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Journal of Pediatric Neurology 2023; 21(06): 467-471
DOI: 10.1055/s-0043-1769476
Case Report

A Child with KMT2B-Related Acute-Onset Dystonia: Clinical Pointers to Molecular Diagnosis

Ankur Singh 
1   Division of Genetics and Metabolic Disorder, Department of Paediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
,
Sucheta Sucheta
2   Department of Paediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
,
Abhishek Abhinay
2   Department of Paediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
,
Rajniti Prasad
2   Department of Paediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
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Abstract

Dystonia is common extrapyramidal presentation of neurological problems in childhood. The causes could range from infectious, autoimmune, drug-induced, or genetic in origin. Genetic causes are rare in origin but could masquerade the common causes. Recently, KMT2B-related dystonia has been identified as a common genetic cause of dystonia in childhood. We present a case of a 3.5-year-old with 18 months of follow-up, who was diagnosed with KMT2B-related dystonia and managed with antidystonia drugs to an acceptable level where she could perform her day-to-day work with ease. Here, we highlight certain clinical pointers of the disease and the need of special genetic test in diagnosing such cases. We also tabulated the three previously reported Indian cases and compared their parameter with ours.

Keywords

dystonia - KMT2B - childhood

Authors' Contributions

A.S. and Sucheta collected the data and A.S. conceptualized the idea, wrote the manuscript, and is the first author. A.A. helped in case management and literature search. R.P. critically analyzed the manuscript.




Publication History

Received: 11 March 2023

Accepted: 24 April 2023

Article published online:
29 May 2023

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  • References

  • 1 Zech M, Boesch S, Maier EM. et al. Haploinsufficiency of KMT2B, encoding the lysine-specific histone methyltransferase 2B, results in early-onset generalized dystonia. Am J Hum Genet 2016; 99 (06) 1377-1387
    CrossrefPubMedGoogle Scholar
  • 2 Sanger TD, Chen D, Fehlings DL. et al. Definition and classification of hyperkinetic movements in childhood. Mov Disord 2010; 25 (11) 1538-1549
    CrossrefPubMedGoogle Scholar
  • 3 Meyer E, Carss KJ, Rankin J. et al; UK10K Consortium; Deciphering Developmental Disorders Study; NIHR BioResource Rare Diseases Consortium. Mutations in the histone methyltransferase gene KMT2B cause complex early-onset dystonia. Nat Genet 2017; 49 (02) 223-237
    CrossrefPubMedGoogle Scholar
  • 4 Carecchio M, Invernizzi F, Gonzàlez-Latapi P. et al. Frequency and phenotypic spectrum of KMT2B dystonia in childhood: a single-center cohort study. Mov Disord 2019; 34 (10) 1516-1527
    CrossrefPubMedGoogle Scholar
  • 5 Pandey S, Bhattad S, Panda AK, Mahadevan L. Late-onset KMT2B-related dystonia in an Indian patient with normal cognition, dystonic opisthotonus and lack of oromandibular and laryngeal involvement. Parkinsonism Relat Disord 2020; 74: 33-35
    CrossrefPubMedGoogle Scholar
  • 6 Padmanabha H, Awati AM, Thomas K, Sarma GK R. A novel mutation in KMT2B gene causing childhood-onset generalized dystonia with expanded phenotype from India. Neurol India 2021; 69 (05) 1400-1401
    PubMedGoogle Scholar
  • 7 Rajan R, Garg K, Saini A. et al. Pallidal deep brain stimulation for KMT2B related dystonia in an Indian patient. Ann Indian Acad Neurol 2021; 24 (04) 586-588
    CrossrefPubMedGoogle Scholar
  • 8 Cif L, Demailly D, Lin JP. et al; Deciphering Developmental Disorders Study; Genomics England Research Consortium; NIHR BioResource; Undiagnosed Diseases Network. KMT2B-related disorders: expansion of the phenotypic spectrum and long-term efficacy of deep brain stimulation. Brain 2020; 143 (11) 3242-3261
    CrossrefPubMedGoogle Scholar