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Mykins M, Bridges B, Jo A, Krishnan K. Multidimensional Analysis of a Social Behavior Identifies Regression and Phenotypic Heterogeneity in a Female Mouse Model for Rett Syndrome. J Neurosci 2024; 44:e1078232023. [PMID: 38199865 PMCID: PMC10957218 DOI: 10.1523/jneurosci.1078-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 11/01/2023] [Accepted: 11/17/2023] [Indexed: 01/12/2024] Open
Abstract
Regression is a key feature of neurodevelopmental disorders such as autism spectrum disorder, Fragile X syndrome, and Rett syndrome (RTT). RTT is caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2). It is characterized by an early period of typical development with subsequent regression of previously acquired motor and speech skills in girls. The syndromic phenotypes are individualistic and dynamic over time. Thus far, it has been difficult to capture these dynamics and syndromic heterogeneity in the preclinical Mecp2-heterozygous female mouse model (Het). The emergence of computational neuroethology tools allows for robust analysis of complex and dynamic behaviors to model endophenotypes in preclinical models. Toward this first step, we utilized DeepLabCut, a marker-less pose estimation software to quantify trajectory kinematics and multidimensional analysis to characterize behavioral heterogeneity in Het in the previously benchmarked, ethologically relevant social cognition task of pup retrieval. We report the identification of two distinct phenotypes of adult Het: Het that display a delay in efficiency in early days and then improve over days like wild-type mice and Het that regress and perform worse in later days. Furthermore, regression is dependent on age and behavioral context and can be detected in the initial days of retrieval. Together, the novel identification of two populations of Het suggests differential effects on neural circuitry, opens new avenues to investigate the underlying molecular and cellular mechanisms of heterogeneity, and designs better studies for stratifying therapeutics.
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Affiliation(s)
- Michael Mykins
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Benjamin Bridges
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Angela Jo
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Keerthi Krishnan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
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Neul JL, Percy AK, Benke TA, Berry-Kravis EM, Glaze DG, Peters SU, Marsh ED, An D, Bishop KM, Youakim JM. Trofinetide Treatment Demonstrates a Benefit Over Placebo for the Ability to Communicate in Rett Syndrome. Pediatr Neurol 2024; 152:63-72. [PMID: 38232652 DOI: 10.1016/j.pediatrneurol.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/27/2023] [Accepted: 11/18/2023] [Indexed: 01/19/2024]
Abstract
BACKGROUND Trofinetide was approved by the US Food and Drug Administration for the treatment of Rett syndrome (RTT) in March 2023. Benefiting the ability to communicate in RTT is often identified as the most important caregiver goal for new therapies. This analysis reports the communication-related end points from the phase 3 LAVENDER study of trofinetide in RTT. METHODS Females with RTT, aged five to 20 years, were randomized 1:1 to trofinetide or placebo for 12 weeks. Secondary efficacy end points related to communication were based on change from baseline to week 12 and included the caregiver-rated Communication and Symbolic Behavior Scales Developmental Profile™ Infant-Toddler Checklist (CSBS-DP-IT) Social Composite score (key secondary end point; scores ranged from 0 to 26 [higher scores indicated better communication]) and novel clinician rating scales (0 [normal] to 7 [severe impairment]) measuring the ability to communicate choices nonverbally (RTT-COMC) and verbally (RTT-VCOM). RESULTS Trofinetide demonstrated a statistically significant difference versus placebo for the CSBS-DP-IT Social Composite score (least squares mean [LSM] difference = 1.0; 95% confidence interval [CI], 0.3 to 1.7; P = 0.0064; Cohen's d effect size = 0.43) and a nominally significant difference for the RTT-COMC (LSM difference: -0.3; 95% CI, -0.6 to -0.0; P = 0.0257; Cohen's d effect size = 0.36). As expected, there was no difference for the RTT-VCOM. CONCLUSIONS Significant treatment benefit for trofinetide versus placebo was observed in scales measuring the ability to communicate. These scales may be appropriate for future clinical studies in RTT and other neurodevelopmental disorders.
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Affiliation(s)
- Jeffrey L Neul
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Alan K Percy
- University of Alabama at Birmingham, Birmingham, Alabama
| | - Timothy A Benke
- Children's Hospital of Colorado, University of Colorado School of Medicine, Aurora, Colorado
| | | | - Daniel G Glaze
- Texas Children's Hospital, Baylor College of Medicine, Houston, Texas
| | - Sarika U Peters
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Eric D Marsh
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Di An
- Acadia Pharmaceuticals Inc, San Diego, California
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Allison K, Maletic-Savatic M, Pehlivan D. MECP2-related disorders while gene-based therapies are on the horizon. Front Genet 2024; 15:1332469. [PMID: 38410154 PMCID: PMC10895005 DOI: 10.3389/fgene.2024.1332469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/23/2024] [Indexed: 02/28/2024] Open
Abstract
The emergence of new genetic tools has led to the discovery of the genetic bases of many intellectual and developmental disabilities. This creates exciting opportunities for research and treatment development, and a few genetic disorders (e.g., spinal muscular atrophy) have recently been treated with gene-based therapies. MECP2 is found on the X chromosome and regulates the transcription of thousands of genes. Loss of MECP2 gene product leads to Rett Syndrome, a disease found primarily in females, and is characterized by developmental regression, motor dysfunction, midline hand stereotypies, autonomic nervous system dysfunction, epilepsy, scoliosis, and autistic-like behavior. Duplication of MECP2 causes MECP2 Duplication Syndrome (MDS). MDS is found mostly in males and presents with developmental delay, hypotonia, autistic features, refractory epilepsy, and recurrent respiratory infections. While these two disorders share several characteristics, their differences (e.g., affected sex, age of onset, genotype/phenotype correlations) are important to distinguish in the light of gene-based therapy because they require opposite solutions. This review explores the clinical features of both disorders and highlights these important clinical differences.
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Affiliation(s)
- Katherine Allison
- Royal College of Surgeons in Ireland, School of Medicine, Dublin, Ireland
| | - Mirjana Maletic-Savatic
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States
| | - Davut Pehlivan
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States
- Blue Bird Circle Rett Center, Texas Children's Hospital, Houston, TX, United States
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Neul JL, Benke TA, Marsh ED, Suter B, Silveira L, Fu C, Peters SU, Percy AK. Top caregiver concerns in Rett syndrome and related disorders: data from the US natural history study. J Neurodev Disord 2023; 15:33. [PMID: 37833681 PMCID: PMC10571464 DOI: 10.1186/s11689-023-09502-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
OBJECTIVE Recent advances in the understanding of neurodevelopmental disorders such as Rett syndrome (RTT) have enabled the discovery of novel therapeutic approaches that require formal clinical evaluation of efficacy. Clinical trial success depends on outcome measures that assess clinical features that are most impactful for affected individuals. To determine the top concerns in RTT and RTT-related disorders we asked caregivers to list the top caregiver concerns to guide the development and selection of appropriate clinical trial outcome measures for these disorders. METHODS Caregivers of participants enrolled in the US Natural History Study of RTT and RTT-related disorders (n = 925) were asked to identify the top 3 concerning problems impacting the affected participant. We generated a weighted list of top caregiver concerns for each of the diagnostic categories and compared results between the disorders. Further, for classic RTT, caregiver concerns were analyzed by age, clinical severity, and common RTT-causing mutations in MECP2. RESULTS The top caregiver concerns for classic RTT were effective communication, seizures, walking/balance issues, lack of hand use, and constipation. The frequency of the top caregiver concerns for classic RTT varied by age, clinical severity, and specific mutations, consistent with known variation in the frequency of clinical features across these domains. Caregivers of participants with increased seizure severity often ranked seizures as the first concern, whereas caregivers of participants without active seizures often ranked hand use or communication as the top concern. Comparison across disorders found commonalities in the top caregiver concerns between classic RTT, atypical RTT, MECP2 duplication syndrome, CDKL5 deficiency disorder, and FOXG1 syndrome; however, distinct differences in caregiver concerns between these disorders are consistent with the relative prevalence and impact of specific clinical features. CONCLUSION The top caregiver concerns for individuals with RTT and RTT-related disorders reflect the impact of the primary clinical symptoms of these disorders. This work is critical in the development of meaningful therapies, as optimal therapy should address these concerns. Further, outcome measures to be utilized in clinical trials should assess these clinical issues identified as most concerning by caregivers.
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Affiliation(s)
- Jeffrey L Neul
- Department of Pediatrics, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Timothy A Benke
- University of Colorado School of Medicine/Children's Hospital Colorado, Aurora, CO, USA
| | - Eric D Marsh
- Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | | | - Lori Silveira
- University of Colorado School of Medicine/Children's Hospital Colorado, Aurora, CO, USA
| | - Cary Fu
- Department of Pediatrics, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sarika U Peters
- Department of Pediatrics, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alan K Percy
- University of Alabama at Birmingham, Birmingham, AL, USA
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Neul JL, Benke TA, Marsh ED, Lane JB, Lieberman DN, Skinner SA, Glaze DG, Suter B, Heydemann PT, Beisang AA, Standridge SM, Ryther RCC, Haas RH, Edwards LJ, Ananth A, Percy AK. Distribution of hand function by age in individuals with Rett syndrome. ANNALS OF THE CHILD NEUROLOGY SOCIETY 2023; 1:228-238. [PMID: 38496825 PMCID: PMC10939125 DOI: 10.1002/cns3.20038] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/14/2023] [Indexed: 03/19/2024]
Abstract
Objective To determine the longitudinal distribution of hand function skills in individuals with classic Rett Syndrome (RTT), an X-linked dominant neurodevelopmental disorder, and correlate with MECP2 variants. Method We conducted a longitudinal study of 946 girls and young women with typical RTT seen between 2006 and 2021 in the US Natural History Study (NHS) featuring a structured clinical evaluation to assess the level of hand function skills. The specific focus in this study was to assess longitudinal variation of hand skills from age 2 through age 18 years in relation to specific MECP2 variant groups. Results Following the initial regression period, hand function continues to decline across the age spectrum in individuals with RTT. Specific differences are noted with steeper declines in hand function among those with milder variants (Group A: R133C, R294X, R306C, and C-terminal truncations) compared to groups composed of individuals with more severe variants. Conclusions These temporal variations in hand use represent specific considerations which could influence the design of clinical trials that test therapies aiming to ameliorate specific functional limitations in individuals with RTT. Furthermore, the distinct impact of specific MECP2 variants on clinical severity, especially related to hand use, should be considered in such interventional trials.
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Affiliation(s)
| | - Tim A. Benke
- University of Colorado, School of Medicine, Children’s Hospital Colorado, Aurora, CO
| | - Eric D. Marsh
- Children’s Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Jane B. Lane
- University of Alabama at Birmingham, Birmingham, AL
| | | | | | | | | | | | | | | | | | | | - Lloyd J. Edwards
- University of Alabama at Birmingham, School of Public Health, Birmingham, AL
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Percy AK, Neul JL, Benke TA, Marsh ED, Glaze DG. A review of the Rett Syndrome Behaviour Questionnaire and its utilization in the assessment of symptoms associated with Rett syndrome. Front Pediatr 2023; 11:1229553. [PMID: 37635789 PMCID: PMC10450502 DOI: 10.3389/fped.2023.1229553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/03/2023] [Indexed: 08/29/2023] Open
Abstract
The Rett Syndrome Behaviour Questionnaire (RSBQ), which is completed by the caregiver, is one of the most widely used efficacy measures in clinical studies of Rett syndrome (RTT) due to its specificity to the core features of RTT. As healthcare providers participate in routine healthcare assessments of individuals with RTT in clinical practice, there is a need for these providers to understand the psychometric properties of the RSBQ and how it relates to the core clinical features of RTT. Here, we describe the characteristics of the RSBQ, review the literature on its validity and reliability as well as its performance in a phase 2 study and the recent phase 3 LAVENDER study. The RSBQ was first shown to discriminate RTT from other intellectual disorders with good inter-rater and test-retest reliability scores. It was subsequently validated as an appropriate instrument for measuring behavior in females with RTT and adopted as a clinical trial outcome. In LAVENDER, the FDA-approved drug trofinetide significantly improved the RSBQ total score over placebo in girls and women with RTT and change from baseline for all RSBQ subscores were directionally in favor of trofinetide. The change in RSBQ was aligned with the Clinical Global Impression-Improvement scale, suggesting that improvement in behavioral components may be related to overall clinical status. Given its validity and ubiquity in RTT clinical studies, it is important that the interplay of the domains and the psychometric profile of the RSBQ are understood.
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Affiliation(s)
- Alan K. Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jeffrey L. Neul
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Timothy A. Benke
- Children’s Hospital of Colorado/University of Colorado School of Medicine, Aurora, CO, United States
| | - Eric D. Marsh
- Department of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Daniel G. Glaze
- Texas Children’s Hospital/Baylor College of Medicine, Houston, TX, United States
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Hirano D, Goto Y, Shoji H, Taniguchi T. Relationship between hand stereotypies and purposeful hand use and factors causing skin injuries and joint contractures in individuals with Rett syndrome. Early Hum Dev 2023; 183:105821. [PMID: 37429197 DOI: 10.1016/j.earlhumdev.2023.105821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/06/2023] [Accepted: 07/06/2023] [Indexed: 07/12/2023]
Abstract
BACKGROUND Skin injuries and joint contractures in the upper limbs are observed in approximately 50 % of individuals with Rett syndrome, respectively. AIMS To investigate the relationship between stereotypic hand movements and purposeful hand skills, items related to these, and factors that cause upper extremity skin injuries and joint contractures in individuals with Rett syndrome. STUDY DESIGN We conducted a cross-sectional observational study in 2020 with families belonging to either of the two largest Rett syndrome organizations in Japan. SUBJECTS In 2020, we sent a questionnaire to 194 Japanese families. OUTCOME MEASURES We used descriptive statistics to indicate frequency in each question. We analysed the association between hand stereotypies and purposeful hand use, their associations with each questionnaire item, and the relationship between the occurrence of skin injuries and joint contractures. RESULTS We acquired information from 72 cases. We found correlations between stereotypy frequency with reaching and between purposeful hand use with intellectual development grade and hand function. Hand and finger skin injuries and elbow and finger joint contractures were associated with wringing/washing, grasping, locomotion, reaching, and intellectual development grade. We identified cut-off points for the occurrence of elbow and finger joint contractures of 10 years 6 months, ability to roll over, finger feeds only, and understanding of simple words. CONCLUSIONS Direct interventions can reduce hand stereotypies and increase purposeful hand use, while related items can be addressed with indirect interventions. Evaluations of factors that cause skin injuries and joint contractures can prevent their occurrence.
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Affiliation(s)
- Daisuke Hirano
- Graduate School of Health and Welfare Sciences, International University of Health and Welfare, 4-1-26 Akasaka, Minato, Tokyo 107-8402, Japan; Department of Occupational Therapy, School of Health Sciences, International University of Health and Welfare, 2600-1 Kitakanemaru, Otawara, Tochigi 324-8501, Japan.
| | - Yoshinobu Goto
- Graduate School of Health and Welfare Sciences, International University of Health and Welfare, 4-1-26 Akasaka, Minato, Tokyo 107-8402, Japan; Department of Physiology, Faculty of Medicine, School of Medicine, International University of Health and Welfare, 4-3 Kozunomori, Narita, Chiba 286-8686, Japan; Department of Occupational Therapy, School of Health Sciences at Fukuoka, International University of Health and Welfare, 137-1 Enokizu, Okawa, Fukuoka 831-8501, Japan
| | - Hiroaki Shoji
- Laboratory of Physiology, College of Education, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
| | - Takamichi Taniguchi
- Graduate School of Health and Welfare Sciences, International University of Health and Welfare, 4-1-26 Akasaka, Minato, Tokyo 107-8402, Japan; Department of Occupational Therapy, School of Health Sciences at Narita, International University of Health and Welfare, 4-3 Kozunomori, Narita, Chiba 286-8686, Japan
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Neul JL, Percy AK, Benke TA, Berry-Kravis EM, Glaze DG, Marsh ED, Lin T, Stankovic S, Bishop KM, Youakim JM. Trofinetide for the treatment of Rett syndrome: a randomized phase 3 study. Nat Med 2023; 29:1468-1475. [PMID: 37291210 PMCID: PMC10287558 DOI: 10.1038/s41591-023-02398-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 05/12/2023] [Indexed: 06/10/2023]
Abstract
Rett syndrome is a rare, genetic neurodevelopmental disorder. Trofinetide is a synthetic analog of glycine-proline-glutamate, the N-terminal tripeptide of the insulin-like growth factor 1 protein, and has demonstrated clinical benefit in phase 2 studies in Rett syndrome. In this phase 3 study ( https://clinicaltrials.gov identifier NCT04181723 ), females with Rett syndrome received twice-daily oral trofinetide (n = 93) or placebo (n = 94) for 12 weeks. For the coprimary efficacy endpoints, least squares mean (LSM) change from baseline to week 12 in the Rett Syndrome Behaviour Questionnaire for trofinetide versus placebo was -4.9 versus -1.7 (P = 0.0175; Cohen's d effect size, 0.37), and LSM Clinical Global Impression-Improvement at week 12 was 3.5 versus 3.8 (P = 0.0030; effect size, 0.47). For the key secondary efficacy endpoint, LSM change from baseline to week 12 in the Communication and Symbolic Behavior Scales Developmental Profile Infant-Toddler Checklist Social Composite score was -0.1 versus -1.1 (P = 0.0064; effect size, 0.43). Common treatment-emergent adverse events included diarrhea (80.6% for trofinetide versus 19.1% for placebo), which was mostly mild to moderate in severity. Significant improvement for trofinetide compared with placebo was observed for the coprimary efficacy endpoints, suggesting that trofinetide provides benefit in treating the core symptoms of Rett syndrome.
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Affiliation(s)
- Jeffrey L Neul
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alan K Percy
- University of Alabama at Birmingham, Birmingham, AL, USA
| | - Timothy A Benke
- Children's Hospital of Colorado and University of Colorado School of Medicine, Aurora, CO, USA
| | | | - Daniel G Glaze
- Texas Children's Hospital and Baylor College of Medicine, Houston, TX, USA
| | - Eric D Marsh
- Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Tim Lin
- Acadia Pharmaceuticals Inc., San Diego, CA, USA
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Neul JL, Benke TA, Marsh ED, Suter B, Silveira L, Fu C, Peters SU, Percy AK. Top Caregiver Concerns in Rett syndrome and related disorders: data from the US Natural History Study. RESEARCH SQUARE 2023:rs.3.rs-2566253. [PMID: 36993737 PMCID: PMC10055548 DOI: 10.21203/rs.3.rs-2566253/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Objective Recent advances in the understanding of neurodevelopmental disorders such as Rett syndrome (RTT) has enabled development of novel therapeutic approaches that are currently undergoing clinical evaluation or are proposed to move into clinical development. Clinical trial success depends on outcome measures that assess clinical features that are most impactful for affected individuals. To determine the top concerns in RTT and RTT-related disorders we asked caregivers to list the top clinical concerns in order to gain information to guide the development and selection of outcome measures for future clinical trials. Methods Caregivers of participants enrolled in the US Natural History Study of RTT and related disorders were asked to identify the top 3 concerning problems impacting the affected participant. We generated a weighted list of top caregiver concerns for each of the diagnostic categories and compared results between the disorders. Further, for Classic RTT, caregiver concerns were analyzed by age, clinical severity, and common RTT-causing mutations in MECP2. Results The top caregiver concerns for Classic RTT were effective communication, seizures, walking/balance issues, lack of hand use, and constipation. The rank order of the frequency of the top caregiver concerns for Classic RTT varied by age, clinical severity, and specific mutations, consistent with known variation in the frequency of clinical features across these domains. The frequency of caregiver concern for seizures, hand use, and spoken language increased in relation to clinician assessed severity in these clinical domains, showing consistency between clinician assessments and caregiver concerns. Comparison across disorders found commonalities in the top caregiver concerns between Classic RTT, Atypical RTT, MECP2 Duplication Syndrome, CDKL5 Deficiency Disorder, and FOXG1 Syndrome; however, distinct differences in caregiver concerns between these disorders are consistent with the relative prevalence and impact of specific clinical features. Conclusion The top caregiver concerns for individuals with RTT and the RTT-related disorders reflect the impact of the primary clinical symptoms of these disorders. This work is critical in the development of meaningful therapies, as optimal therapy should address these concerns. Further, outcome measures to be utilized in clinical trials should assess these clinical issues identified as most concerning by caregivers.
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Affiliation(s)
| | - Timothy A Benke
- University of Colorado School of Medicine: University of Colorado Anschutz Medical Campus School of Medicine
| | | | | | - Lori Silveira
- University of Colorado School of Medicine: University of Colorado Anschutz Medical Campus School of Medicine
| | - Cary Fu
- Vanderbilt University Medical Center
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Politano D, Gana S, Pezzotti E, Berardinelli A, Pasca L, Carmen Barbero V, Pichiecchio A, Maria Valente E, Errichiello E. A novel variant in NEUROD2 in a patient with Rett-like phenotype points to Glu130 codon as a mutational hotspot. Brain Dev 2023; 45:179-184. [PMID: 36446697 DOI: 10.1016/j.braindev.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/25/2022] [Accepted: 11/14/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND NEUROD2, encoding the neurogenic differentiation factor 2, is essential for neurodevelopment. To date, heterozygous missense variants in this gene have been identified in eight patients (from six unrelated families) with epileptic encephalopathy and developmental delay. CASE REPORT We describe a child with initial clinical suspicion of Rett/Rett-like syndrome, in whom exome sequencing detected a novel de novo variant (c.388G > A, p.Glu130Lys) in NEUROD2. Interestingly, a missense change affecting the same codon, c.388G > C (p.Glu130Gln), was previously identified in other two patients. CONCLUSIONS Our results suggest that Glu130 might represent a potential mutational hotspot of NEUROD2. Furthermore, the clinical findings (especially the absence of clinically overt seizures) strengthen the NEUROD2-phenotypic spectrum, implying that developmental delay may also manifest isolatedly. We suggest inclusion of NEUROD2-associated developmental and epileptic encephalopathies (DEEs) in the differential diagnosis of atypical Rett syndrome as well as gene panels related to autism spectrum disorder.
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Affiliation(s)
- Davide Politano
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Simone Gana
- Medical Genetics Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Elena Pezzotti
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Angela Berardinelli
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, Pavia, Italy
| | - Ludovica Pasca
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy; Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, Pavia, Italy
| | | | - Anna Pichiecchio
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy; Department of Neuroradiology, Advanced Imaging and Radiomics Center, IRCCS Mondino Foundation, Pavia, Italy
| | - Enza Maria Valente
- Medical Genetics Unit, IRCCS Mondino Foundation, Pavia, Italy; Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Edoardo Errichiello
- Medical Genetics Unit, IRCCS Mondino Foundation, Pavia, Italy; Department of Molecular Medicine, University of Pavia, Pavia, Italy.
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Nilles C, Amorelli G, Pringsheim TM, Martino D. "Unvoluntary" Movement Disorders: Distinguishing between Tics, Akathisia, Restless Legs, and Stereotypies. Semin Neurol 2023; 43:123-146. [PMID: 36854394 DOI: 10.1055/s-0043-1764164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Tics, stereotypies, akathisia, and restless legs fall at different places on the spectrum of discrete, unwanted and potentially disabling motor routines. Unlike tremor, chorea, myoclonus, or dystonia, this subgroup of abnormal movements is characterized by the subject's variable ability to inhibit or release undesired motor patterns on demand. Though it may be sometimes clinically challenging, it is crucial to distinguish these "unvoluntary" motor behaviors because secondary causes and management approaches differ substantially. To this end, physicians must consider the degree of repetitiveness of the movements, the existence of volitional control, and the association with sensory symptoms, or cognitive-ideational antecedent. This review aims to summarize the current existing knowledge on phenomenology, diagnosis, and treatment of tics, stereotypies, akathisia, and restless leg syndrome.
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Affiliation(s)
- Christelle Nilles
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Gabriel Amorelli
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Tamara M Pringsheim
- Department of Clinical Neurosciences, Psychiatry, Pediatrics and Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.,Mathison Centre for Mental Health Research and Education, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Davide Martino
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Mathison Centre for Mental Health Research and Education, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
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Melo C, Ribeiro TP, Prior C, Gesta C, Martins V, Oliveira G, Temudo T. Motor stereotypies in autism spectrum disorder: Clinical randomized study and classification proposal. AUTISM : THE INTERNATIONAL JOURNAL OF RESEARCH AND PRACTICE 2023; 27:456-471. [PMID: 35762643 DOI: 10.1177/13623613221105479] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
LAY ABSTRACT Motor stereotypies are one of the most frequent features in children with a diagnosis of autism spectrum disorder. They may disrupt children's functioning and development and be a potential source of stress for families. Several factors, including sex, age, cognitive ability, and severity of autism spectrum disorder, may influence the presence and intensity of stereotypies. The present study aimed to identify the prevalence of motor stereotypies in a group of children with autism spectrum disorder. In addition, it sought to investigate whether sex, age, cognitive ability, verbal language, neurological comorbidities, and severity of autism spectrum disorder were associated with an increased probability and higher number, duration, and variability of stereotypies. A total of 134 participants aged 2.3-17.6 years underwent a clinical protocol with standardized video-recorded sessions. Stereotypies were identified and classified by two independent evaluators. The prevalence of stereotypies was 56.7%, and a total of 1198 motor stereotypies were captured. Children who were younger, nonverbal, and had higher severity of autism spectrum disorder had an increased probability of presenting stereotypies. Being nonverbal or having higher severity of autism spectrum disorder was also associated with presenting a higher number of stereotypies. Children with developmental delay, intellectual disability, or epilepsy displayed longer stereotypies, and children with developmental delay or intellectual disability additionally presented more diverse stereotypies. As part of the study, the authors present a clinical classification model, a glossary, and video samples of motor stereotypies. The findings of this study suggest that children who are younger, nonverbal, have lower cognitive ability, and have higher severity of autism spectrum disorder may have a higher burden of stereotypies. Earlier intervention and monitoring of these children have the potential to improve their long-term outcomes.
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Affiliation(s)
- Cláudia Melo
- Centro Hospitalar do São João, Portugal.,University of Porto, Portugal
| | - Tiago Pinto Ribeiro
- Centro Hospitalar Universitário do Porto, Portugal.,PIN-Progresso infantil, Portugal
| | | | - Camila Gesta
- Centro Hospitalar Universitário do Porto, Portugal
| | | | - Guiomar Oliveira
- Centro Hospitalar e Universitário de Coimbra, Portugal.,University of Coimbra, Portugal
| | - Teresa Temudo
- Centro Hospitalar Universitário do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar, Portugal
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Ak M, Suter B, Akturk Z, Harris H, Bowyer K, Mignon L, Pasupuleti S, Glaze DG, Pehlivan D. Exploring the characteristics and most bothersome symptoms in MECP2 duplication syndrome to pave the path toward developing parent-oriented outcome measures. Mol Genet Genomic Med 2022; 10:e1989. [PMID: 35702943 PMCID: PMC9356562 DOI: 10.1002/mgg3.1989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/01/2022] [Accepted: 05/13/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND MECP2 Duplication Syndrome (MDS), resulting from the duplication of Xq28 region, including MECP2, is a rare disorder with a nascent understanding in clinical features and severity. Studies using antisense oligonucleotides revealed a broad phenotypic rescue in transgenic mice. With human clinical trials on the horizon, there is a need to develop clinical outcome measures for MDS. METHODS We surveyed caregivers of MDS individuals to explore the frequency and severity of MDS clinical features, and identify the most meaningful symptoms/domains that need to be included in the outcome measure scales. RESULTS A total of 101 responses were eligible for the survey. The top six most meaningful symptoms to caregivers in descending order included epilepsy, gross motor, fine motor, communication, infection, and constipation problems. Epilepsy was present in 58.4% of the subjects and 75% were drug-resistant, Furthermore, ~12% required intensive care unit (ICU) admission. Infections were present in 55% of the subjects, and one-fourth of them required ICU admission. Constipation was present in ~85% of the subjects and one-third required enemas/suppositories. CONCLUSION Our study is one of the largest cohorts conducted on MDS individuals characterizing the frequency and severity of MDS symptoms. Additionally, these study results will contribute to establishing a foundation to develop parent-reported outcomes in MDS.
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Affiliation(s)
- Muharrem Ak
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Bernhard Suter
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Blue Bird Circle Rett Center, Texas Children's Hospital, Houston, Texas, USA
| | - Zekeriya Akturk
- Institute of General Practice and Health Services Research, School of Medicine, Technical University of Munich, Munich, Germany
| | - Holly Harris
- The Meyer Center for Developmental Pediatrics, Houston, Texas, USA
| | | | | | - Sasidhar Pasupuleti
- Bioinformatics Core, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
| | - Daniel G Glaze
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Blue Bird Circle Rett Center, Texas Children's Hospital, Houston, Texas, USA
| | - Davut Pehlivan
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Blue Bird Circle Rett Center, Texas Children's Hospital, Houston, Texas, USA
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14
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Ramirez JM, Karlen-Amarante M, Wang JDJ, Huff A, Burgraff N. Breathing disturbances in Rett syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2022; 189:139-151. [PMID: 36031301 PMCID: PMC10029146 DOI: 10.1016/b978-0-323-91532-8.00018-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Rett Syndrome is an X-linked neurological disorder characterized by behavioral and neurological regression, seizures, motor deficits, and dysautonomia. A particularly prominent presentation includes breathing abnormalities characterized by breathing irregularities, hyperventilation, repetitive breathholding during wakefulness, obstructive and central apneas during sleep, and abnormal responses to hypoxia and hypercapnia. The condition and pathology of the respiratory system is further complicated by dysfunctions of breathing-motor coordination, which is reflected in dysphagia. The discovery of the X-linked mutations in the MECP2 gene has transformed our understanding of the cellular and molecular mechanisms that are at the root of various clinical phenotypes. However, the genotype-phenotype relationship is complicated by various factors which include not only X-inactivation but also consequences of the intermittent hypoxia and oxidative stress associated with the breathing abnormalities.
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Affiliation(s)
- Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States; Department of Neurological Surgery, University of Washington School of Medicine, Seattle, WA, United States.
| | - Marlusa Karlen-Amarante
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Jia-Der Ju Wang
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Alyssa Huff
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States
| | - Nicholas Burgraff
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, United States
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15
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Hirano D, Goto Y, Shoji H, Taniguchi T. Comparison of the presence and absence of an intervention to reduce hand stereotypies in individuals with Rett syndrome. JOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES 2021; 35:607-622. [PMID: 34962025 DOI: 10.1111/jar.12973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 11/29/2021] [Accepted: 12/10/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND We investigated how many individuals with Rett syndrome were undergoing interventions to reduce stereotypic hand movements and the factors determining the presence or absence of an intervention. METHOD A questionnaire was sent to 194 families. Each survey item was compared between the intervention and non-intervention groups according to the presence or absence of interventions to reduce hand stereotypies. RESULTS Information was acquired from 72 cases; 72.1% of individuals had received an intervention to reduce stereotypies at some point in their lives. An upper limb splint was the most common intervention. Age, locomotor and reaching function, diagnostic age, frequency and type of stereotypy, joint contractures and stereotypy-associated problems separated the presence or absence of a current or past intervention. CONCLUSIONS Interventions for stereotypy-associated problems are important and there are several variables related to whether an intervention is received.
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Affiliation(s)
- Daisuke Hirano
- Graduate School of Health and Welfare Sciences, International University of Health and Welfare, Tokyo, Japan.,Department of Occupational Therapy, School of Health Sciences, International University of Health and Welfare, Otawara, Japan
| | - Yoshinobu Goto
- Graduate School of Health and Welfare Sciences, International University of Health and Welfare, Tokyo, Japan.,Faculty of Medicine, School of Medicine, International University of Health and Welfare, Chiba, Japan.,Department of Occupational Therapy, School of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan
| | - Hiroaki Shoji
- Laboratory of Physiology, College of Education, Ibaraki University, Ibaraki, Japan
| | - Takamichi Taniguchi
- Graduate School of Health and Welfare Sciences, International University of Health and Welfare, Tokyo, Japan.,Department of Occupational Therapy, School of Health Sciences, International University of Health and Welfare, Otawara, Japan
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16
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Singh J, Lanzarini E, Nardocci N, Santosh P. Movement disorders in patients with Rett syndrome: A systematic review of evidence and associated clinical considerations. Psychiatry Clin Neurosci 2021; 75:369-393. [PMID: 34472659 PMCID: PMC9298304 DOI: 10.1111/pcn.13299] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/28/2021] [Accepted: 08/20/2021] [Indexed: 12/18/2022]
Abstract
AIM This systematic review identified and thematically appraised clinical evidence of movement disorders in patients with Rett syndrome (RTT). METHOD Using PRISMA criteria, six electronic databases were searched from inception to April 2021. A thematic analysis was then undertaken on the extracted data to identify potential themes. RESULTS Following the thematic analysis, six themes emerged: (i) clinical features of abnormal movement behaviors; (ii) mutational profile and its impact on movement disorders; (iii) symptoms and stressors that impact on movement disorders; (iv) possible underlying neurobiological mechanisms; (v) quality of life and movement disorders; and (vi) treatment of movement disorders. Current guidelines for managing movement disorders in general were then reviewed to provide possible treatment recommendations for RTT. CONCLUSION Our study offers an enriched data set for clinical investigations and treatment of fine and gross motor issues in RTT. A detailed understanding of genotype-phenotype relationships of movement disorders allows for more robust genetic counseling for families but can also assist healthcare professionals in terms of monitoring disease progression in RTT. The synthesis also showed that environmental enrichment would be beneficial for improving some aspects of movement disorders. The cerebellum, basal ganglia, alongside dysregulation of the cortico-basal ganglia-thalamo-cortical loop, are likely anatomical targets. A review of treatments for movement disorders also helped to provide recommendations for treating and managing movement disorders in patients with RTT.
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Affiliation(s)
- Jatinder Singh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London and Maudsley NHS Foundation Trust, London, UK.,Centre for Personalised Medicine in Rett Syndrome, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Evamaria Lanzarini
- Child and Adolescent Neuropsychiatry Unit, Infermi Hospital, Rimini, Italy
| | - Nardo Nardocci
- Department of Paediatric Neurology, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Paramala Santosh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London and Maudsley NHS Foundation Trust, London, UK.,Centre for Personalised Medicine in Rett Syndrome, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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17
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Downs J, Wong K, Drummond C, Leonard H. Longitudinal Evaluation of the Stability of Hand Function in Rett Syndrome. J Pediatr 2021; 237:244-249.e3. [PMID: 34214590 DOI: 10.1016/j.jpeds.2021.06.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/20/2021] [Accepted: 06/23/2021] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To investigate the longitudinal stability of hand function in Rett syndrome and to analyze further the relationships between stability of hand function and genotype, age, and walking ability. STUDY DESIGN Longitudinal video data of functional abilities of individuals with genetically confirmed Rett syndrome were collected by families of individuals registered with the Australian Rett Syndrome Database. A total of 120 individuals provided 290 recordings from which 170 observation pairs were available for comparison. The Rett Syndrome Hand Function Scale was used to classify a level of hand function observed in each video on a range from unable to grasp, pick up, and hold objects to skillful manipulation of large and small objects. RESULTS Approximately one-third of the population lost some hand function over time. Younger children (<6 years) rather than adults were at greater risk of deterioration in hand function. Clinical severity, as indicated by walking ability or genotype, played a lesser role. There was no identified pattern between genotype and the stability of hand function skills. Rather, mutations associated with milder (p.Arg133Cys, p.Arg294∗) and greater (p.Arg106Trp, p.Thr158Met) clinical severity were both associated with greater risks of decline. CONCLUSIONS Genotype was a lesser predictor of loss of hand function beyond the early regression period, and younger children were particularly vulnerable to further loss of hand function compared with adults.
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Affiliation(s)
- Jenny Downs
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Australia; Curtin School of Allied Health, Curtin University, Perth, Australia.
| | - Kingsley Wong
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Australia
| | - Carolyn Drummond
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Australia; Children's Neuroscience Service, Department of Neurology, Perth Children's Hospital, Perth, Australia
| | - Helen Leonard
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, Australia
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18
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Unraveling Molecular Pathways Altered in MeCP2-Related Syndromes, in the Search for New Potential Avenues for Therapy. Biomedicines 2021; 9:biomedicines9020148. [PMID: 33546327 PMCID: PMC7913493 DOI: 10.3390/biomedicines9020148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/25/2021] [Accepted: 01/30/2021] [Indexed: 12/27/2022] Open
Abstract
Methyl-CpG-binding protein 2 (MeCP2) is an X-linked epigenetic modulator whose dosage is critical for neural development and function. Loss-of-function mutations in MECP2 cause Rett Syndrome (RTT, OMIM #312750) while duplications in the Xq28 locus containing MECP2 and Interleukin-1 receptor-associated kinase 1 (IRAK1) cause MECP2 duplication syndrome (MDS, OMIM #300260). Both are rare neurodevelopmental disorders that share clinical symptoms, including intellectual disability, loss of speech, hand stereotypies, vasomotor deficits and seizures. The main objective of this exploratory study is to identify novel signaling pathways and potential quantitative biomarkers that could aid early diagnosis and/or the monitoring of disease progression in clinical trials. We analyzed by RT-PCR gene expression in whole blood and microRNA (miRNA) expression in plasma, in a cohort of 20 females with Rett syndrome, 2 males with MECP2 duplication syndrome and 28 healthy controls, and correlated RNA expression with disease and clinical parameters. We have identified a set of potential biomarker panels for RTT diagnostic and disease stratification of patients with microcephaly and vasomotor deficits. Our study sets the basis for larger studies leading to the identification of specific miRNA signatures for early RTT detection, stratification, disease progression and segregation from other neurodevelopmental disorders. Nevertheless, these data will require verification and validation in further studies with larger sample size including a whole range of ages.
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19
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Song N, Duan C, Li Y, Qian TX, Wang Q, Zhao W, Wang XY. Induction of long-term potentiation at Schaffer collateral-CA1 synapses in mice hippocampus after IMPX977 administration. CHINESE HERBAL MEDICINES 2021; 13:131-135. [PMID: 36117761 PMCID: PMC9476771 DOI: 10.1016/j.chmed.2020.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/20/2020] [Accepted: 05/27/2020] [Indexed: 11/22/2022] Open
Abstract
Objective To investigate the effects of IMPX977 on long term potentiation (LTP) at Schaffer collateral-CA1 synapses in vitro and on methyl CpG binding protein 2 (Mecp2) expression in mice cortex and hippocampus. Methods Thirty-two C57BL/6 mice were randomly divided into four groups: control, olive oil (vehicle), IMPX977 low (5 mg/kg) and high (15 mg/kg) groups. Mice were administrated every other day orally for two weeks. Extracellular recording technique in vitro was used to record the effects of IMPX977 on Schaffer collateral-CA1 LTP pathway in acute mice hippocampal slices. The Mecp2 protein expression level was detected by Western blotting. Results Compared to the control group, vehicle did not alter the synaptic transmission in Schaffer collateral-CA1 synapses, however, IMPX977 at concentrations of 5 mg/kg and 15 mg/kg significantly enhanced fEPSP (field excitatory postsynaptic potential) slope in Schaffer collateral-CA1 pathway to (179.6 ± 17.8)% and (191.4 ± 21.4)%, individually 60 min after HFS, IMPX977 improved LTP induction significantly at Schaffer collateral-CA1 pathway at least. Also, IMPX977 significantly elevated MeCP2 protein level in cortex. Conclusion The effects of IMPX977 on synaptic transmission and Mecp2 protein expression provided convincing evidence that IMPX977 could be promising new drug candidates for Rett syndrome treatment.
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20
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Kano K, Yamanaka G, Muramatsu K, Morichi S, Ishida Y, Takamatsu T, Suzuki S, Miyajima T, Nakagawa E, Nishino I, Kawashima H. Beta-propeller protein-associated neurodegeneration presenting Rett-like features: A case report and literature review. Am J Med Genet A 2020; 185:579-583. [PMID: 33251766 DOI: 10.1002/ajmg.a.61993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/25/2020] [Accepted: 10/28/2020] [Indexed: 01/07/2023]
Abstract
Several patients with beta-propeller protein-associated neurodegeneration (BPAN)/static encephalopathy with neurodegeneration in adulthood have been reported to present Rett syndrome (RTT)-like features. This report presents an individual with BPAN showing clinical features of RTT. Psychomotor delay and epilepsy onset were noted at 1 year, and regression began at 4 years. Screening of the methyl-CpG binding protein 2 (MECP2) did not show variants. At 22 years, basal ganglia iron deposits were found on magnetic resonance imaging (MRI), and the WD-domain repeat 45 gene (WDR45) variant was identified. Review of the literature showed that BPAN with RTT-like features is associated with more epileptic seizures and less deceleration of head growth, breathing irregularities, and cold extremities than classic RTT with MECP2 variants. These clinical presentations may provide clues for differentiating between these two disorders. However, both WDR45 and MECP2 should be screened in patients presenting a clinical picture of RTT without specific MRI findings of BPAN.
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Affiliation(s)
- Kanako Kano
- Division of Pediatrics and Adolescent Medicine, Tokyo Medical University, Tokyo, Japan
| | - Gaku Yamanaka
- Division of Pediatrics and Adolescent Medicine, Tokyo Medical University, Tokyo, Japan
| | | | - Shinichiro Morichi
- Division of Pediatrics and Adolescent Medicine, Tokyo Medical University, Tokyo, Japan
| | - Yu Ishida
- Division of Pediatrics and Adolescent Medicine, Tokyo Medical University, Tokyo, Japan
| | - Tomoko Takamatsu
- Division of Pediatrics and Adolescent Medicine, Tokyo Medical University, Tokyo, Japan
| | - Shinji Suzuki
- Division of Pediatrics and Adolescent Medicine, Tokyo Medical University, Tokyo, Japan
| | - Tasuku Miyajima
- Division of Pediatrics and Adolescent Medicine, Tokyo Medical University, Tokyo, Japan
| | - Eiji Nakagawa
- Department of Child Neurology, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Hisashi Kawashima
- Division of Pediatrics and Adolescent Medicine, Tokyo Medical University, Tokyo, Japan
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21
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Young DR, Suter B, Levine JT, Glaze DG, Layne CS. Characteristic behaviors associated with gait of individuals with Rett syndrome. Disabil Rehabil 2020; 44:1508-1515. [PMID: 32931336 DOI: 10.1080/09638288.2020.1820084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Individuals with Rett syndrome (RTT) exhibit impaired motor performance and gait performance, leading to decreased quality of life. Currently, there is no robust observational instrument to identify gait characteristics in RTT. Current scales are limited as individuals with intellectual disorders may be unable to understand instructions. Our primary purpose was to utilize video analysis to characterize the behaviors associated with walking in individuals with RTT and explore the relationship between behaviors during overground and during treadmill walking. METHODS Fourteen independently ambulatory females with RTT were video-taped and observed during overground and treadmill walking. Their gait was codified into an observational checklist to reveal prominent features associated with gait in this population. RESULTS Participants exhibited similar rates of freezing, veering, and hand stereotypies between overground and treadmill walking; however, freeze duration was shortened during treadmill walking. Toe walking was prominently exhibited during overground, but not treadmill walking. During both walking modes, participants required extensive external motivation to maintain their walking patterns. CONCLUSIONS Results identify several gait characteristics observable during overground and treadmill walking. In general, participants behaved similarly during overground and treadmill walking. We conclude that both overground and treadmill walking are appropriate tools to evaluate gait in this population.Implications for rehabilitationLocomotor rehabilitation may increase the quantity of walking performed by the patients, which can alleviate negative effects of the sedentary lifestyle commonly observed in patients with Rett syndrome (RTT).Video analysis of natural walking can be an effective tool to characterize gait in patients with RTT which does not require particular instructions which may not be fully understood.Both overground and treadmill walking are appropriate means of evaluating gait in individuals with RTT.
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Affiliation(s)
- David R Young
- Department of Health and Human Performance, University of Houston, Houston, TX, USA.,Center for Neuromotor and Biomechanics Research, University of Houston, Houston, TX, USA
| | - Bernhard Suter
- Blue Bird Circle Rett Center, Texas Children's Hospital, Houston, TX, USA.,Baylor College of Medicine, Houston, TX, USA
| | - Jackson T Levine
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Daniel G Glaze
- Blue Bird Circle Rett Center, Texas Children's Hospital, Houston, TX, USA.,Baylor College of Medicine, Houston, TX, USA
| | - Charles S Layne
- Department of Health and Human Performance, University of Houston, Houston, TX, USA.,Center for Neuromotor and Biomechanics Research, University of Houston, Houston, TX, USA.,Center for Neuro-Engineering and Cognitive Science, University of Houston, Houston, TX, USA
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22
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Sandweiss AJ, Brandt VL, Zoghbi HY. Advances in understanding of Rett syndrome and MECP2 duplication syndrome: prospects for future therapies. Lancet Neurol 2020; 19:689-698. [PMID: 32702338 DOI: 10.1016/s1474-4422(20)30217-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 05/07/2020] [Accepted: 05/12/2020] [Indexed: 01/07/2023]
Abstract
The X-linked gene encoding MECP2 is involved in two severe and complex neurodevelopmental disorders. Loss of function of the MeCP2 protein underlies Rett syndrome, whereas duplications of the MECP2 locus cause MECP2 duplication syndrome. Research on the mechanisms by which MeCP2 exerts effects on gene expression in neurons, studies of animal models bearing different disease-causing mutations, and more in-depth observations of clinical presentations have clarified some issues even as they have raised further questions. Yet there is enough evidence so far to suggest possible approaches to therapy for these two diseases that could go beyond attempting to address specific signs and symptoms (of which there are many) and instead target the pathophysiology underlying MECP2 disorders. Further work could bring antisense oligonucleotides, deep brain stimulation, and gene therapy into the clinic within the next decade or so.
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Affiliation(s)
- Alexander J Sandweiss
- Department of Pediatrics, Section of Neurology and Developmental Neurosciences, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA
| | - Vicky L Brandt
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA
| | - Huda Y Zoghbi
- Department of Pediatrics, Section of Neurology and Developmental Neurosciences, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA.
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23
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Abstract
Researchers from the Rett Syndrome Natural History Study (RNHS) present longitudinal data across the United States of America aimed to characterize hand stereotypies (HS) in this large cohort of patients with Rett syndrome.
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Affiliation(s)
- Matheus G Ferreira
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil
| | - Hélio A G Teive
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil
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24
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Kaufmann WE, Sprouse J, Rebowe N, Hanania T, Klamer D, Missling CU. ANAVEX®2-73 (blarcamesine), a Sigma-1 receptor agonist, ameliorates neurologic impairments in a mouse model of Rett syndrome. Pharmacol Biochem Behav 2019; 187:172796. [PMID: 31704481 DOI: 10.1016/j.pbb.2019.172796] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/26/2019] [Accepted: 10/04/2019] [Indexed: 11/23/2022]
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder that is associated in most cases with mutations in the transcriptional regulator MECP2. At present, there are no effective treatments for the disorder. Despite recent advances in RTT genetics and neurobiology, most drug development programs have focused on compounds targeting the IGF-1 pathway and no pivotal trial has been completed as yet. Thus, testing novel drugs that can ameliorate RTT's clinical manifestations is a high priority. ANAVEX2-73 (blarcamesine) is a Sigma-1 receptor agonist and muscarinic receptor modulator with a strong safety record and preliminary evidence of efficacy in patients with Alzheimer's disease. Its role in calcium homeostasis and mitochondrial function, cellular functions that underlie pathological processes and compensatory mechanisms in RTT, makes blarcamesine an intriguing drug candidate for this disorder. Mice deficient in MeCP2 have a range of physiological and neurological abnormalities that mimic the human syndrome. We tested blarcamesine in female heterozygous mice carrying one null allele of Mecp2 (HET) using a two-tier approach, with age-appropriate tests. Administration of the drug to younger and older adult mice resulted in improvement in multiple motor, sensory, and autonomic phenotypes of relevance to RTT. The latter included motor coordination and balance, acoustic and visual responses, hindlimb clasping, and apnea in expiration. In line with previous animal and human studies, blarcamesine also showed a good safety profile in this mouse model of RTT. Clinical studies in RTT with blarcamesine are ongoing.
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Affiliation(s)
- Walter E Kaufmann
- Anavex Life Sciences Corp., 51 West 52nd Street, 7th floor, New York, NY 10019, USA; Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322.
| | - Jeffrey Sprouse
- Anavex Life Sciences Corp., 51 West 52nd Street, 7th floor, New York, NY 10019, USA
| | - Nell Rebowe
- Anavex Life Sciences Corp., 51 West 52nd Street, 7th floor, New York, NY 10019, USA
| | - Taleen Hanania
- PsychoGenics Inc., 215 College Road, Paramus, NJ 07652, USA
| | - Daniel Klamer
- Anavex Life Sciences Corp., 51 West 52nd Street, 7th floor, New York, NY 10019, USA
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