutations of DCTN1. Oculogyric crisis that presented before levodopa treatment was observed in 1 case. One patient had supranuclear gaze palsy. In 2 cases, [(18)F]FP-CIT showed marked loss of dopamine transporter binding with only mild parkinsonism. Areas of hypometabolism or cortical thickness change were observed in dorsolateral frontal, anterior cingulate, lateral temporal, and inferior parietal cortices. CONCLUSION Oculomotor manifestations are not uncommon in PS. Neuroimaging studies suggest involvement of the frontotemporoparietal cortex, which may be the clinical correlate of apathy and depression, as well as pathological changes in subcortical structures.