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Yang Y, Xia C, Zhou Z, Wei D, Xu K, Jia J, Xu W, Zhang H. A multiplex ligation‑dependent probe amplification‑based next‑generation sequencing approach for the detection of copy number variations in the human genome. Mol Med Rep 2018; 18:5823-5833. [PMID: 30365071 DOI: 10.3892/mmr.2018.9581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 09/28/2018] [Indexed: 11/05/2022] Open
Abstract
The aim of the present study was to describe a multiplex ligation‑dependent probe amplification (MLPA)‑based next‑generation sequencing (NGS) assay that exhibited a significantly higher efficiency in detecting copy number variations (CNVs) and known single‑nucleotide variants, compared with traditional MLPA. MLPA polymerase chain reaction products were used to construct a library with indexed adapters, which was subsequently tested on an NGS platform, and the resulting data were analyzed by a series of analytical software. The reads from each probe reflected genetic variations in the target regions, and fragment differentiation was based on the specific base composition of the sequences, rather than fragment length, which was determined by capillary electrophoresis. The results of this approach were not only consistent with the MLPA results following capillary electrophoresis, but also coincided with the CNV results from the single‑nucleotide polymorphism array chip. This method allowed high‑throughput screening for the number of fragments and samples by integrating additional indices for detection. Furthermore, this technology precisely and accurately performed large‑scale detection and quantification of DNA variations, thereby serving as an effective and sensitive method for diagnosing genetic disorders caused by CNVs and known single‑nucleotide variations. Notably, MLPA‑NGS circumvents the problems associated with the inaccuracies of NGS in CNV detection due to the use of target sequence capture.
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Affiliation(s)
- Yongchen Yang
- Department of Laboratory Medicine, Children's Hospital of Shanghai, Shanghai Jiao Tong University, Shanghai 200040, P.R. China
| | - Chaoran Xia
- Shanghai Institute of Medical Genetics, Children's Hospital of Shanghai, Shanghai Jiao Tong University, Shanghai 200040, P.R. China
| | - Zaiwei Zhou
- Product Department, WuXi Health Net Co., Ltd., Shanghai 200131, P.R. China
| | - Dongkai Wei
- BasePair Biotechnology Co., Ltd., Suzhou, Jiangsu 215028, P.R. China
| | - Kangping Xu
- BasePair Biotechnology Co., Ltd., Suzhou, Jiangsu 215028, P.R. China
| | - Jia Jia
- Shanghai Center for Bioinformation Technology, Shanghai Institutes of Biomedicine, Shanghai Academy of Science and Technology, Shanghai 201203, P.R. China
| | - Wuhen Xu
- Department of Laboratory Medicine, Children's Hospital of Shanghai, Shanghai Jiao Tong University, Shanghai 200040, P.R. China
| | - Hong Zhang
- Department of Laboratory Medicine, Children's Hospital of Shanghai, Shanghai Jiao Tong University, Shanghai 200040, P.R. China
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Karadima G, Koutsis G, Karletidi KM, Panas M. Reevaluation of the CMT1A duplication frequency in Greek Charcot-Marie-Tooth type 1 patients. Clin Genet 2014; 86:603. [PMID: 24635740 DOI: 10.1111/cge.12382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/12/2014] [Accepted: 03/13/2014] [Indexed: 11/26/2022]
Affiliation(s)
- G Karadima
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, University of Athens Medical School, Athens, Greece
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Schreiber S, Oldag A, Kornblum C, Kollewe K, Kropf S, Schoenfeld A, Feistner H, Jakubiczka S, Kunz WS, Scherlach C, Tempelmann C, Mawrin C, Dengler R, Schreiber F, Goertler M, Vielhaber S. Sonography of the median nerve in CMT1A, CMT2A, CMTX, and HNPP. Muscle Nerve 2013; 47:385-95. [PMID: 23381770 DOI: 10.1002/mus.23681] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2012] [Indexed: 02/06/2023]
Abstract
INTRODUCTION In this study we compare the ultrasound features in the median nerve in patients with different types of Charcot-Marie-Tooth (CMT) disease and hereditary neuropathies with liability to pressure palsies (HNPP) as a typical entrapment neuropathy. METHODS Median nerve ultrasound and conduction studies were performed in patients with CMT1A (n = 12), MFN2-associated CMT2A (n = 7), CMTX (n = 5), and HNPP (n = 5), and in controls (n = 28). RESULTS Median nerve cross-sectional area (CSA) was significantly increased in CMT1A, whereas, in axonal CMT2A, fascicle diameter (FD) was enlarged. CSA correlated with nerve conduction slowing in CMT1A and with axonal loss, as shown by motor and sensory nerve amplitudes in both CMT1A and CMT2A. A relatively low wrist-to-forearm-ratio (WFR <0.8) or a relatively high WFR (>1.8) appeared to be unlikely in MFN2 and Cx32 mutations of CMT2A and CMTX, respectively. CONCLUSION Differences in CSA, FD, and WFR of the median nerve can be helpful in defining subtypes of hereditary neuropathies.
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Affiliation(s)
- Stefanie Schreiber
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.
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Li X, Zi X, Li L, Zhan Y, Huang S, Li J, Li X, Li X, Hu Z, Xia K, Tang B, Zhang R. Rapid genetic screening of Charcot-Marie-Tooth disease type 1A and hereditary neuropathy with liability to pressure palsies patients. Neural Regen Res 2012; 7:2522-7. [PMID: 25337104 PMCID: PMC4200708 DOI: 10.3969/j.issn.1673-5374.2012.32.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 09/10/2012] [Indexed: 11/18/2022] Open
Abstract
We used the allele-specific PCR-double digestion method on peripheral myelin protein 22 (PMP22) to determine duplication and deletion mutations in the proband and family members of one family with Charcot-Marie-Tooth disease type 1 and one family with hereditary neuropathy with liability to pressure palsies. The proband and one subclinical family member from the Charcot-Marie-Tooth disease type 1 family had a PMP22 gene duplication; one patient from the hereditary neuropathy with liability to pressure palsies family had a PMP22 gene deletion. Electron microscopic analysis of ultrathin sections of the superficial peroneal nerve from the two probands demonstrated demyelination and myelin sheath hyperplasia, as well as an ‘onion-like’ structure in the Charcot-Marie-Tooth disease type 1A patient. We observed an irregular thickened myelin sheath and ‘mouse-nibbled’-like changes in the patient with hereditary neuropathy with liability to pressure palsies. In the Charcot-Marie-Tooth disease type 1A patient, nerve electrophysiological examination revealed moderate-to-severe reductions in the motor and sensory conduction velocities of the bilateral median nerve, ulnar nerve, tibial nerve, and sural nerve. Moreover, the compound muscle action potential amplitude was decreased. In the patient with hereditary neuropathy with liability to pressure palsies, the nerve conduction velocity of the bilateral tibial nerve and sural nerve was moderately reduced, and the nerve conduction velocity of the median nerve and ulnar nerve of both upper extremities was slightly reduced.
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Affiliation(s)
- Xiaobo Li
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Xiaohong Zi
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Lin Li
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Yajing Zhan
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Shunxiang Huang
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Jin Li
- Department of Ultrastructure, School of Basic Medical Science, Central South University, Changsha 410078, Hunan Province, China
| | - Xuning Li
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Xigui Li
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Zhengmao Hu
- State Key Laboratory of Medical Genetics, Central South University, Changsha 410078, Hunan Province, China
| | - Kun Xia
- State Key Laboratory of Medical Genetics, Central South University, Changsha 410078, Hunan Province, China
| | - Beisha Tang
- State Key Laboratory of Medical Genetics, Central South University, Changsha 410078, Hunan Province, China
| | - Ruxu Zhang
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
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Abstract
BACKGROUND Charcot-Marie-Tooth disease (CMT) is the most common inherited disorder of the peripheral nervous system. The frequency of different CMT genotypes has been estimated in clinic populations, but prevalence data from the general population is lacking. Point mutations in the mitofusin 2 (MFN2) gene has been identified exclusively in Charcot-Marie-Tooth disease type 2 (CMT2), and in a single family with intermediate CMT. MFN2 point mutations are probably the most common cause of CMT2. The CMT phenotype caused by mutation in the myelin protein zero (MPZ) gene varies considerably, from early onset and severe forms to late onset and milder forms. The mechanism is not well understood. The myelin protein zero (P(0) ) mediates adhesion in the spiral wraps of the Schwann cell's myelin sheath. X-linked Charcot-Marie Tooth disease (CMTX) is caused by mutations in the connexin32 (cx32) gene that encodes a polypeptide which is arranged in hexameric array and form gap junctions. AIMS Estimate prevalence of CMT. Estimate frequency of Peripheral Myelin Protein 22 (PMP22) duplication and point mutations, insertions and deletions in Cx32, Early growth response 2 (EGR2), MFN2, MPZ, PMP22 and Small integral membrane protein of lysosome/late endosome (SIMPLE) genes. Description of novel mutations in Cx32, MFN2 and MPZ. Description of de novo mutations in MFN2. MATERIAL AND METHODS Our population based genetic epidemiological survey included persons with CMT residing in eastern Akershus County, Norway. The participants were interviewed and examined by one geneticist/neurologist, and classified clinically, neurophysiologically and genetically. Two-hundred and thirty-two consecutive unselected and unrelated CMT families with available DNA from all regions in Norway were included in the MFN2 study. We screened for point mutations in the MFN2 gene. We describe four novel mutations, two in the connexin32 gene and two in the MPZ gene. RESULTS A total of 245 affected from 116 CMT families from the general population of eastern Akershus county were included in the genetic epidemiological survey. In the general population 1 per 1214 persons (95% CI 1062-1366) has CMT. Charcot-Marie-Tooth disease type 1 (CMT1), CMT2 and intermediate CMT were found in 48.2%, 49.4% and 2.4% of the families, respectively. A mutation in the investigated genes was found in 27.2% of the CMT families and in 28.6% of the affected. The prevalence of the PMP22 duplication and mutations in the Cx32, MPZ and MFN2 genes was found in 13.6%, 6.2%, 1.2%, 6.2% of the families, and in 19.6%, 4.8%, 1.1%, 3.2% of the affected, respectively. None of the families had point mutations, insertions or deletions in the EGR2, PMP22 or SIMPLE genes. Four known and three novel mitofusin 2 (MFN2) point mutations in 8 unrelated Norwegian CMT families were identified. The novel point mutations were not found in 100 healthy controls. This corresponds to 3.4% (8/232) of CMT families having point mutations in MFN2. The phenotypes were compatible with CMT1 in two families, CMT2 in four families, intermediate CMT in one family and distal hereditary motor neuronopathy (dHMN) in one family. A point mutation in the MFN2 gene was found in 2.3% of CMT1, 5.5% of CMT2, 12.5% of intermediate CMT and 6.7% of dHMN families. Two novel missense mutations in the MPZ gene were identified. Family 1 had a c.368G>A (Gly123Asp) transition while family 2 and 3 had a c.103G>A (Asp35Asn) transition. The affected in family 1 had early onset and severe symptoms compatible with Dejerine-Sottas syndrome (DSS), while affected in family 2 and 3 had late onset, milder symptoms and axonal neuropathy compatible with CMT2. Two novel connexin32 mutations that cause early onset X-linked CMT were identified. Family 1 had a deletion c.225delG (R75fsX83) which causes a frameshift and premature stop codon at position 247 while family 2 had a c.536G>A (Cys179Tyr) transition which causes a change of the highly conserved cysteine residue, i.e. disruption of at least one of three disulfide bridges. The mean age at onset was in the first decade and the nerve conduction velocities were in the intermediate range. DISCUSSION Charcot-Marie-Tooth disease is the most common inherited neuropathy. At present 47 hereditary neuropathy genes are known, and an examination of all known genes would probably only identify mutations in approximately 50% of those with CMT. Thus, it is likely that at least 30-50 CMT genes are yet to be identified. The identified known and novel point mutations in the MFN2 gene expand the clinical spectrum from CMT2 and intermediate CMT to also include possibly CMT1 and the dHMN phenotypes. Thus, genetic analyses of the MFN2 gene should not be restricted to persons with CMT2. The phenotypic variation caused by different missense mutations in the MPZ gene is likely caused by different conformational changes of the MPZ protein which affects the functional tetramers. Severe changes of the MPZ protein cause dysfunctional tetramers and predominantly uncompacted myelin, i.e. the severe phenotypes congenital hypomyelinating neuropathy and DSS, while milder changes cause the phenotypes CMT1 and CMT2. The two novel mutations in the connexin32 gene are more severe than the majority of previously described mutations possibly due to the severe structural change of the gap junction they encode. CONCLUSION Charcot-Marie-Tooth disease is the most common inherited disorder of the peripheral nervous system with an estimated prevalence of 1 in 1214. CMT1 and CMT2 are equally frequent in the general population. The prevalence of PMP22 duplication and of mutations in Cx32, MPZ and MFN2 is 19.6%, 4.8%, 1.1% and 3.2%, respectively. The ratio of probable de novo mutations in CMT families was estimated to be 22.7%. Genotype- phenotype correlations for seven novel mutations in the genes Cx32 (2), MFN2 (3) and MPZ (2) are described. Two novel phenotypes were ascribed to the MFN2 gene, however further studies are needed to confirm that MFN2 mutations can cause CMT1 and dHMN.
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Affiliation(s)
- G J Braathen
- Head and Neck Research Group, Research Centre, Akershus University Hospital, Lørenskog, Norway.
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Casasnovas C, Banchs I, De Jorge L, Antónia albertí M, Martínez-Campo Y, Povedano M, Montero J, Volpini V. A novel small deletion in PMP22 causes a mild hereditary neuropathy with liability to pressure palsies phenotype. Muscle Nerve 2011; 45:135-8. [DOI: 10.1002/mus.22201] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Al-Khateeb A, Zahri MK, Mohamed MS, Sasongko TH, Ibrahim S, Yusof Z, Zilfalil BA. Analysis of sequence variations in low-density lipoprotein receptor gene among Malaysian patients with familial hypercholesterolemia. BMC MEDICAL GENETICS 2011; 12:40. [PMID: 21418584 PMCID: PMC3071311 DOI: 10.1186/1471-2350-12-40] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 03/19/2011] [Indexed: 11/20/2022]
Abstract
Background Familial hypercholesterolemia is a genetic disorder mainly caused by defects in the low-density lipoprotein receptor gene. Few and limited analyses of familial hypercholesterolemia have been performed in Malaysia, and the underlying mutations therefore remain largely unknown. We studied a group of 154 unrelated FH patients from a northern area of Malaysia (Kelantan). The promoter region and exons 2-15 of the LDLR gene were screened by denaturing high-performance liquid chromatography to detect short deletions and nucleotide substitutions, and by multiplex ligation-dependent probe amplification to detect large rearrangements. Results A total of 29 gene sequence variants were reported in 117(76.0%) of the studied subjects. Eight different mutations (1 large rearrangement, 1 short deletion, 5 missense mutations, and 1 splice site mutation), and 21 variants. Eight gene sequence variants were reported for the first time and they were noticed in familial hypercholesterolemic patients, but not in controls (p.Asp100Asp, p.Asp139His, p.Arg471Gly, c.1705+117 T>G, c.1186+41T>A, 1705+112C>G, Dup exon 12 and p.Trp666ProfsX45). The incidence of the p.Arg471Gly variant was 11%. Patients with pathogenic mutations were younger, had significantly higher incidences of cardiovascular disease, xanthomas, and family history of hyperlipidemia, together with significantly higher total cholesterol and low density lipoprotein levels than patients with non-pathogenic variants. Conclusions Twenty-nine gene sequence variants occurred among FH patients; those with predicted pathogenicity were associated with higher incidences of cardiovascular diseases, tendon xanthomas, and higher total and low density lipoprotein levels compared to the rest. These results provide preliminary information on the mutation spectrum of this gene among patients with FH in Malaysia.
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Affiliation(s)
- Alyaa Al-Khateeb
- Human Genome Centre, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
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Braathen GJ, Sand JC, Lobato A, Høyer H, Russell MB. Genetic epidemiology of Charcot-Marie-Tooth in the general population. Eur J Neurol 2011; 18:39-48. [PMID: 20482598 DOI: 10.1111/j.1468-1331.2010.03037.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE the frequency of different Charcot-Marie-Tooth (CMT) genotypes has been estimated in clinic populations, but prevalence data from the general population are lacking. METHODS our population-based genetic epidemiological survey included persons with CMT residing in eastern Akershus County, Norway. The participants were interviewed and examined by one geneticist/neurologist and classified clinically, neurophysiologically and genetically. RESULTS two hundred and forty-five persons from 116 families had CMT. This corresponds to 1 per 1214 persons (95% CI 1062-1366) have CMT in the general population. CMT1 (motor conduction velocity (MCV) <38 m/s), CMT2 (MCV >38 m/s) and CMT intermediate (MCV 25-45 m/s) were found in 48.2%, 49.4% and 2.4% of the families. A total of 27.2% of the families and 28.6% of the affected had a mutation in the investigated CMT genes. The prevalence of the peripheral myelin protein 22 (PMP22) duplication and point mutation in the connexin32 (Cx32), myelin protein zero (MPZ) and mitofusin2 (MFN2) genes was found in 13.6%, 6.2%, 1.2%, 6.2% of the families, and in 19.6%, 4.8%, 1.1%, 3.2% of the affected, respectively. None of the families had point mutations in the early growth response 2 (EGR2), PMP22 or small integral membrane protein of lysosome/late endosome (SIMPLE) genes. CONCLUSIONS CMT is the most common inherited neuropathy. At present, 43 CMT genes are known, and an examination of all known genes would probably only identify mutations in approximately 50% of those with CMT. Thus, it is probable that at least 30-50 CMT genes are yet to be identified.
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Affiliation(s)
- G J Braathen
- Faculty Division Akershus University Hospital, University of Oslo, Norway.
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