1
|
Dhar D, Holla VV, Kumari R, Sriram N, Saini J, Yadav R, Pandey A, Kamble N, Muthusamy B, Pal PK. KMT2B-Related Dystonia in Indian Patients With Literature Review and Emphasis on Asian Cohort. J Mov Disord 2023; 16:285-294. [PMID: 37309110 PMCID: PMC10548078 DOI: 10.14802/jmd.23035] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 05/12/2023] [Accepted: 05/29/2023] [Indexed: 06/14/2023] Open
Abstract
OBJECTIVE aaMutations in the KMT2B gene have been identified in patients previously diagnosed with idiopathic dystonia. Literature on KMT2B-related dystonia is sparse in the Indian and Asian populations. METHODS aaWe report seven patients with KMT2B-related dystonia studied prospectively from May 2021 to September 2022. Patients underwent deep clinical phenotyping and genetic testing by whole-exome sequencing (WES). A systematic literature search was performed to identify the spectrum of previously published KMT2B-related disorders in the Asian subcontinent. RESULTS aaThe seven identified patients with KMT2B-related dystonia had a median age at onset of four years. The majority experienced onset in the lower limbs (n = 5, 71.4%), with generalization at a median duration of 2 years. All patients except one had complex phenotypes manifesting as facial dysmorphism (n = 4), microcephaly (n = 3), developmental delay (n = 3), and short stature (n = 1). Magnetic resonance imaging (MRI) abnormalities were present in four cases. WES revealed novel mutations in the KMT2B gene in all patients except one. Compared to the largest cohort of patients with KMT2B-related disorders, the Asian cohort, comprising 42 patients, had a lower prevalence of female patients, facial dysmorphism, microcephaly, intellectual disability, and MRI abnormalities. Protein-truncating variants were more prevalent than missense variants. While microcephaly and short stature were more common in patients with missense mutations, facial dysmorphism was more common in patients with truncating variants. Deep brain stimulation, performed in 17 patients, had satisfactory outcomes. CONCLUSION aaThis is the largest series of patients with KMT2B-related disorders from India, further expanding the clinico-genotypic spectrum. The extended Asian cohort emphasizes the unique attributes of this part of the world.
Collapse
Affiliation(s)
- Debjyoti Dhar
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Vikram V Holla
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Riyanka Kumari
- Institute of Bioinformatics, International Technology Park, Bengaluru, Karnataka, India
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Neeharika Sriram
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Jitender Saini
- Department of Neuroimaging and Intervention Radiology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Ravi Yadav
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Akhilesh Pandey
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | - Nitish Kamble
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Babylakshmi Muthusamy
- Institute of Bioinformatics, International Technology Park, Bengaluru, Karnataka, India
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| |
Collapse
|
2
|
Monfrini E, Ciolfi A, Cavallieri F, Ferilli M, Soliveri P, Pedace L, Erro R, Del Sorbo F, Valzania F, Fioravanti V, Cossu G, Pellegrini M, Salviati L, Invernizzi F, Oppo V, Murgia D, Giometto B, Picillo M, Garavaglia B, Morgante F, Tartaglia M, Carecchio M, Di Fonzo A. Adult-onset KMT2B-related dystonia. Brain Commun 2022; 4:fcac276. [PMID: 36483457 PMCID: PMC9724767 DOI: 10.1093/braincomms/fcac276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 08/30/2022] [Accepted: 10/24/2022] [Indexed: 07/25/2023] Open
Abstract
KMT2B-related dystonia (DYT-KMT2B, also known as DYT28) is an autosomal dominant neurological disorder characterized by varying combinations of generalized dystonia, psychomotor developmental delay, mild-to-moderate intellectual disability and short stature. Disease onset occurs typically before 10 years of age. We report the clinical and genetic findings of a series of subjects affected by adult-onset dystonia, hearing loss or intellectual disability carrying rare heterozygous KMT2B variants. Twelve cases from five unrelated families carrying four rare KMT2B missense variants predicted to impact protein function are described. Seven affected subjects presented with adult-onset focal or segmental dystonia, three developed isolated progressive hearing loss, and one displayed intellectual disability and short stature. Genome-wide DNA methylation profiling allowed to discriminate these adult-onset dystonia cases from controls and early-onset DYT-KMT2B patients. These findings document the relevance of KMT2B variants as a potential genetic determinant of adult-onset dystonia and prompt to further characterize KMT2B carriers investigating non-dystonic features.
Collapse
Affiliation(s)
- Edoardo Monfrini
- Dino Ferrari Center, Neuroscience Section, Department of Pathophysiology and Transplantation, University of Milan, Milan 20122, Italy
- Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan 20122, Italy
| | - Andrea Ciolfi
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Francesco Cavallieri
- Neurology Unit, Neuromotor & Rehabilitation Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia 42124, Italy
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, Reggio Emilia 42124, Italy
| | - Marco Ferilli
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Paola Soliveri
- Parkinson Institute, ASST G. Pini-CTO, Milan 20126, Italy
- Fondazione Grigioni per il Morbo di Parkinson, Milan 20125, Italy
| | - Lucia Pedace
- Department of Onco-Hematology, Cell Therapy, Gene Therapy and Hemopoietic Transplant, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00165, Italy
| | - Roberto Erro
- Department of Medicine, Surgery and Dentistry ‘Scuola Medica Salernitana’, Neuroscience Section, University of Salerno, Baronissi, SA 84081, Italy
| | - Francesca Del Sorbo
- Parkinson Institute, ASST G. Pini-CTO, Milan 20126, Italy
- Fondazione Grigioni per il Morbo di Parkinson, Milan 20125, Italy
| | - Franco Valzania
- Neurology Unit, Neuromotor & Rehabilitation Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia 42124, Italy
| | - Valentina Fioravanti
- Neurology Unit, Neuromotor & Rehabilitation Department, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia 42124, Italy
| | - Giovanni Cossu
- Department of Neuroscience, Brotzu Hospital, Cagliari 09047, Italy
| | - Maria Pellegrini
- Neurology Unit, Trento Hospital, Azienda Provinciale per i Servizi Sanitari (APSS) di Trento, Trento 38122, Italy
| | - Leonardo Salviati
- Clinical Genetics Unit, Department of Woman and Child Health, University of Padova, Padova 35131, Italy
| | - Federica Invernizzi
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico C. Besta, Milano 20126, Italy
| | - Valentina Oppo
- Department of Neuroscience, Brotzu Hospital, Cagliari 09047, Italy
| | - Daniela Murgia
- Department of Neuroscience, Brotzu Hospital, Cagliari 09047, Italy
| | - Bruno Giometto
- Neurology Unit, Trento Hospital, Azienda Provinciale per i Servizi Sanitari (APSS) di Trento, Trento 38122, Italy
| | - Marina Picillo
- Department of Medicine, Surgery and Dentistry ‘Scuola Medica Salernitana’, Neuroscience Section, University of Salerno, Baronissi, SA 84081, Italy
| | - Barbara Garavaglia
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico C. Besta, Milano 20126, Italy
| | - Francesca Morgante
- Neurosciences Research Centre, Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW170RE, United Kingdom
- Department of Experimental and Clinical Medicine, University of Messina, Messina 98122, Italy
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | | | - Alessio Di Fonzo
- Correspondence to: Alessio Di Fonzo, MD PhD Via Francesco Sforza 35, 20122, Milan, Italy E-mail:
| |
Collapse
|
3
|
Rangel YA, Espinosa E. Early-onset generalized dystonia caused by a new mutation in the KMT2B gene: Case report. BIOMEDICA : REVISTA DEL INSTITUTO NACIONAL DE SALUD 2022; 42:429-434. [PMID: 36122281 PMCID: PMC9528928 DOI: 10.7705/biomedica.6296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
Introduction: KMT2B-related dystonia is a recently described subtype of focal-onset dystonia in the lower limbs, evolving into a generalized form with cervical, oropharyngeal involvement, dysarthria, swallowing disorder and intellectual disability. Clinical case: We describe the case of a 10-year-old female patient, without a history of consanguinity or neurological disease. She manifested abnormal gait and dystonia with focal onset and progressive course with evolution into generalized dystonia, affecting orofacial and bulbar muscles, significant alteration of language and swallowing. Metabolic and systemic studies, including neuroimaging, were found to be normal. A complete genomic sequencing study was performed identifying a new, probably pathogenic, heterozygous variant in the KMT2B gene, c.1205delC, p. (Pro402Hisfs*5), causing displacement in the reading frame, a finding that explains the patient’s phenotype and it is associated to autosomal dominant childhood-onset dystonia-28. Conclusion: We report a new heterozygous mutation in the KMT2B gene as a cause of generalized early-onset dystonia not reported in the literature until the date. The diagnosis of this pathology has implications for the treatment and prognosis of patients, given that therapeutic strategies implemented early can prevent the fast deterioration and severe course of this disease.
Collapse
Affiliation(s)
- Yully Andrea Rangel
- Servicio de Neurología Pediátrica, Hospital Militar Central, Universidad Militar Nueva Granada, Bogotá, D.C., Colombia.
| | - Eugenia Espinosa
- Servicio de Neurología Pediátrica, Hospital Militar Central, Universidad Militar Nueva Granada, Bogotá, D.C., Colombia.
| |
Collapse
|