BACKGROUND A family with a complicated constellation of neurologic findings, including neuropathy, myotonia, and periodic paralysis, has been described in 4 studies in the medical literature since 1934. The underlying cause of their disease has been the subject of considerable speculation and has never been identified until now. OBJECTIVE To identify the molecular basis of this family's neuro...

Generalized epilepsy with febrile seizures-plus (GEFS) is a benign Mendelian syndrome characterized by childhood-onset febrile and afebrile seizures. Three point mutations within two voltage-gated sodium channel genes have been identi®ed so far: in GEFS type 1 a mutation in the b1-subunit gene SCN1B, and in GEFS type 2 two mutations within the neuronal a-subunit gene SCN1A. Functional expressio...

Generalized epilepsy with febrile seizures plus (GEFS+) is a benign epileptic syndrome of humans. It is characterized by febrile and afebrile generalized seizures that occur predominantly in childhood and respond well to standard antiepileptic therapy. A mutation in the b1-subunit of the voltage-gated sodium channel, linked to chromosome 19q13 (GEFS+ type 1) has been found in one family. For fo...

Hypokalemic periodic paralysis (HypoPP) is an autosomal dominant disorder characterized by episodic attacks of muscle weakness associated with a decrease in blood potassium levels. Recently, mutations in the gene coding for the skeletal muscle voltage-gated sodium channel alpha subunit (SCN4A) have been reported. We detected the R672H mutation in one HypoPP Turkish family.

Generalized epilepsy with febrile seizures-plus (GEFS+) is a benign Mendelian syndrome characterized by childhood-onset febrile and afebrile seizures. Three point mutations within two voltage-gated sodium channel genes have been identified so far: in GEFS+ type 1 a mutation in the beta1-subunit gene SCN1B, and in GEFS+ type 2 two mutations within the neuronal alpha-subunit gene SCN1A. Functiona...

In a myasthenic syndrome associated with fatigable generalized weakness and recurrent attacks of respiratory and bulbar paralysis since birth, nerve stimulation at physiologic rates rapidly decremented the compound muscle action potential. Intercostal muscle studies revealed no abnormality of the resting membrane potential, evoked quantal release, synaptic potentials, acetylcholine receptor cha...