Juvenile myoclonic epilepsy (JME) is the most frequent cause of hereditary grand mal seizures. We previously mapped and narrowed a region associated with JME on chromosome 6p12-p11 (EJM1). Here, we describe a new gene in this region, EFHC1, which encodes a protein with an EF-hand motif. Mutation analyses identified five missense mutations in EFHC1 that cosegregated with epilepsy or EEG polyspike wave in affected members of six unrelated families with JME and did not occur in 382 control individuals. Overexpression of EFHC1 in mouse hippocampal primary culture neurons induced apoptosis that was significantly lowered by the mutations. Apoptosis was specifically suppressed by SNX-482, an antagonist of R-type voltage-dependent Ca(2+) channel (Ca(v)2.3). EFHC1 and Ca(v)2.3 immunomaterials overlapped in mouse brain, and EFHC1 coimmunoprecipitated with the Ca(v)2.3 C terminus. In patch-clamp analysis, EFHC1 specifically increased R-type Ca(2+) currents that were reversed by the mutations associated with JME.

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Chorea-acanthocytosis is a neurodegenerative disorder with peripheral red cell acanthocytosis. Linkage of chorea-acanthocytosis to chromosome 9q21 has been found. We refined the locus region and identified a previously unknown, full-length cDNA encoding a presumably structural protein, which we called chorein. We found a deletion in the coding region of the cDNA leading to a frame shift resulting in the production of a truncated protein in both alleles of patients and in single alleles of obligate carriers.

Acad. Sci. USA (97, 13913-13918; First Published November 28, 2000; 10.1073͞pnas.250478897), the authors note that the exponents of some entries in Table 1 were misprinted. The correct values appear below. www.pnas.org͞cgi͞doi͞10.1073͞pnas.191384698 STATISTICS, GENETICS. For the article ''Significance analysis of microarrays applied to the ionizing radiation response'' by Virginia Goss Tusher, Robert Tibshirani, and Gilbert Chu, which appeared in number 9, April 24, 2001, of Proc. Natl. Acad. Sci. USA (98, 5116-5121; First Published April 17, 2001; 10.1073͞pnas.091062498), the authors note the following: ''In our discussion of the pairwise fold change method on page 5118, we cited a paper by Ly et al., crediting them for the method. We did not mean to imply that it was deficient for the analysis of their experiments. In fact, Ly et al. incorporate (98,(6384)(6385)(6386)(6387)(6388)(6389), the authors wish to correct the position given for the amino acid that was mutated in the patient. The mutation ''R187W'' should be ''R188W. '' www.pnas.org͞cgi͞doi͞10.1073͞pnas.191390798 FEB2, 19p; FEB3, and FEB4,. A small population of individuals with FS has additional generalized epilepsy (1) or afebrile seizures. Genes for a ␤-subunit (␤1) and an ␣ I -subunit (Na v 1.1: SCN1A) (10) of the neuronal voltage-gated Na ϩ channel have been identified to be responsible for generalized epilepsy with febrile seizures plus (GEFSϩ) type 1 and 2, respectively (11, 12). However, a large number of patients with GEFSϩ still show no mutation for those genes. These, therefore, suggest that other genes might also be involved in GEFSϩ and FS associated with afebrile seizures. The chromosomal locus 2q24, in which GEFSϩ has been mapped, harbors not only Na v 1.1 but also other ␣-subunits including Na v 1.2 (SCN2A) (10,(13)(14)(15). Given that Na v 1.2 is also expressed in high levels in the central nervous system with a tissue-specific profile (16), Na v 1.2 is an intriguing candidate. In the present study, we report a mutation of Na v 1.2 found in a patient with FS and afebrile seizures. A channel harboring the mutation shows abnormal electrophysiological properties that may underlie the neuronal hyperexcitability that triggers seizure activity. Materials and MethodsPatients and Pedigrees. This study recruited nineteen unrelated Japanese families with members clinically diagnosed with GEFSϩ or febrile seizures associated with afebrile seizures. Each participating subject or a responsible adult signed an informed consent form approved by the Ethics Review Committee of Fukuoka University or similar committees of the participating institutions. The proband of family K1 is a 6-yr-old boy with normal development (Fig. 1A). He had the first febrile seizure (FS) at 8 months of age and suffered 17 episodes of FS thereafter at both high and low grade fever. The FS were generalized tonic or tonic-clonic convulsions with duration of 1-5 min per episode. Since 4 yr of age, he also has experienced brief afebrile atonic seizures 5 times. The...