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Carsillo T, Astrinidis A, Henske EP. Mutations in the tuberous sclerosis complex gene TSC2 are a cause of sporadic pulmonary lymphangioleiomyomatosis. Proc Natl Acad Sci U S A 2000; 97:6085-90. [PMID: 10823953 PMCID: PMC18562 DOI: 10.1073/pnas.97.11.6085] [Citation(s) in RCA: 448] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lymphangioleiomyomatosis (LAM) is a progressive and often fatal interstitial lung disease characterized by a diffuse proliferation of abnormal smooth muscle cells in the lungs. LAM is of unusual interest biologically because it affects almost exclusively young women. LAM can occur as an isolated disorder (sporadic LAM) or in association with tuberous sclerosis complex. Renal angiomyolipomas, which are found in most tuberous sclerosis patients, also occur in 60% of sporadic LAM patients. We previously found TSC2 loss of heterozygosity in 7 of 13 (54%) of angiomyolipomas from sporadic LAM patients, suggesting that LAM and TSC could have a common genetic basis. In this study, we report the identification of somatic TSC2 mutations in five of seven angiomyolipomas from sporadic LAM patients. In all four patients from whom lung tissue was available, the same mutation found in the angiomyolipoma was present in the abnormal pulmonary smooth muscle cells. In no case was the mutation present in normal kidney, morphologically normal lung, or lymphoblastoid cells. Our data demonstrate that somatic mutations in the TSC2 gene occur in the angiomyolipomas and pulmonary LAM cells of women with sporadic LAM, strongly supporting a direct role of TSC2 in the pathogenesis of this disease.
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Affiliation(s)
- T Carsillo
- Department of Medical Oncology, Fox Chase Cancer Center, Philadelphia PA 19111, USA
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302
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Abstract
Autism is a severe neurodevelopmental disorder characterized by communication and social deficits and by stereotyped, repetitive behaviors. The syndrome of autism is highly heritable, is considered to be etiologically heterogeneous and is thought to be the result of multiple, interacting genes. It is more common than previously thought, and has a complex pattern of genetic transmission. From four recently completed genome-wide linkage screens of autism, distal 7q has emerged as the most prominent chromosomal region of interest. Additional support for 7q comes from autistic individuals with gross 7q cytologic abnormalities, and from linkage and association data in families with language and speech disorders. Chromosome 15q11-13 is also of interest because of numerous reports of macroscopic and molecular abnormalities in the region associated with Prader-Willi and Angelman syndromes. In this review, molecular aspects of these data, as well as future avenues of investigation, are discussed.
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Affiliation(s)
- T H Wassink
- Psychiatry Research, MEB, Department of Psychiatry, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA
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305
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Fahsold R, Hoffmeyer S, Mischung C, Gille C, Ehlers C, Kücükceylan N, Abdel-Nour M, Gewies A, Peters H, Kaufmann D, Buske A, Tinschert S, Nürnberg P. Minor lesion mutational spectrum of the entire NF1 gene does not explain its high mutability but points to a functional domain upstream of the GAP-related domain. Am J Hum Genet 2000; 66:790-818. [PMID: 10712197 PMCID: PMC1288164 DOI: 10.1086/302809] [Citation(s) in RCA: 204] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/1999] [Accepted: 10/14/1999] [Indexed: 11/03/2022] Open
Abstract
More than 500 unrelated patients with neurofibromatosis type 1 (NF1) were screened for mutations in the NF1 gene. For each patient, the whole coding sequence and all splice sites were studied for aberrations, either by the protein truncation test (PTT), temperature-gradient gel electrophoresis (TGGE) of genomic PCR products, or, most often, by direct genomic sequencing (DGS) of all individual exons. A total of 301 sequence variants, including 278 bona fide pathogenic mutations, were identified. As many as 216 or 183 of the genuine mutations, comprising 179 or 161 different ones, can be considered novel when compared to the recent findings of Upadhyaya and Cooper, or to the NNFF mutation database. Mutation-detection efficiencies of the various screening methods were similar: 47.1% for PTT, 53.7% for TGGE, and 54.9% for DGS. Some 224 mutations (80.2%) yielded directly or indirectly premature termination codons. These mutations showed even distribution over the whole gene from exon 1 to exon 47. Of all sequence variants determined in our study, <20% represent C-->T or G-->A transitions within a CpG dinucleotide, and only six different mutations also occur in NF1 pseudogenes, with five being typical C-->T transitions in a CpG. Thus, neither frequent deamination of 5-methylcytosines nor interchromosomal gene conversion may account for the high mutation rate of the NF1 gene. As opposed to the truncating mutations, the 28 (10.1%) missense or single-amino-acid-deletion mutations identified clustered in two distinct regions, the GAP-related domain (GRD) and an upstream gene segment comprising exons 11-17. The latter forms a so-called cysteine/serine-rich domain with three cysteine pairs suggestive of ATP binding, as well as three potential cAMP-dependent protein kinase (PKA) recognition sites obviously phosphorylated by PKA. Coincidence of mutated amino acids and those conserved between human and Drosophila strongly suggest significant functional relevance of this region, with major roles played by exons 12a and 15 and part of exon 16.
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Affiliation(s)
- Raimund Fahsold
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Sven Hoffmeyer
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Claudia Mischung
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Christoph Gille
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Christian Ehlers
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Nazan Kücükceylan
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Maher Abdel-Nour
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Andreas Gewies
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Hartmut Peters
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Dieter Kaufmann
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Annegret Buske
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Sigrid Tinschert
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
| | - Peter Nürnberg
- Gemeinschaftspraxis B. Prager & A. Junge, Dresden; Epidauros AG, Bernried; Institut für Medizinische Genetik, Universitätsklinikum Charité, Berlin; Institut für Biochemie, Universitätsklinikum Charité, Berlin; Abteilung Humangenetik, Universität Ulm, Ulm
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306
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Niida Y, Lawrence-Smith N, Banwell A, Hammer E, Lewis J, Beauchamp RL, Sims K, Ramesh V, Ozelius L. Analysis of both TSC1 and TSC2 for germline mutations in 126 unrelated patients with tuberous sclerosis. Hum Mutat 1999; 14:412-22. [PMID: 10533067 DOI: 10.1002/(sici)1098-1004(199911)14:5<412::aid-humu7>3.0.co;2-k] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by the development of multiple hamartomas involving many organs. About two-thirds of the cases are sporadic and appear to represent new mutations. With the cloning of two causative genes, TSC1 and TSC2 it is now possible to analyze both genes in TSC patients and identify germline mutations. Here we report the mutational analysis of the entire coding region of both TSC1 and TSC2 genes in 126 unrelated TSC patients, including 40 familial and 86 sporadic cases, by single-stranded conformational polymorphism (SSCP) analysis followed by direct sequencing. Mutations were identified in a total of 74 (59%) cases, including 16 TSC1 mutations (5 sporadic and 11 familial cases) and 58 TSC2 mutations (42 sporadic and 16 familial cases). Overall, significantly more TSC2 mutations were found in our population, with a relatively equal distribution of mutations between TSC1 and TSC2 among the familial cases, but a marked underrepresentation of TSC1 mutations among the sporadic cases (P = 0.0035, Fisher's exact test). All TSC1 mutations were predicted to be protein truncating. However, in TSC2 13 missense mutations were found, five clustering in the GAP-related domain and three others occurring in exon 16. Upon comparison of clinical manifestations, including the incidence of intellectual disability, we could not find any observable differences between TSC1 and TSC2 patients. Our data help define the distribution and spectrum of mutations associated with the TSC loci and will be useful for both understanding the function of these genes as well as genetic counseling in patients with the disease.
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Affiliation(s)
- Y Niida
- Molecular Neurogenetics Unit, Massachusetts General Hospital, Charlestown, MA 02129, USA
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307
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Mayer K, Ballhausen W, Rott HD. Mutation screening of the entire coding regions of the TSC1 and the TSC2 gene with the protein truncation test (PTT) identifies frequent splicing defects. Hum Mutat 1999; 14:401-11. [PMID: 10533066 DOI: 10.1002/(sici)1098-1004(199911)14:5<401::aid-humu6>3.0.co;2-r] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Mutation analyses in tuberous sclerosis (TSC) have reported a wide variety of disease-causing aberrations in the two known predisposing genes, TSC1 and TSC2 on chromosomes 9q34 and 16p13, comprising mainly small mutations distributed over the entire genes. So far, all known TSC1 mutations as well as the majority of TSC2 mutations truncate the proteins hamartin and tuberin, respectively. We describe for the first time an RNA-based screening of the entire coding regions of both TSC genes for truncating mutations applying the protein truncation test (PTT). Simultaneous investigation of both TSC genes in a group of 48 unassigned TSC patients, which were previously tested to exclude large intragenic TSC2 rearrangements, revealed aberrant migrating polypeptides resulting from truncating mutations in nine TSC1 cases and in 16 TSC2 cases while three TSC2 cases showed enlarged proteins. TSC1 mutations include two nonsense mutations, four insertions, and three splice mutations. Nineteen mutations identified in TSC2 were composed of four different nonsense mutations in five patients, one deletion, one insertion, and seven different splicing aberrations due to at least eight different mutations found in 12 patients. Additional predicted truncating mutations according to PTT without possible identification of the causative alteration allowed assignment to TSC1 in one and TSC2 in seven cases. Twelve patients without abnormalities in the PTT are assumed to harbor missense mutations, probably in TSC2. The high proportion of TSC2 splicing aberrations strengthens the importance of intronic disease-causing mutations and the application of RNA-based screening methods to confirm their consequences.
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Affiliation(s)
- K Mayer
- Institute of Human Genetics, University of Erlangen-Nuremberg, Erlangen, Germany.
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308
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Onda H, Lueck A, Marks PW, Warren HB, Kwiatkowski DJ. Tsc2(+/-) mice develop tumors in multiple sites that express gelsolin and are influenced by genetic background. J Clin Invest 1999; 104:687-95. [PMID: 10491404 PMCID: PMC408440 DOI: 10.1172/jci7319] [Citation(s) in RCA: 291] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Tuberous sclerosis (TSC) is an autosomal dominant genetic disorder in which benign hamartomas develop in multiple organs, caused by mutations in either TSC1 or TSC2. We developed a murine model of Tsc2 disease using a gene targeting approach. Tsc2-null embryos die at embryonic days 9.5-12.5 from hepatic hypoplasia. Tsc2 heterozygotes display 100% incidence of multiple bilateral renal cystadenomas, 50% incidence of liver hemangiomas, and 32% incidence of lung adenomas by 15 months of age. Progression to renal carcinoma, fatal bleeding from the liver hemangiomas, and extremity angiosarcomas all occur at a rate of less than 10%. The renal cystadenomas develop from intercalated cells of the cortical collecting duct and uniformly express gelsolin at high levels, enabling detection of early neoplastic lesions. The tumor expression pattern of the mice is influenced by genetic background, with fewer large renal cystadenomas in the outbred Black Swiss background and more angiosarcomas in 129/SvJae chimeric mice. The slow growth of the tumors in the heterozygote mice matches the limited growth potential of the great majority of TSC hamartomas, and the influence of genetic background on phenotype correlates with the marked variability in expression of TSC seen in patients.
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Affiliation(s)
- H Onda
- Genetics Laboratory, Hematology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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309
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Jones AC, Austin J, Hansen N, Hoogendoorn B, Oefner PJ, Cheadle JP, O’Donovan MC. Optimal Temperature Selection for Mutation Detection by Denaturing HPLC and Comparison to Single-Stranded Conformation Polymorphism and Heteroduplex Analysis. Clin Chem 1999. [DOI: 10.1093/clinchem/45.8.1133] [Citation(s) in RCA: 197] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Background: Denaturing HPLC (DHPLC) is a semi-automated method for detecting unknown DNA sequence variants. The sensitivity of the method is dependent on the temperature at which the analysis is undertaken, the selection of which is dependent on operator experience. To circumvent this, software has been developed for predicting the optimal temperature for DHPLC analysis. We examined the utility of this software.
Methods: To maximize the relevance of our data for other investigators, we have screened 42 different amplimers from CFTR, TSC1, and TSC2. The samples consisted of 103 unique sequence heterozygotes and 126 wild-type homozygous controls.
Results: At the temperature recommended by the software, 96% (99 of 103) of heterozygotes and all of the wild-type controls were correctly classified. This compares favorably with sensitivities of 85% for single-stranded conformation polymorphism and 82% for gel-based heteroduplex analyses of the same fragments.
Conclusions: Software-optimized DHPLC is a highly sensitive method for mutation detection. However, where sensitivity >96% is required, our data suggest that in addition to the recommended temperature, fragments should also be run at the recommended temperature plus 2 °C.
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Affiliation(s)
| | | | - Nancy Hansen
- Stanford DNA Sequencing and Technology Center, Palo Alto, CA 94304
| | | | - Peter J Oefner
- Stanford DNA Sequencing and Technology Center, Palo Alto, CA 94304
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