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Matsumoto A, Tulyeu J, Furukawa R, Watanabe C, Monden Y, Nozaki Y, Mori M, Namekawa M, Jimbo EF, Aihara T, Yamagata T, Osaka H. A case of severe Alexander disease with de novo c. 239 T > C, p.(F80S), in GFAP. Brain Dev 2018; 40:587-591. [PMID: 29573842 DOI: 10.1016/j.braindev.2018.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/21/2018] [Accepted: 03/09/2018] [Indexed: 11/16/2022]
Abstract
Alexander disease (AxD) is a progressive neurodegenerative disease caused by a mutation in the glial fibrillary acid protein (GFAP) gene. A 4-year-old boy presented several times with hemiclonic seizures with eye deviation for a few minutes at 28 days after birth. Electroencephalogram showed independent sharp waves in the right and left temporal area. Magnetic resonance imaging showed high intensity T1-weighted images in the white matter of the frontal lobe and basal ganglia. He showed no head control at 4 years of age, and his weight gain was insufficient. He did not show macrocephaly. At 4 years of age, he died of bacterial pneumonia and septic shock. He was diagnosed with AxD, and direct sequencing revealed a de novo known mutation, c. 239 T > C, p.(F80S), in GFAP. Hela and U2-OS cells transfected with GFAP cDNA with c. 239 T > C showed dot-like cytoplasmic aggregation, similar to R239C, a common mutation found in severe infantile AxD. Aggregation in the cytoplasm caused by a GFAP mutation is a hallmark of AxD. Although there is only one previous report of a patient with an F80S mutation, our data support that F80S can cause the severe, infantile form of AxD.
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Affiliation(s)
- Ayumi Matsumoto
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Janyerkye Tulyeu
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Rieko Furukawa
- Department of Pediatric Medical Imaging, Jichi Medical University, Tochigi, Japan
| | - Chika Watanabe
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Yukifumi Monden
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Yasuyuki Nozaki
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Masato Mori
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Michito Namekawa
- Health Administration Center, Saitama Prefectural University, Saitama, Japan
| | - Eriko F Jimbo
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Toshinori Aihara
- Department of Pediatric Medical Imaging, Jichi Medical University, Tochigi, Japan
| | | | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan.
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Aggregation-prone GFAP mutation in Alexander disease validated using a zebrafish model. BMC Neurol 2017; 17:175. [PMID: 28882119 PMCID: PMC5590178 DOI: 10.1186/s12883-017-0938-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 08/03/2017] [Indexed: 11/26/2022] Open
Abstract
Background Alexander disease (AxD) is an astrogliopathy that predominantly affects the white matter of the central nervous system (CNS), and is caused by a mutation in the gene encoding the glial fibrillary acidic protein (GFAP), an intermediate filament primarily expressed in astrocytes and ependymal cells. The main pathologic feature of AxD is the presence of Rosenthal fibers (RFs), homogeneous eosinophilic inclusions found in astrocytes. Because of difficulties in procuring patient’ CNS tissues and the presence of RFs in other pathologic conditions, there is a need to develop an in vivo assay that can determine whether a mutation in the GFAP results in aggregation and is thus disease-causing. Methods We found a GFAP mutation (c.382G > A, p.Asp128Asn) in a 68-year-old man with slowly progressive gait disturbance with tendency to fall. The patient was tentatively diagnosed with AxD based on clinical and radiological findings. To develop a vertebrate model to assess the aggregation tendency of GFAP, we expressed several previously reported mutant GFAPs and p.Asp128Asn GFAP in zebrafish embryos. Results The most common GFAP mutations in AxD, p.Arg79Cys, p.Arg79His, p.Arg239Cys and p.Arg239His, and p.Asp128Asn induced a significantly higher number of GFAP aggregates in zebrafish embryos than wild-type GFAP. Conclusions The p.Asp128Asn GFAP mutation is likely to be a disease-causing mutation. Although it needs to be tested more extensively in larger case series, the zebrafish assay system presented here would help clinicians determine whether GFAP mutations identified in putative AxD patients are disease-causing.
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Higgins EM, Bos JM, Mason-Suares H, Tester DJ, Ackerman JP, MacRae CA, Sol-Church K, Gripp KW, Urrutia R, Ackerman MJ. Elucidation of MRAS-mediated Noonan syndrome with cardiac hypertrophy. JCI Insight 2017; 2:e91225. [PMID: 28289718 DOI: 10.1172/jci.insight.91225] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Noonan syndrome (NS; MIM 163950) is an autosomal dominant disorder and a member of a family of developmental disorders termed "RASopathies," which are caused mainly by gain-of-function mutations in genes encoding RAS/MAPK signaling pathway proteins. Whole exome sequencing (WES) and trio-based genomic triangulation of a 15-year-old female with a clinical diagnosis of NS and concomitant cardiac hypertrophy and her unaffected parents identified a de novo variant in MRAS-encoded RAS-related protein 3 as the cause of her disease. Mutation analysis using in silico mutation prediction tools and molecular dynamics simulations predicted the identified variant, p.Gly23Val-MRAS, to be damaging to normal protein function and adversely affect effector interaction regions and the GTP-binding site. Subsequent ectopic expression experiments revealed a 40-fold increase in MRAS activation for p.Gly23Val-MRAS compared with WT-MRAS. Additional biochemical assays demonstrated enhanced activation of both RAS/MAPK pathway signaling and downstream gene expression in cells expressing p.Gly23Val-MRAS. Mutational analysis of MRAS in a cohort of 109 unrelated patients with phenotype-positive/genotype-negative NS and cardiac hypertrophy yielded another patient with a sporadic de novo MRAS variant (p.Thr68Ile, c.203C>T). Herein, we describe the discovery of mutations in MRAS in patients with NS and cardiac hypertrophy, establishing MRAS as the newest NS with cardiac hypertrophy-susceptibility gene.
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Affiliation(s)
| | - J Martijn Bos
- Department of Molecular Pharmacology and Experimental Therapeutics and Windland Smith Rice Sudden Death Genomics Laboratory.,Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Heather Mason-Suares
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts, USA.,Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - David J Tester
- Department of Molecular Pharmacology and Experimental Therapeutics and Windland Smith Rice Sudden Death Genomics Laboratory.,Department of Cardiovascular Diseases/Division of Heart Rhythm Services, Mayo Clinic, Rochester, Minnesota, USA
| | - Jaeger P Ackerman
- Department of Molecular Pharmacology and Experimental Therapeutics and Windland Smith Rice Sudden Death Genomics Laboratory
| | - Calum A MacRae
- Divisions of Cardiovascular Medicine and Network Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.,Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | | | - Karen W Gripp
- Center for Applied Clinical Genomics and.,Division of Medical Genetics, Alfred I. duPont Hospital for Children, Wilmington, Delaware, USA
| | - Raul Urrutia
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA.,Departments of Biochemistry and Molecular Biology, Biophysics, and Medicine, Laboratory of Epigenetics and Chromatin Dynamics, Epigenomics Translational Program, Gastroenterology Research Unit, Mayo Clinic, Rochester, Minnesota, USA
| | - Michael J Ackerman
- Department of Molecular Pharmacology and Experimental Therapeutics and Windland Smith Rice Sudden Death Genomics Laboratory.,Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota, USA.,Department of Cardiovascular Diseases/Division of Heart Rhythm Services, Mayo Clinic, Rochester, Minnesota, USA
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