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Kim SH, Seo J, Kwon SS, Teng LY, Won D, Shin S, Lee JS, Lee ST, Choi JR, Kang HC. Common genes and recurrent causative variants in 957 Asian patients with pediatric epilepsy. Epilepsia 2024; 65:766-778. [PMID: 38073125 DOI: 10.1111/epi.17857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE We aimed to identify common genes and recurrent causative variants in a large group of Asian patients with different epilepsy syndromes and subgroups. METHODS Patients with unexplained pediatric-onset epilepsy were identified from the in-house Severance Neurodevelopmental Disorders and Epilepsy Database. All patients underwent either exome sequencing or multigene panels from January 2017 to December 2019, at Severance Children's Hospital in Korea. Clinical data were extracted from the medical records. RESULTS Of the 957 patients studied, 947 (99.0%) were Korean and 570 were male (59.6%). The median age at testing was 4.91 years (interquartile range, 1.53-9.39). The overall diagnostic yield was 32.4% (310/957). Clinical exome sequencing yielded a diagnostic rate of 36.9% (134/363), whereas the epilepsy panel yielded a diagnostic rate of 29.9% (170/569). Diagnostic yield differed across epilepsy syndromes. It was high in Dravet syndrome (87.2%, 41/47) and early infantile developmental epileptic encephalopathy (60.7%, 17/28), but low in West syndrome (21.8%, 34/156) and myoclonic-atonic epilepsy (4.8%, 1/21). The most frequently implicated genes were SCN1A (n = 49), STXBP1 (n = 15), SCN2A (n = 14), KCNQ2 (n = 13), CDKL5 (n = 11), CHD2 (n = 9), SLC2A1 (n = 9), PCDH19 (n = 8), MECP2 (n = 6), SCN8A (n = 6), and PRRT2 (n = 5). The recurrent genetic abnormalities included 15q11.2 deletion/duplication (n = 9), Xq28 duplication (n = 5), PRRT2 deletion (n = 4), MECP2 duplication (n = 3), SCN1A, c.2556+3A>T (n = 3), and 2q24.3 deletion (n = 3). SIGNIFICANCE Here we present the results of a large-scale study conducted in East Asia, where we identified several common genes and recurrent variants that varied depending on specific epilepsy syndromes. The overall genetic landscape of the Asian population aligns with findings from other populations of varying ethnicities.
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Affiliation(s)
- Se Hee Kim
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
- Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, South Korea
| | - Jieun Seo
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Soon Sung Kwon
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Lip-Yuen Teng
- Pediatric Neurology Unit, Department of Pediatrics, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
| | - DongJu Won
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Joon Soo Lee
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
- Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, South Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
- Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, South Korea
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Kim J, Teng LY, Shaker B, Na D, Koh HY, Kwon SS, Lee JS, Kim HD, Kang HC, Kim SH. Genotypes and phenotypes of DNM1 encephalopathy. J Med Genet 2023; 60:1076-1083. [PMID: 37248033 DOI: 10.1136/jmg-2023-109233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 04/30/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND Variants in the dynamin-1 (DNM1) gene typically cause synaptopathy, leading to developmental and epileptic encephalopathy (DEE). We aimed to determine the genotypic and phenotypic spectrum of DNM1 encephalopathy beyond DEE. METHODS Electroclinical phenotyping and genotyping of patients with a DNM1 variant were conducted for patients undergoing next-generation sequencing at our centre, followed by a systematic review. RESULTS Six patients with heterozygous DNM1 variants were identified in our cohort. Three had a typical DEE phenotype characterised by epileptic spasms, tonic seizures and severe-to-profound intellectual disability with pathogenic variants located in the GTPase or middle domain. The other three patients had atypical phenotypes of milder cognitive impairment and focal epilepsy. Genotypically, two patients with atypical phenotypes had variants located in the GTPase domain, while the third patient had a novel variant (p.M648R) in the linker region between pleckstrin homology and GTPase effector domains. The third patient with an atypical phenotype showed normal development until he developed febrile status epilepticus. Our systematic review on 55 reported cases revealed that those with GTPase or middle domain variants had more severe intellectual disability (p<0.001) and lower functional levels of ambulation (p=0.001) or speech and language (p<0.001) than the rest. CONCLUSION DNM1-related phenotypes encompass a wide spectrum of epilepsy and neurodevelopmental disorders, with specific variants underlying different phenotypes.
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Affiliation(s)
- Jeehyun Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
| | - Lip-Yuen Teng
- Paediatric Neurology, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
| | - Bilal Shaker
- Department of Biomedical Engineering, Chung-Ang University, Seoul, Korea
| | - Dokyun Na
- Department of Biomedical Engineering, Chung-Ang University, Seoul, Korea
| | - Hyun Yong Koh
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Soon Sung Kwon
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seodaemun-gu, Korea
| | - Joon Soo Lee
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
- Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Seoul, Korea
- Epilepsy Research Institute, Yonsei University College of Medicine, Epilepsy Research Institute, Seoul, Korea
| | - Heung Dong Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
- Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Seoul, Korea
- Epilepsy Research Institute, Yonsei University College of Medicine, Epilepsy Research Institute, Seoul, Korea
| | - Hoon-Chul Kang
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
- Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Seoul, Korea
- Epilepsy Research Institute, Yonsei University College of Medicine, Epilepsy Research Institute, Seoul, Korea
| | - Se Hee Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
- Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Seoul, Korea
- Epilepsy Research Institute, Yonsei University College of Medicine, Epilepsy Research Institute, Seoul, Korea
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Teng LY, Abd Hadi D, Anandakrishnan P, Murugesu S, Khoo TB, Mohamed AR. Geniospasm: A systematic review on natural history, prognosis, and treatment. Brain Dev 2022; 44:499-511. [PMID: 35672188 DOI: 10.1016/j.braindev.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/07/2022] [Accepted: 05/23/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Geniospasm is a rare and generally benign movement disorder of the chin yet with potentially debilitating complications. Due to its rarity, previous literature was limited to only case reports or series with critical knowledge gap on its natural history, prognosis, and management. We aimed to establish the natural history, prognosis, and treatment for geniospasm. METHODS A systematic review on case reports or series was performed with literature search on PubMed and Google Scholar, from inception through December 2021. The quality of the reports was assessed with low-quality articles excluded for analyses other than demographics. RESULTS Forty-one articles were included for demographic analysis (n = 489) while forty articles for other analyses (n = 451). There was only slight male preponderance of this disease in our cohort (Male:Female = 1.2:1) with 98.6% having family history of geniospasm, 68.1% having onset below 1 year of age, 91.4% having emotional triggers of the symptoms, 25.7% having geniospasm in sleep, 100% involving mentalis muscles, 4.9% involving muscles adjacent to mentalis, 55.2% having regular paroxysms (≥1/week, but brief in 56.3% of the cases) and only 11.1% having complications. The paroxysms reduced with age, but complete remission only happened in 9.9%. Females (p = 0.010) and those without geniospasm in sleep (p = 0.048) were associated with good outcome of the disease. Geniospasm was usually refractory to treatment except for regular botulinum toxin injections. CONCLUSION Generally, geniospasm improved with age but complete remission was rare. Considering our review limitations, our findings should be interpreted with caution. Future studies of higher evidence level are crucial.
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Affiliation(s)
- Lip-Yuen Teng
- Paediatric Neurology Unit, Department of Paediatrics, Hospital Tunku Azizah, Kuala Lumpur, Malaysia.
| | - Dianah Abd Hadi
- Paediatric Neurology Unit, Department of Paediatrics, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
| | - Poorani Anandakrishnan
- Paediatric Neurology Unit, Department of Paediatrics, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
| | - Sumitha Murugesu
- Paediatric Neurology Unit, Department of Paediatrics, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
| | - Teik-Beng Khoo
- Paediatric Neurology Unit, Department of Paediatrics, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
| | - Ahmad Rithauddin Mohamed
- Paediatric Neurology Unit, Department of Paediatrics, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
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Harba MI, Teng LY. Reliability of measurement of muscle fiber conduction velocity using surface EMG. Front Med Biol Eng 1999; 9:31-47. [PMID: 10354908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Cross-correlating two surface EMG signals detected at two different locations along the path of flow of action potential enables the measurement of the muscle fiber average conduction velocity in those active motor units monitored by the electrodes. The position of the peak of the cross-correlation function is the time delay between the two signals and hence the velocity may be deduced. The estimated velocity using this technique has been observed previously to depend on the location of the electrodes on the muscle surface. Different locations produced different estimates. In this paper we present a measurement system, analyze its inherent inaccuracies and use it for the purpose of investigating the reliability of measurement of conduction velocity from surface EMG. This system utilizes EMG signals detected at a number of locations on the biceps brachii, when under light tension, to look for any pattern of variations of velocity as a function of location and time. It consists of a multi-electrode unit and a set of eight parallel on-line correlators. The electrode unit and the parallel correlators ensure that these measurements are carried out under the same physical and physiological conditions of the muscle. Further, the same detected signals are used in different measurement configurations to try to understand the reasons behind the observed variations in the estimated velocity. The results obtained seem to suggest that there will always be an unpredictable random component superimposed on the estimated velocity, giving rise to differences between estimates at different locations and differences in estimates with time at the same location. Many factors contribute to this random component, such as the non-homogeneous medium between the muscle fibers and the electrodes, the non-parallel geometry and non-uniform conduction velocity of the fibers, and the physical and physiological conditions of the muscle. While it is not possible to remove this random component completely from the measurement, the user must be aware of its presence and how to reduce its effects.
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Affiliation(s)
- M I Harba
- Universiti Sains Malaysia, Perak, Malaysia
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Lee HS, Gwee KA, Teng LY, Kang JY, Yeoh KG, Wee A, Chua BC. Validation of [13C]urea breath test for Helicobacter pylori using a simple gas chromatograph-mass selective detector. Eur J Gastroenterol Hepatol 1998; 10:569-72. [PMID: 9855080 DOI: 10.1097/00042737-199807000-00008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVE Isotope ratio mass spectrometry (IRMS) is the accepted method for accurately measuring the 13CO2:12CO2 ratio in the non-invasive and non-radioactive [13C]urea breath test (13C-UBT) for Helicobactor pylori. The IRMS instrument, an expensive and highly specialized analyser, is rarely available. The objective of this project was to modify and validate the use of a simple bench-top gas chromatograph-mass selective detector (GC-MSD) for 13C-UBT. METHODS Breath samples from 71 patients were taken at baseline and 30 min after ingestion of 100 mg [13C]urea. The breath samples were analysed using GC-MSD in the selected ion monitoring mode. The reference 13CO2:12CO2 ratio was from NBS19 obtained from the US National Institute of Standards and Technology. 13CO2:12CO2 ratios of the breath samples were determined. Excess delta per thousand (per mil, delta/thousand) of the 30 min sample over the baseline (deltadelta/thousand) of > or = 6deltadelta/thousand was considered H. pylori positive. Results from 13C-UBT and histology determined blind to each other were compared. RESULTS The coefficient of variation of the reference 13CO2:12CO2 ratio was 0.06%. Using histology as the 'gold standard', the sensitivity (97.9%) and specificity (95.8%) of the GC-MSD 13C-UBT were comparable to those of other methods of H. pylori diagnosis. CONCLUSION A gas chromatograph coupled to a mass selective detector that is available in many analytical and biomedical laboratories can be used for the 13C-UBT. This method will increase the availability and reduce the cost of this non-invasive, non-radioactive diagnostic test.
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Affiliation(s)
- H S Lee
- Department of Pharmacology, National University of Singapore, Singapore.
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Mazumdar J, Banerjee M, Teng LY. A mathematical study of simple exponential modelling in biochemical processes. Australas Phys Eng Sci Med 1991; 14:226-33. [PMID: 1789775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This paper discusses the application of simple exponential functions for analyses of complex biochemical processes such as transport phenomena in a mammalian system. The main aim is to identify these exponential function models using various curve fitting techniques. The experimental data used is based on transport of a radio-active tracer 32P (Radio-phosphorus) from a central compartment of blood plasma to subsidiary organ compartments in insulin-treated diabetic rats. The data has been analysed with a view to fitting exponential functions. A graphical method of exponential peeling and six (I to VI) computer programs based on iterative methods for solving single, as well as, multiple exponential functions have been used. The method of exponential peeling has also been compared with the least squares method for simple linear regression. The sum of two exponential functions has been found to be the most preferred Goodness of Fit by the computer programs. This model indicates that the transport of 32P in blood plasma in rats is governed by two major metabolic parameters. Further interpretations of the fitted equations are discussed.
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Affiliation(s)
- J Mazumdar
- Department of Applied Mathematics, University of Adelaide, South Australia
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