Browsing by Author "Chen, Wan-Zi"

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Comprehensive target capture/next-generation sequencing as a second-tier diagnostic approach for congenital muscular dystrophy in Taiwan
(2017-02-09)
Liang, Wen-Chen
;
Tian, Xia
;
Yuo, Chung-Yee
;
Chen, Wan-Zi
;
Kan, Tsu-Min
Purpose Congenital muscular dystrophy (CMD) is a heterogeneous disease entity. The detailed clinical manifestation and causative gene for each subgroup of CMD are quite variable. This study aims to analyze the phenotypes and genotypes of Taiwanese patients with CMD as the epidemiology of CMD varies among populations and has been scantly described in Asia. Methods A total of 48 patients suspected to have CMD were screened and categorized by histochemistry and immunohistochemistry studies. Different genetic analyses, including next-generation sequencing (NGS), were selected, based on the clinical and pathological findings. Results We identified 17 patients with sarcolemma-specific collagen VI deficiency (SSCD), 6 patients with merosin deficiency, two with reduced alpha-dystroglycan staining, and two with striking lymphocyte infiltration in addition to dystrophic change on muscle pathology. Fourteen in 15 patients with SSCD, were shown to have COL6A1, COL6A2 or COL6A3 mutations by NGS analysis; all showed marked distal hyperlaxity and normal intelligence but the overall severity was less than in previously reported patients from other populations. All six patients with merosin deficiency had mutations in LAMA2. They showed relatively uniform phenotype that were compatible with previous studies, except for higher proportion of mental retardation with epilepsy. With reduced alpha-dystroglycan staining, one patient was found to carry mutations in POMT1 while another patient carried mutations in TRAPPC11. LMNA mutations were found in the two patients with inflammatory change on muscle pathology. They were clinically characterized by neck flexion limitation and early joint contracture, but no cardiac problem had developed yet. Conclusion Muscle pathology remains helpful in guiding further molecular analyses by direct sequencing of certain genes or by target capture/NGS as a second-tier diagnostic tool, and is crucial for establishing the genotype-phenotype correlation. We also determined the frequencies of the different types of CMD in our cohort which is important for the development of a specific care system for each disease.
Pediatric necrotizing myopathy associated with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibodies
(2017-02-01)
Liang, Wen-Chen
;
Uruha, Akinori
;
Suzuki, Shigeaki
;
Murakami, Nobuyuki
;
Takeshita, Eri
Objective. Antibodies against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) have recently been associated with immune-mediated necrotizing myopathy, especially in patients with statin exposure. As the data are very limited concerning phenotypes and treatment in paediatric patients, we aimed to identify the paediatric patients positive for anti-HMGCR antibodies and clarify their features and therapeutic strategies. Methods. We screened 62 paediatric patients who were clinically and/or pathologically suspected to have inflammatory myopathy for anti-HMGCR antibodies. We further re-assessed the clinical and histological findings and the treatment of the patients positive for anti-HMGCR antibodies. Results. We identified nine paediatric patients with anti-HMGCR antibodies (15%). This was more frequent than anti-signal recognition particle antibodies (four patients, 6%) in our cohort. The onset age ranged from infancy to 13 years. Five patients were initially diagnosed with muscular dystrophy, including congenital muscular dystrophy. Most patients responded to high-dose corticosteroid therapy first but often needed adjuvant immunosuppressants to become stably controlled. Conclusion. Paediatric necrotizing myopathy associated with anti-HMGCR antibodies may not be very rare. Phenotypes are similar to those of adult patients, but a chronic slowly progressive course may be more frequent. Some patients share the clinicopathological features of muscular dystrophy indicating that recognizing inflammatory aetiology would be challenging without autoantibody information. On the other hand, most patients responded to treatment, especially those who were diagnosed early. Our results suggest the importance of early autoantibody testing in paediatric patients who have manifestations apparently compatible with muscular dystrophy in addition to those who have typical features of inflammatory myopathy.
Probable high prevalence of limb-girdle muscular dystrophy type 2D in Taiwan
(2016-03-15)
Liang, Wen-Chen
;
Chou, Po-Ching
;
Hung, Chia-Cheng
;
Su, Yi-Ning
;
Kan, Tsu-Min
Limb-girdle muscular dystrophy type 2D (LGMD2D), an autosomal-recessive inherited LGMD, is caused by the mutations in SGCA. SGCA encodes alpha-sarcoglycan (SG) that forms a heterotetramer with other SGs in the sarcolemma, and comprises part of the dystrophin-glycoprotein complex. The frequency of LGMD2D is variable among different ethnic backgrounds, and so far only a few patients have been reported in Asia. We identified five patients with a novel homozygous mutation of c.101G>T (p.Arg34Leu) in SGCA from a big aboriginal family ethnically consisting of two tribes in Taiwan. Patient 3 is the maternal uncle of patients 1 and 2. All their parents, heterozygous for c.101G>T, denied consanguineous marriages although they were from the same tribe. The heterozygous parents of patients 4 and 5 were from two different tribes, originally residing in different geographic regions in Taiwan. Haplotype analysis showed that all five patients shared the same mutation-associated haplotype, indicating the probability of a founder effect and consanguinity. The results suggest that the carrier rate of c.101G>T in SGCA may be high in Taiwan, especially in the aboriginal population regardless of the tribes. It is important to investigate the prevalence of LGMD2D in Taiwan for early diagnosis and treatment (C) 2016 Elsevier B.V. All rights reserved.
The natural history of the patients with Duchenne muscular dystrophy in Taiwan: A medical center experience
(2018-04-01)
Liang, Wen-Chen
;
Wang, Chen-Hua
;
Chou, Po-Ching
;
Chen, Wan-Zi
;
Jong, Yuh-Jyh
Background: Duchenne muscular dystrophy (DMD) is the most common hereditary muscular dystrophy and caused by DMD gene mutation. In addition to progressive proximal muscle weakness, respiratory, orthopedic, and gastrointestinal complications are often observed in DMD. The natural history of patients with DMD in Taiwan has not been reported thus far. Methods: Medical records of 39 patients who received a diagnosis of DMD between 1999 and 2016 at Kaohsiung Medical University Hospital were reviewed. The diagnosis of DMD was confirmed through muscle biopsy or DMD genetic analysis. Results: The mean onset age and mean follow-up period were 2.75 years and 6.76 years, respectively. Seventeen patients (43.5%) had a family history of DMD. The mean full intelligence quotient of the patients was 71.08, and the mean age of walking ability loss was 9.7 years (25 patients). The mean onset age of respiratory insufficiency was 10.64 years with a decline rate of 5.18% per year (25 patients). The mean onset age of cardiomyopathy was 14.69 years (seven patients). The mean onset age of scoliosis was 13.29 years with a progression rate of 11.48 degrees per year (14 patients). Eleven (28.2%) and eight (20.5%) patients had deletions and duplications of DMD, respectively. Fourteen patients (35.9%) had point mutations or small deletions or insertions. Five patients received only multiplex ligation-dependent probe amplification (MLPA) analysis and exhibited neither deletion nor duplication. No mutation was identified in one patient through both MLPA and exon sequencing. Conclusion: The clinical phenotypes and disease course in our cohort were consistent with that reported in previous studies. However, the proportion of point mutations or small deletions or insertions in our study was considerably higher than that in reports from other populations. Cardiac ejection fraction was found not a reliable biomarker for identifying cardiac problems, discovering a better parameter is necessary. Copyright (C) 2017, Taiwan Pediatric Association. Published by Elsevier Taiwan LLC.