Table 2. [Selected Genes To Consider in the Differential Diagnosis of KCNQ2-Related Epilepsy]. - GeneReviews®

Gene(s)	Epilepsy Phenotype	MOI	Clinical Features of DiffDx Disorder
KCNQ3	Self-limited familial neonatal epilepsy (SLFNE)	AD	KCNQ2-SLFNE & KCNQ3-SLFNE are clinically indistinguishable; thus, molecular genetic testing of both genes is commonly performed when SLFNE is suspected.
PRRT2 SCN2A SCN8A	Self-limited familial infantile epilepsy (SLFIE) & self-limited familial neonatal-infantile epilepsy (SLFNIE) (OMIM PS601764)	AD	SLFIE & SLFNIE can closely resemble SLFNE in rare instances. In SLFIE, seizure onset is nearly always by age ~6 mos. In SLFNIE, age of seizure onset can vary w/in a family & incl both neonatal & infantile onset. ¹
>100 genes; more commonly involved genes: ARX SCN2A SCN8A STXBP1	Neonatal-onset developmental & epileptic encephalopathy (NEO-DEE) (OMIM PS308350)	XL AD ²	When seizure onset is w/in the 1st few days of term birth, KCNQ2 is the most commonly involved gene; when seizures begin later in the neonatal period, the chance that another gene is involved ↑. ³ No other clinical features or EEG findings discriminating among these candidates are known.

Gene(s)

Epilepsy Phenotype

MOI

Clinical Features of DiffDx Disorder

Self-limited familial neonatal epilepsy (SLFNE)

KCNQ2-SLFNE & KCNQ3-SLFNE are clinically indistinguishable; thus, molecular genetic testing of both genes is commonly performed when SLFNE is suspected.

PRRT2
SCN2A
SCN8A

Self-limited familial infantile epilepsy (SLFIE) & self-limited familial neonatal-infantile epilepsy (SLFNIE) (OMIM PS601764)

SLFIE & SLFNIE can closely resemble SLFNE in rare instances. In SLFIE, seizure onset is nearly always by age ~6 mos. In SLFNIE, age of seizure onset can vary w/in a family & incl both neonatal & infantile onset. ¹

>100 genes; more commonly involved genes:
ARX
SCN2A
SCN8A
STXBP1

Neonatal-onset developmental & epileptic encephalopathy (NEO-DEE) (OMIM PS308350)

XL
AD ²

When seizure onset is w/in the 1st few days of term birth, KCNQ2 is the most commonly involved gene; when seizures begin later in the neonatal period, the chance that another gene is involved ↑. ³ No other clinical features or EEG findings discriminating among these candidates are known.

From: KCNQ2-Related Disorders

GeneReviews^® [Internet].

Adam MP, Feldman J, Mirzaa GM, et al., editors.

Seattle (WA): University of Washington, Seattle; 1993-2024.

GeneReviews® chapters are owned by the University of Washington. Permission is hereby granted to reproduce, distribute, and translate copies of content materials for noncommercial research purposes only, provided that (i) credit for source (http://www.genereviews.org/) and copyright (© 1993-2024 University of Washington) are included with each copy; (ii) a link to the original material is provided whenever the material is published elsewhere on the Web; and (iii) reproducers, distributors, and/or translators comply with the GeneReviews® Copyright Notice and Usage Disclaimer. No further modifications are allowed. For clarity, excerpts of GeneReviews chapters for use in lab reports and clinic notes are a permitted use.

For more information, see the GeneReviews® Copyright Notice and Usage Disclaimer.

For questions regarding permissions or whether a specified use is allowed, contact: ude.wu@tssamda.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.