Abstract
Background
Heterozygous KCNQ2 variants cause benign familial neonatal seizures and early-onset epileptic encephalopathy
in an autosomal dominant manner; the latter is called KCNQ2 encephalopathy. No case of KCNQ2 encephalopathy with arthrogryposis multiplex congenita has been reported. Furthermore,
early-onset scoliosis and opisthotonus have not been documented as characteristics
of KCNQ2 encephalopathy.
Case report
A male infant born with scoliosis and arthrogryposis multiplex congenita developed
intractable epilepsy on the second day of life. At 4 months of age, he developed opisthotonus.
The opisthotonus was refractory to medication in the beginning, and it spontaneously
disappeared at 8 months of age. Whole-exome sequencing revealed a novel de novo heterozygous variant in KCNQ2, NM_172107.4:c.839A > C, p.(Tyr280Ser).
Conclusions
Early-onset scoliosis, arthrogryposis multiplex congenita, and opisthotonus may be
related to KCNQ2 encephalopathy.
Keywords
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References
- Unexplained early onset epileptic encephalopathy: exome screening and phenotype expansion.Epilepsia. 2016; 57: e12-e17
- KCNQ2 encephalopathy: emerging phenotype of a neonatal epileptic encephalopathy.Ann Neurol. 2012; 71: 15-25
- Arthrogryposis multiplex congenita.Brain Dev. 1998; 20: 507-511
- Early-onset scoliosis: current treatment.Orthop Traumatol Surg Res. 2015; 101: S109-S118
- Treatment of scoliosis associated with arthrogryposis multiplex congenita.J Pediatr Orthop. 2017; 37: S24-S26
- The genetic landscape of epilepsy of infancy with migrating focal seizures.Ann Neurol. 2019; 86: 821-831
- Botulinum neurotoxin injections in childhood opisthotonus.Toxins (Basel). 2021; 13: 137
- Clinical spectrum of early onset epileptic encephalopathies caused by KCNQ2 mutation.Epilepsia. 2013; 54: 1282-1287
- Six years' accomplishment of the Initiative on Rare and Undiagnosed Diseases: nationwide project in Japan to discover causes, mechanisms, and cures.J Hum Genet. 2022; 67: 505-513
- Human genetic variation database, a reference database of genetic variations in the Japanese population.J Hum Genet. 2016; 61: 547-553
- The mutational constraint spectrum quantified from variation in 141,456 humans.Nature. 2020; 581: 434-443
- Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology.Genet Med. 2015; 17: 405-424
- Gene mutation analysis of 175 Chinese patients with early-onset epileptic encephalopathy.Clin Genet. 2017; 91: 717-724
- KCNQ2 encephalopathy: delineation of the electroclinical phenotype and treatment response.Neurology. 2014; 82: 368-370
- Early-onset scoliosis: a review of history, current treatment, and future directions.Pediatrics. 2016; 137: e20150709
- Recessive mutations in SLC35A3 cause early onset epileptic encephalopathy with skeletal defects.Am J Med Genet A. 2017; 173: 1119-1123
- De novo pathogenic variants in CACNA1E cause developmental and epileptic encephalopathy with contractures, macrocephaly, and dyskinesias.Am J Hum Genet. 2018; 103: 666-678
- De Novo mutations of SCN1A are responsible for arthrogryposis broadening the SNC1A-related phenotypes.J Med Genet. 2021; 58: 737-742
- Epileptic and nonepileptic features in patients with early onset epileptic encephalopathy and STXBP1 mutations.Epilepsia. 2011; 52: 1828-1834
- Time-limited alterations in cortical activity of a knock-in mouse model of KCNQ2-related developmental and epileptic encephalopathy.J Physiol. 2022; 600: 2429-2460
- Clinical and genetic overview of paroxysmal movement disorders and pisodic ataxias.Int J Mol Sci. 2020; 21: 3603
Article info
Publication history
Published online: January 09, 2023
Accepted:
December 27,
2022
Received in revised form:
December 26,
2022
Received:
August 11,
2022
Publication stage
In Press Corrected ProofIdentification
Copyright
© 2022 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
