1
|
Ehrhart F, Jacobsen A, Rigau M, Bosio M, Kaliyaperumal R, Laros JFJ, Willighagen EL, Valencia A, Roos M, Capella-Gutierrez S, Curfs LMG, Evelo CT. A catalogue of 863 Rett-syndrome-causing MECP2 mutations and lessons learned from data integration. Sci Data 2021; 8:10. [PMID: 33452270 PMCID: PMC7810705 DOI: 10.1038/s41597-020-00794-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/30/2020] [Indexed: 11/09/2022] Open
Abstract
Rett syndrome (RTT) is a rare neurological disorder mostly caused by a genetic variation in MECP2. Making new MECP2 variants and the related phenotypes available provides data for better understanding of disease mechanisms and faster identification of variants for diagnosis. This is, however, currently hampered by the lack of interoperability between genotype-phenotype databases. Here, we demonstrate on the example of MECP2 in RTT that by making the genotype-phenotype data more Findable, Accessible, Interoperable, and Reusable (FAIR), we can facilitate prioritization and analysis of variants. In total, 10,968 MECP2 variants were successfully integrated. Among these variants 863 unique confirmed RTT causing and 209 unique confirmed benign variants were found. This dataset was used for comparison of pathogenicity predicting tools, protein consequences, and identification of ambiguous variants. Prediction tools generally recognised the RTT causing and benign variants, however, there was a broad range of overlap Nineteen variants were identified that were annotated as both disease-causing and benign, suggesting that there are additional factors in these cases contributing to disease development. Measurement(s) | Rett syndrome • phenotype • MECP2 Gene | Technology Type(s) | digital curation • network analysis | Sample Characteristic - Organism | Homo sapiens |
Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.13359476
Collapse
Affiliation(s)
- Friederike Ehrhart
- Department of Bioinformatics - BiGCaT, NUTRIM School of Nutrition and Translational Research in Metabolism, MHeNS School of Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands. .,GKC - Rett Expertise Centre, Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Annika Jacobsen
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Maria Rigau
- Barcelona Supercomputing Centre (BSC), Barcelona, Spain
| | - Mattia Bosio
- Barcelona Supercomputing Centre (BSC), Barcelona, Spain
| | - Rajaram Kaliyaperumal
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Jeroen F J Laros
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Egon L Willighagen
- Department of Bioinformatics - BiGCaT, NUTRIM School of Nutrition and Translational Research in Metabolism, MHeNS School of Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Alfonso Valencia
- Barcelona Supercomputing Centre (BSC), Barcelona, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Marco Roos
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Leopold M G Curfs
- GKC - Rett Expertise Centre, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Chris T Evelo
- Department of Bioinformatics - BiGCaT, NUTRIM School of Nutrition and Translational Research in Metabolism, MHeNS School of Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,GKC - Rett Expertise Centre, Maastricht University Medical Center, Maastricht, The Netherlands
| |
Collapse
|
2
|
Comprehensive Analysis of GABA A-A1R Developmental Alterations in Rett Syndrome: Setting the Focus for Therapeutic Targets in the Time Frame of the Disease. Int J Mol Sci 2020; 21:ijms21020518. [PMID: 31947619 PMCID: PMC7014188 DOI: 10.3390/ijms21020518] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/03/2020] [Accepted: 01/10/2020] [Indexed: 02/08/2023] Open
Abstract
Rett syndrome, a serious neurodevelopmental disorder, has been associated with an altered expression of different synaptic-related proteins and aberrant glutamatergic and γ-aminobutyric acid (GABA)ergic neurotransmission. Despite its severity, it lacks a therapeutic option. Through this work we aimed to define the relationship between MeCP2 and GABAA.-A1 receptor expression, emphasizing the time dependence of such relationship. For this, we analyzed the expression of the ionotropic receptor subunit in different MeCP2 gene-dosage and developmental conditions, in cells lines, and in primary cultured neurons, as well as in different developmental stages of a Rett mouse model. Further, RNAseq and systems biology analysis was performed from post-mortem brain biopsies of Rett patients. We observed that the modulation of the MeCP2 expression in cellular models (both Neuro2a (N2A) cells and primary neuronal cultures) revealed a MeCP2 positive effect on the GABAA.-A1 receptor subunit expression, which did not occur in other proteins such as KCC2 (Potassium-chloride channel, member 5). In the Mecp2+/− mouse brain, both the KCC2 and GABA subunits expression were developmentally regulated, with a decreased expression during the pre-symptomatic stage, while the expression was variable in the adult symptomatic mice. Finally, the expression of the gamma-aminobutyric acid (GABA) receptor-related synaptic proteins from the postmortem brain biopsies of two Rett patients was evaluated, specifically revealing the GABA A1R subunit overexpression. The identification of the molecular changes along with the Rett syndrome prodromic stages strongly endorses the importance of time frame when addressing this disease, supporting the need for a neurotransmission-targeted early therapeutic intervention.
Collapse
|
3
|
Abstract
Rett syndrome (RTT) has experienced remarkable progress over the past three decades since emerging as a disorder of worldwide proportions, particularly with discovery of the linkage of RTT to MECP2 mutations. The advances in clinical research and the increasing pace of basic science investigations have accelerated the pattern of discovery and understanding. Clinical trials are ongoing and others are planned. A review of these events and the prospects for continued success are highlighted below. The girls and women encountered today with RTT are, overall, in better general, neurologic, and behavioral health than those encountered earlier. This represents important progress worldwide from the concerted efforts of a broadly based and diverse clinical and basic research consortium as well as the efforts of parents, family, and friends.
Collapse
|
4
|
Singleton MK, Gonzales ML, Leung KN, Yasui DH, Schroeder DI, Dunaway K, LaSalle JM. MeCP2 is required for global heterochromatic and nucleolar changes during activity-dependent neuronal maturation. Neurobiol Dis 2011; 43:190-200. [PMID: 21420494 DOI: 10.1016/j.nbd.2011.03.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 01/24/2011] [Accepted: 03/11/2011] [Indexed: 10/18/2022] Open
Abstract
Mutations in MECP2, encoding methyl CpG binding protein 2, cause the neurodevelopmental disorder Rett syndrome. MeCP2 is an abundant nuclear protein that binds to chromatin and modulates transcription in response to neuronal activity. Prior studies of MeCP2 function have focused on specific gene targets of MeCP2, but a more global role for MeCP2 in neuronal nuclear maturation has remained unexplored. MeCP2 levels increase during postnatal brain development, coinciding with dynamic changes in neuronal chromatin architecture, particularly detectable as changes in size, number, and location of nucleoli and perinucleolar heterochromatic chromocenters. To determine a potential role for MeCP2 in neuronal chromatin maturational changes, we measured nucleoli and chromocenters in developing wild-type and Mecp2-deficient mouse cortical sections, as well as mouse primary cortical neurons and a human neuronal cell line following induced maturation. Mecp2-deficient mouse neurons exhibited significant differences in nucleolar and chromocenter number and size, as more abundant, smaller nucleoli in brain and primary neurons compared to wild-type, consistent with delayed neuronal nuclear maturation in the absence of MeCP2. Primary neurons increased chromocenter size following depolarization in wild-type, but not Mecp2-deficient cultures. Wild-type MECP2e1 over-expression in human SH-SY5Y cells was sufficient to induce significantly larger nucleoli, but not a T158M mutation of the methyl-binding domain. These results suggest that, in addition to the established role of MeCP2 in transcriptional regulation of specific target genes, the global chromatin-binding function of MeCP2 is essential for activity-dependent global chromatin dynamics during postnatal neuronal maturation.
Collapse
Affiliation(s)
- Malaika K Singleton
- Department of Medical Microbiology and Immunology, School of Medicine, Genome Center, and MIND Institute, University of California, Davis, CA 95616, USA
| | | | | | | | | | | | | |
Collapse
|
5
|
Hadzsiev K, Polgar N, Bene J, Komlosi K, Karteszi J, Hollody K, Kosztolanyi G, Renieri A, Melegh B. Analysis of Hungarian patients with Rett syndrome phenotype for MECP2, CDKL5 and FOXG1 gene mutations. J Hum Genet 2010; 56:183-7. [DOI: 10.1038/jhg.2010.156] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
6
|
Monnerat LS, Moreira ADS, Alves MCV, Bonvicino CR, Vargas FR. Identification and characterization of novel sequence variations in MECP2 gene in Rett syndrome patients. Brain Dev 2010; 32:843-8. [PMID: 20031356 DOI: 10.1016/j.braindev.2009.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 10/06/2009] [Accepted: 11/21/2009] [Indexed: 10/20/2022]
Abstract
Rett syndrome (RS) is a neurodevelopmental disorder caused by mutations in MECP2 gene. Exons 2, 3, and 4, in addition to intronic and 3'UTR adjacent regions, were sequenced in 80 patients with RS. Twenty-nine sequence variations were detected in 49 patients, 34 (69.4%) patients with the classic form of RS, and 15 (30.6%) patients with atypical forms of RS. Thirteen of the 29 detected mutations represent novel sequence variations. Missense mutation T158M was the most commonly observed mutation, detected in nine patients (11.2%). Six hotspot pathogenic mutations (R133C, T158M, R168X, R255X, R270X, and R294X) were responsible for the phenotype in 26/80 patients (32.5%).
Collapse
|
7
|
Baris I, Battaloglu E. A multiplexed ARMS-PCR approach for the detection of common MECP2 mutations. Genet Test Mol Biomarkers 2009; 13:19-22. [PMID: 19309269 DOI: 10.1089/gtmb.2008.0051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Rett syndrome (RTT), an X-linked dominant neurodevelopmental disorder, is caused mainly by de novo mutations in the methyl-CpG-binding protein 2 gene (MECP2). Although more than 200 different MECP2 mutations have been identified throughout the gene, 7 of those (p.R133C, p.T158M, p.R168X, p.R255X, p.R270X, p.R294X, and p.R306C) account for up to two-thirds of pathogenic mutations in RTT patients. A rapid and efficient screening strategy for these mutations can be used as a preliminary step for genetic diagnosis of RTT. The current protocols used for this purpose are of high cost and require special equipment. We have designed a simpler multiplex amplification refractory mutation system (ARMS)-PCR strategy that allows identification of these common MECP2 mutant alleles in four PCR reactions. The assay was tested in 14 RTT patients who were previously genotyped using PCR-restriction fragment length polymorphism and DNA sequencing. A complete concordance was observed between the results of the two methods. The multiplex ARMS-PCR does not require any special equipment, and it provides rapid, reproducible, and cost-effective detection of common MECP2 mutations. The assay can be carried out efficiently in a standard molecular genetics laboratory and suitable as a preliminary screen for all patients with RTT diagnosis.
Collapse
Affiliation(s)
- Ibrahim Baris
- Department of Molecular Biology and Genetics, Bogazici University, Istanbul, Turkey.
| | | |
Collapse
|
8
|
Percy AK, Lane JB, Childers J, Skinner S, Annese F, Barrish J, Caeg E, Glaze DG, MacLeod P. Rett syndrome: North American database. J Child Neurol 2007; 22:1338-41. [PMID: 18174548 DOI: 10.1177/0883073807308715] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The International Rett Syndrome Association (IRSA) North American database is the first comprehensive compilation of information in the United States and Canada on individuals with Rett syndrome or with another diagnosis in association with MECP2 mutations. The database contains specific information by diagnosis, mutation status, and mutation type and frequency on 1928 participants. Among the 1928 participants, 85.5% were typical, 13.4% were atypical, and 1.1% had MECP2 mutations but did not have Rett syndrome. MECP2 mutations were identified in 914 of 1059 participants (86%): 799 of 870 (92%) participants with typical Rett syndrome had an MECP2 mutation, 94 of 162 (58%) with atypical Rett syndrome had a mutation, and all 21 individuals diagnosed as Not Rett syndrome had a mutation. Missense-type mutations (39.0%) were slightly more common than nonsense type (35.1%). Individual mutation frequency for the 8 common mutations varied from 11.9% for T158M to 4.4% for R106W; large deletions accounted for 6.4% and C-terminal truncations occurred in 8.8%. The remaining mutations (14.3%) occurred singly or in small numbers. This database provides a unique resource for expanding our understanding of Rett syndrome, for comparison with other national databases, and for future study including organization of clinical trials based on the expected emergence of fundamental therapies.
Collapse
Affiliation(s)
- Alan K Percy
- Civitan International Research Center, University of Alabama at Birmingham, 35294-0021, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Matijević T, Knezević J, Barisić I, Resić B, Culić V, Pavelić J. The MECP2 gene mutation screening in Rett syndrome patients from Croatia. Ann N Y Acad Sci 2007; 1091:225-32. [PMID: 17341617 DOI: 10.1196/annals.1378.069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Rett syndrome (RTT) is an X-linked dominant neurodevelopmental disorder almost exclusively affecting females and is usually sporadic. Mutations in MECP2 gene have been found in more than 80% of females with typical features of RTT. In this study, we analyzed 15 sporadic cases of RTT. In 7 of 15 patients (47%), we detected pathogenic mutations in the coding parts of MECP2 fourth exon. We found two missense (T158M, R133C), two nonsense (R168X, R270X), two frameshift mutations (P217fs and a double deletion of 28-bp at 1132-1159 and 10-bp at 1167-1176), and one in-frame deletion (L383_E392del10). To our knowledge, the last two mutations have not been reported yet. We also detected one previously described polymorphism (S194S). In conclusion, these results show that the fourth exon should be the first one analyzed because it harbors most of the known mutations. Moreover, mutation-negative cases should be further analyzed for gross rearrangements. This is the first study of its kind in Croatia and it enabled us to give the patients an early confirmation of RTT diagnosis.
Collapse
Affiliation(s)
- Tanja Matijević
- Rudjer Bosković Institute, Division of Molecular Medicine, Laboratory of Molecular Oncology, Bijenicka 54, 10002 Zagreb, Croatia
| | | | | | | | | | | |
Collapse
|
10
|
Knudsen GPS, Neilson TCS, Pedersen J, Kerr A, Schwartz M, Hulten M, Bailey MES, Orstavik KH. Increased skewing of X chromosome inactivation in Rett syndrome patients and their mothers. Eur J Hum Genet 2006; 14:1189-94. [PMID: 16823396 DOI: 10.1038/sj.ejhg.5201682] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Rett syndrome is a largely sporadic, X-linked neurological disorder with a characteristic phenotype, but which exhibits substantial phenotypic variability. This variability has been partly attributed to an effect of X chromosome inactivation (XCI). There have been conflicting reports regarding incidence of skewed X inactivation in Rett syndrome. In rare familial cases of Rett syndrome, favourably skewed X inactivation has been found in phenotypically normal carrier mothers. We have investigated the X inactivation pattern in DNA from blood and buccal cells of sporadic Rett patients (n=96) and their mothers (n=84). The mean degree of skewing in blood was higher in patients (70.7%) than controls (64.9%). Unexpectedly, the mothers of these patients also had a higher mean degree of skewing in blood (70.8%) than controls. In accordance with these findings, the frequency of skewed (XCI > or =80%) X inactivation in blood was also higher in both patients (25%) and mothers (30%) than in controls (11%). To test whether the Rett patients with skewed X inactivation were daughters of skewed mothers, 49 mother-daughter pairs were analysed. Of 14 patients with skewed X inactivation, only three had a mother with skewed X inactivation. Among patients, mildly affected cases were shown to be more skewed than more severely affected cases, and there was a trend towards preferential inactivation of the paternally inherited X chromosome in skewed cases. These findings, particularly the greater degree of X inactivation skewing in Rett syndrome patients, are of potential significance in the analysis of genotype-phenotype correlations in Rett syndrome.
Collapse
Affiliation(s)
- Gun Peggy S Knudsen
- Faculty Division Rikshospitalet, Department of Medical Genetics, University of Oslo, Oslo, Norway.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Fukuda T, Yamashita Y, Nagamitsu S, Miyamoto K, Jin JJ, Ohmori I, Ohtsuka Y, Kuwajima K, Endo S, Iwai T, Yamagata H, Tabara Y, Miki T, Matsuishi T, Kondo I. Methyl-CpG binding protein 2 gene (MECP2) variations in Japanese patients with Rett syndrome: pathological mutations and polymorphisms. Brain Dev 2005; 27:211-7. [PMID: 15737703 DOI: 10.1016/j.braindev.2004.06.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2004] [Revised: 05/18/2004] [Accepted: 06/05/2004] [Indexed: 10/26/2022]
Abstract
A total of 45 different mutations of methyl-CpG-binding protein 2 gene (MECP2) were identified in 145 of 219 Japanese patients with typical or atypical Rett syndrome (RTT) (66.2%). A missense mutation, T158M was the most common mutation of MECP2, identified in 22 (19.1%) patients, followed by four nonsense mutations, R168X (14.8%), R270X (13.0%), R255X (9.6%), and R294X (6.1%) in 115 patients with classical RTT. Two missense mutations, R133C (33.3%) and R306C (23.3%), and a nonsense mutation, R294X (13.3%), were common in 30 patients with atypical RTT, including the preserved speech variant (PSV). Frameshift mutations due to nucleotide deletion or insertion were identified in 22 patients with MECP2 mutations, and one of them had a 3.6 kb deletion encompassing exons 3 and 4. Three patients with classical RTT had a splicing anomaly. The wide spectrum of phenotypic variability in patients with RTT has been considered to be correlated with the mutation type and location in MECP2, and X-inactivation. However, most patients showed a random X-inactivation pattern evaluated by an androgen receptor gene polymorphism in this study, suggesting that a skewed X-inactivation might not be a main modification factor on clinical phenotypes of RTT. In addition, three new missense mutations, P176R, A378V and T479M, were identified in patients with RTT, but also in healthy Japanese, indicating that these mutations are non-pathogenic in Japanese. Information about rare polymorphic variations is very important for the molecular diagnosis of RTT, although rare polymorphic variants might differ among ethnic groups.
Collapse
Affiliation(s)
- Takayuki Fukuda
- Department of Medical Genetics, Ehime University School of Medicine, Onsen-gun, Ehime 791-0295, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Chae JH, Hwang H, Hwang YS, Cheong HJ, Kim KJ. Influence of MECP2 gene mutation and X-chromosome inactivation on the Rett syndrome phenotype. J Child Neurol 2004; 19:503-8. [PMID: 15526954 DOI: 10.1177/08830738040190070501] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To date, approximately 200 different mutations in the MECP2 gene have been identified. We analyzed the entire coding sequence of the MECP2 gene and the X-chromosome inactivation pattern in 42 sporadic cases of Rett syndrome. Of the 42 patients, 30 had pathogenic mutations, including 14 different mutations: 9 missense mutations, 4 nonsense mutations, and 1 frameshift mutation. One was a novel mutation (S134P). There was a tendency for patients who had a nonsense mutation in the transcriptional repression domain region to show earlier onset of regression and more severe language retardation than patients with a mutation in the methyl-CpG binding domain region. However, the parameters of clinical severity were variable among patients with the same type of mutation, depending on the pattern of X-chromosome inactivation. This study suggests that the X-chromosome inactivation pattern can modify the phenotype of Rett syndrome, which is primarily determined by the type and site of MECP2 gene mutation.
Collapse
Affiliation(s)
- Jong Hee Chae
- Department of Pediatrics, Seoul National University College of Medicine, 28 Yongon-dong, Jongnogu, Seoul 110-744, Korea
| | | | | | | | | |
Collapse
|
13
|
Naidu S, Bibat G, Kratz L, Kelley RI, Pevsner J, Hoffman E, Cuffari C, Rohde C, Blue ME, Johnston MV. Clinical variability in Rett syndrome. J Child Neurol 2003; 18:662-8. [PMID: 14649546 DOI: 10.1177/08830738030180100801] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The clinical variability of Rett syndrome, associated with mutations in the MECP2 gene, varies from classically symptomatic female patients to asymptomatic female patients, and male patients who have none of the diagnostic features considered pathognomonic of this disease. Multiple factors contribute to this variability. In our studies, mutations closer to the amino-terminus, prior to amino acid 255, led to severe clinical manifestations, such as inability to walk, severe dysphagia, and urinary organic acid abnormalities, compared with mutations toward the carboxyl-terminus. However, we found no correlation between severity and mutation type (missense versus nonsense). Despite the importance of mutation location to clinical severity, the widely varying severity within the same mutation suggests that in females, X-chromosome inactivation or other epigenetic phenomena also have roles in determining severity. We propose that stages 1 and 2 of the disease are a consequence of failed, time-linked, postnatal expression of MeCP2 in cerebellar neurons. This, in association with glutamate N-methyl-D-aspartate receptor-mediated neuroexcitotoxic injury to the differentiating neurons, results in the transient age-specific autistic-like behavior, motor, and cognitive dysfunction associated with these stages.
Collapse
Affiliation(s)
- SakkuBai Naidu
- Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD 21205, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|