Mutation information:
NumberExon/IntronNucleotide change Protein changeLocation Mutation typeConsequencesPhenotype InheritanceReference
146926c.4968C>Gp.Ile1656MetDIVS4MissenseN→N (10); DEGEFS+Familial(Maternal,FS+),P=4/4Wallace RH.2001

Functional information:
NumberNucleotide changeProtein changeLocationPhenotypeFunctional defect type Details of the major biophysical abnormalities.Reference
40c.4968C>Gp.Ile1656Met(I1656M)DIVS4GEFS+ fDE Hypoexcitable (positive) shift of activation and negative shift of inactivation.Lossin C. 2003

Inheritance information:
NumberNucleotide changeProtein changeMutation type Proband's phenotype1st transmitter's phenotype Mosaic Affected generationsPenetranceReference
141c.4968C>Gp.Ile1656Met(DIVS4)MissenseGEFS+FS+(Maternal) 24/4Wallace RH.2001

[c.4968C>G] Clinical description

The Israeli family was of Druze origin; the parents were from different but proximate villages and were not known to be related. This family spans two generations, and four family members had seizures. The proband, I-2, age 41 years, had had hundreds of tonic-clonic seizures, sometimes with fever. These began at age four years and continued, at a rate of approximately one per month, until the time of the study. The proband was mildly intellectually impaired. EEG showed generalized irregular spike-wave and polyspike-wave discharges, and FS+ was diagnosed. Of her four children, the oldest, II-1, was unaffected, two, II-2 and II-4, had FS, and one, II-3, had FS+(Wallace RH, et al. Am J Hum Genet. 2001 Apr;68(4):859-65.[11254444]).