Letter to the Editor Regarding the Article “Whole-Exome Sequencing in NF1-Related West's Syndrome Leads to the Identification of KCNC2 as a Novel Candidate Gene for Epilepsy”

We read with interest the short communication by Rademache et al,[1] particularly addressing the whole-exome sequencing (WES) reevaluation of patients with neurofibromatosis type 1 (NF1).

This article provides an interesting suggestion about how a systematic genetic analysis could find potentially secondary genetic etiologies in patients with NF1, and we believe that this approach could be extended to other diseases.

The authors identified a de novo variant in KCNC2 gene (c.G499T and p.D167Y) coding for Kv3.2 potassium channel in a patient with NF1 and suggested that this mutation could play a role in the pathogenesis of drug-resistant epilepsy of this subject. The authors also assume that Kv3.2 was previously undescribed in literature as correlated to epilepsy.

However, at Oasi Research Institute-IRCCS (Troina, Italy), we had previously identified a heterozygous de novo variant c.1411G > C (p.Val471Leu) in the KCNC2 gene in a patient with early severe developmental and epileptic encephalopathy.[2] The first online version of our article was published on January 20, 2020 but Rademache et al and reviewers must have missed it before the publication of their work.

The research of Rademache et al confirmed the likely dominant inheritance of KCNC2 gene and suggested a broad phenotype related to KCNC2 variants. We hope that a larger genotype–phenotype correlation study, taking into account the existing literature data, will be able to shed light on the implications of KCNC2 mutations.

Publication History

Received: 10 June 2020

Accepted: 23 July 2020

Article published online:
27 October 2020

• References

• 1 Rademacher A, Schwarz N, Seiffert S. et al. Whole-exome sequencing in nf1-related West syndrome leads to the identification of KCNC2 as a novel candidate gene for epilepsy. Neuropediatrics 2020; (e-pub ahead of print). DOI: 10.1055/s-0040-1710524.
• 2 Vetri L, Calì F, Vinci M. et al. A de novo heterozygous mutation in KCNC2 gene implicated in severe developmental and epileptic encephalopathy. Eur J Med Genet 2020; 63 (04) 103848