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Mercuri E, Cini C, Pichiecchio A, Allsop J, Counsell S, Zolkipli Z, Messina S, Kinali M, Brown SC, Jimenez C, Brockington M, Yuva Y, Sewry CA, Muntoni F. Muscle magnetic resonance imaging in patients with congenital muscular dystrophy and Ullrich phenotype. Neuromuscul Disord 2003; 13:554-8. [PMID: 12921792 DOI: 10.1016/s0960-8966(03)00091-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The aim of this study was to evaluate muscle magnetic resonance imaging findings in patients with congenital muscular dystrophy and Ullrich phenotype. Fifteen children with congenital muscular dystrophy and Ullrich phenotype were included in the study. All patients had collagen VI studies in muscle and, when family structure was informative, linkage studies to the collagen 6 loci. Three of the 15 patients had reduced collagen in muscle. One of the three was from an informative family and linked to one of the collagen 6 loci. Another patient was linked to one of the collagen 6 loci but had normal expression of collagen in muscle. The remaining 11 all had normal collagen expression in muscle. Only two of these 11 were from informative families and linkage to collagen 6 loci was excluded in them. All patients had muscle magnetic resonance imaging of their leg muscles using transverse T1 sequences. With the exception of the two patients in whom linkage to the collagen 6 loci was excluded, the other 13 patients showed the same pattern of selective involvement on magnetic resonance imaging of thigh muscles. This consisted of relative sparing of sartorius, gracilis, adductor longus and rectus. This pattern was also found in the case linked COL6A1/A2 locus but with normal collagen. This finding, and the striking clinical and magnetic resonance imaging concordance between patients with normal and reduced collagen VI in muscle suggest that collagen VI could still be the culprit in several cases with normal collagen expression, or alternatively a primary defect in a protein that closely interacts with collagen VI. Mutation analysis of the collagen 6 genes in cases with normal collagen VI expression is needed to resolve this issue.
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Affiliation(s)
- E Mercuri
- Dubowitz Neuromuscular Centre, Department of Paediatrics, Hammersmith Hospital Faculty of Medicine, Imperial College, London, UK
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Demir E, Sabatelli P, Allamand V, Ferreiro A, Moghadaszadeh B, Makrelouf M, Topaloglu H, Echenne B, Merlini L, Guicheney P. Mutations in COL6A3 cause severe and mild phenotypes of Ullrich congenital muscular dystrophy. Am J Hum Genet 2002; 70:1446-58. [PMID: 11992252 PMCID: PMC419991 DOI: 10.1086/340608] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2001] [Accepted: 03/06/2002] [Indexed: 11/04/2022] Open
Abstract
Ullrich congenital muscular dystrophy (UCMD) is an autosomal recessive disorder characterized by generalized muscular weakness, contractures of multiple joints, and distal hyperextensibility. Homozygous and compound heterozygous mutations of COL6A2 on chromosome 21q22 have recently been shown to cause UCMD. We performed a genomewide screening with microsatellite markers in a consanguineous family with three sibs affected with UCMD. Linkage of the disease to chromosome 2q37 was found in this family and in two others. We analyzed COL6A3, which encodes the alpha3 chain of collagen VI, and identified one homozygous mutation per family. In family I, the three sibs carried an A-->G transition in the splice-donor site of intron 29 (6930+5A-->G), leading to the skipping of exon 29, a partial reduction of collagen VI in muscle biopsy, and an intermediate phenotype. In family II, the patient had an unusual mild phenotype, despite a nonsense mutation, R465X, in exon 5. Analysis of the patient's COL6A3 transcripts showed the presence of various mRNA species-one of which lacked several exons, including the exon containing the nonsense mutation. The deleted splice variant encodes collagen molecules that have a shorter N-terminal domain but that may assemble with other chains and retain a functional role. This could explain the mild phenotype of the patient who was still ambulant at age 18 years and who showed an unusual combination of hyperlaxity and finger contractures. In family III, the patient had a nonsense mutation, R2342X, causing absence of collagen VI in muscle and fibroblasts, and a severe phenotype, as has been described in patients with UCMD. Mutations in COL6A3 are described in UCMD for the first time and illustrate the wide spectrum of phenotypes which can be caused by collagen VI deficiency.
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Affiliation(s)
- Ercan Demir
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
| | - Patrizia Sabatelli
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
| | - Valérie Allamand
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
| | - Ana Ferreiro
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
| | - Behzad Moghadaszadeh
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
| | - Mohamed Makrelouf
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
| | - Haluk Topaloglu
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
| | - Bernard Echenne
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
| | - Luciano Merlini
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
| | - Pascale Guicheney
- INSERM U 523, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris; Istituto di Citomorfologia Normale e Patologica, Consiglio Nazionale delle Ricerche c/o Istituto Ortopedico Rizzoli, and Neuromuscular Unit, Rizzoli Orthopedic Institut, Bologna; Department of Paediatric Neurology, Hacettepe Children's Hospital, Ankara; and Service de Neuropédiatrie, Hôpital Saint Eloi, Montpellier, France
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Vanegas OC, Zhang RZ, Sabatelli P, Lattanzi G, Bencivenga P, Giusti B, Columbaro M, Chu ML, Merlini L, Pepe G. Novel COL6A1 splicing mutation in a family affected by mild Bethlem myopathy. Muscle Nerve 2002; 25:513-9. [PMID: 11932968 DOI: 10.1002/mus.10100] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bethlem myopathy is an early-onset benign myopathy characterized by proximal muscular weakness and multiple flexion contractures. It is a dominantly inherited disorder associated with mutations in the three COL6 genes encoding type VI collagen. We detected a g-->a substitution at +1 position of COL6A1 intron 3 in a four-generation Italian family affected by a mild form of Bethlem myopathy. The mutation results in the activation of a cryptic splice donor site at the 3' end of exon 3, leading to the loss of 66 nucleotides and an "in-frame" deletion of 22 amino acids in the NH2-domain. Molecular analysis on fibroblasts of the propositus showed that the mutated mRNA was present and stable, but the mutated protein could not be detected. Western blot and immunofluorescence analyses showed a decreased level of collagen VI synthesis and deposition in fibroblasts of the propositus. Together, the results suggest that the mutated protein was highly unstable and rapidly degraded, and that the mild phenotype was caused by a reduced amount of normal collagen VI microfibrils. In addition, we demonstrated that lymphocytes can be used for the first mutation screening analysis of patients with Bethlem myopathy.
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Affiliation(s)
- Olga Camacho Vanegas
- Department of Internal Medicine, University of Rome "Tor Vergata," Via Tor Vergata 135, 00133 Roma, Italy
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Magnusson V, Lindqvist AK, Castillejo-López C, Kristjánsdottir H, Steinsson K, Gröndal G, Sturfelt G, Truedsson L, Svenungsson E, Lundberg I, Gunnarsson I, Bolstad AI, Haga HJ, Jonsson R, Klareskog L, Alcocer-Varela J, Alarcón-Segovia D, Terwilliger JD, Gyllensten UB, Alarcón-Riquelme ME. Fine mapping of the SLEB2 locus involved in susceptibility to systemic lupus erythematosus. Genomics 2000; 70:307-14. [PMID: 11161781 DOI: 10.1006/geno.2000.6374] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We have previously reported linkage of systemic lupus erythematosus to chromosome 2q37 in multicase families from Iceland and Sweden. This locus (SLEB2) was identified by linkage to the markers D2S125 and D2S140. In the present study we have analyzed additional microsatellite markers and SNPs covering a region of 30 cM around D2S125 in an extended set of Nordic families (Icelandic, Swedish, and Norwegian). Two-point linkage analysis in these families gave a maximum lod score at the position of markers D2S2585 and D2S2985 (Z = 4.51, PIC = 0.65), by applying a "model-free" pseudo-marker linkage analysis. Based on multipoint linkage analysis in the Nordic families, the most likely location of the SLEB2 locus is estimated to be in the interval between D2S125 and the position of markers D2S2585 and D2S2985, with a peak multipoint lod score of Z = 6.03, assuming a dominant pseudo-marker model. Linkage disequilibrium (LD) analysis was performed using the data from the multicase families and 89 single-case families of Swedish origin, using the same set of markers. The LD analysis showed evidence for association in the single-case and multicase families with locus GAAT3C11 (P < 0.0003), and weak evidence for association was obtained for several markers located telomeric to D2S125 in the multicase families. Thirteen Mexican families were analyzed separately and found not to have linkage to this region. Our results support the presence of the SLEB2 locus at 2q37.
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Affiliation(s)
- V Magnusson
- Department of Genetics and Pathology and Uppsala Genotyping Center, Uppsala University, Uppsala, 751 85, Sweden
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