Table 1.
Group | Patient | Current age | Mutation/sequence variant | Presumed effect | Age of seizure onset | References |
---|---|---|---|---|---|---|
(i) | 1 | 4 y | c.[284G>A] (M) + c.[148G> A];c.[364-1G>A]a (P) | p.R95H (M) + p.E50K;Splice errors a (P) | 30 min | Mills et al., 2005; Khayat et al., 2008 |
2 | 5 y 2 m | c.[98A>T] + c.[98A>T] | p.D33V + p.D33V | 6 h | Hoffmann et al., 2007 | |
3 | 2 y 7 m | c.[637C>T] + c.[637C>T] | p.P213S + p.P213S | 90 min | Novel | |
4* | 4 m | c.[637C>T] + c.[637C>T] | p.P213S + p.P213S | None* | Novel | |
5 | 1 y | c.[283C>T] (M) + c.[283C>T] (P) | p.R95C (M) + p.R95C (P) | 2 h | Khayat et al., 2008 | |
6 | 4 y | c.[641dupA] +?** | p.Q214fs +? ** | 5 h | Novel | |
(ii) | 7 | 6 y 5 m | c.[347G>A] (M) + c.[347G>A] (P) | p.R116Q (M) + p.R116Q (P) | 5 m | Novel |
(iii) | 8 | 9 y | c.[347G>A] + c.[347G>A] | p.R116Q + p.R116Q | 3 h | Novel |
9 | 2 y | c.[98A>T] + c.[998A>T] | p.D33V + p.D33V | 3 w | Hoffmann et al., 2007 | |
10 | 23 y | c.[98A>T] + c.[358G>A] | p.D33V + p.E120K | 2 m | Hoffmann et al., 2007 + novel | |
11 | 21 y | c.[98A>T] (P) + c.264-21_ 264-1delinsC (M) | p.D33V (P) + Splice errors (M) | 3 h | Hoffmann et al., 2007 + novel | |
12 | 41 y | c.[98A>T] + c.[347G>A] + c. [673C>T] | p.D33V + p.R116Q + p.R225Cb | 14 d | Hoffmann et al., 2007 + novel + Veerapandiyan et al., 2011 | |
13 | 9 y | c.[674G>A] + c.[674G>A] | p.R225H + p.R225H | 24 h | Novel | |
14 | 3 y | c.[347G>A];c.[674G>A] + c.[347G >A];c.[674G>A] | p.R116Q;p.R225H + p.R116Q;p.R225H c | 30 min | Novel | |
15 | 9 y | c.[347G>A];c.[674G>A] + c.[347G >A];c.[674G>A] | p.R116Q;p.R225H + p.R116Q;p.R225H c | 10 h | Novel |
(i) Neonatal onset seizures responding to pyridoxal 5’-phosphate;
(ii) Infantile spasms (onset 5 months) responsive to pyridoxal 5’-phosphate;
(iii) Seizures starting under 3 months of age responding to pyridoxine.
Where parent DNA available inheritance was investigated and the allele carrying the mutation is indicated as P (paternal) or M (maternal).
*Sibling of Patient 3, no seizures as treated prophylactically;
**Second mutation not found, complementary DNA and genomic DNA sequenced;
ac.[148G>A] and c.[364-1G>A] were inherited in cis, this was confirmed by analysing parental DNA;
b No parental DNA was available to ascertain which muation R116Q was in cis with;
cAssume that R116Q has been inherited in cis with R225H, no parental DNA was available to confirm this.