TABLE 1.
Summary of monogenic variants for a series of 17 cases of DEE/EE with ESES.
| ID | Epilepsy gene | Method(s)of identification | Suspected or known pathogenic mutation | Zygosity | Inheritance pattern | Phenotype | In silico predictions | ExAC database | Pathogenicity |
| 1 | KCNQ2 | Clinical gene panel | c.736G>C (p.Ala246Pro) | Heterozygous | De novo | IS → ESES without syndrome | PP-2: 0.919 SIFT: 0 | Not found | Likely pathogenic |
| 2 | KCNQ2 | Clinical gene panel | c.998G>A (p.Arg333Gln) | Heterozygous | paternal | DEE without syndrome → ABPE | PP-2: 0.999 SIFT: 0.003 | Not found | Likely pathogenic |
| 3 | KCNQ2 | Clinical gene panel | c.920T>C (p.Leu307Pro) | Heterozygous | De novo | OS → ESES without syndrome | PP-2: 1.000 SIFT: 0 | Not found | Likely pathogenic |
| 4 | KCNQ2 | Clinical gene panel | c.832A>T (p.Ile278Phe) | Heterozygous | De novo | OS → ESES without syndrome | PP-2: 0.959 SIFT: 0 | Not found | Likely pathogenic |
| 5 | KCNQ2 | Clinical gene panel | c.740C>T (p.Ser247Leu) | Heterozygous | De novo | DEE without syndrome → ESES without epilepsy | PP-2: 0.678 SIFT: 0 | Not found | Likely pathogenic |
| 6 | KCNQ2 | Clinical gene panel | c.952C>G (p.Leu318Val) | Heterozygous | De novo | IS → ESES without epilepsy | PP-2: 0.998 SIFT: 0.001 | Not found | Likely pathogenic |
| 7 | KCNA2 | Clinical WES | c.1214C>T (p.Pro405Leu) | Heterozygous | paternal | EE without syndrome → ABPE | PP-2: 1.000 SIFT: 0 | Not found | Pathogenic |
| 8 | KCNA2 | Clinical WES | c.1214C>T (p.Pro405Leu) | Heterozygous | De novo | EE without syndrome → ABPE | PP-2: 1.000 SIFT: 0 | Not found | Pathogenic |
| 9 | KCNA2 | Clinical gene panel | c.1214C>T (p.Pro405Leu) | Heterozygous | De novo | EE without syndrome → ABPE | PP-2: 1.000 SIFT: 0 | Not found | Pathogenic |
| 10 | KCNA2 | Research exome | c.1214C>T (p.Pro405Leu) | Heterozygous | De novo | EE without syndrome → ABPE | PP-2: 1.000 SIFT: 0 | Not found | Pathogenic |
| 11 | KCNA2 | Clinical gene panel | c.1214C>T (p.Pro405Leu) | Heterozygous | De novo | EE without syndrome → ABPE | PP-2: 1.000 SIFT: 0 | Not found | Pathogenic |
| 12 | GRIN2A | Clinical gene panel | c.1034delG (p.Gly345Alafs*19) | Heterozygous | De novo | ABPE | N/A | Not found | Pathogenic |
| 13 | GRIN2A | Clinical WES | c.2107C>T (p.Gln703*) | Heterozygous | De novo | ABPE | N/A | Not found | Pathogenic |
| 14 | GRIN2A | Clinical WES | c.1592C>T (p.Thr531Met) | Heterozygous | De novo | ABPE | PP-2: 1.000 SIFT: 0 | Not found | Likely pathogenic |
| 15 | SLC9A6 | Clinical gene panel | c.1178_1180del (p.394del) | Hemizygous | X-linked | CSWS | N/A | Not found | Pathogenic |
| 16 | HIVEP2 | Clinical WES | c.5935C>T (p.Arg1979*) | Heterozygous | De novo | ABPE | N/A | Not found | Pathogenic |
| 17 | RARS2 | Clinical WES | c.[991A>G; 1718C>T] p.[Ile331Val; Thr573Ile] | Compound heterozygous | AR | DEE without syndrome → ABPE | PP-2: 0.670 SIFT: 0.013 | Not found | Likely pathogenic |
DEE, development and epileptic encephalopathy; EE, epileptic encephalopathy; ESES, epileptic encephalopathy with electrical status epilepticus during sleep; IS, infantile spasms; PP-2, PolyPhen2; ABPE, epileptic encephalopathy of atypical benign partial epilepsy; OS, Ohtahara syndrome; WES, whole exome sequencing; CSWS, epileptic encephalopathy with continuous spike-and-wave during sleep; AR, autosomal recessive. The symbol * is used to indicate a translation termination (stop) codon.