Epilepsy, Juvenile Myoclonic, Susceptibility To, 9

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Retrieved

2019-09-22

Source

Omim

Trials

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Genes

EFHC1, GABRA1, CACNB4, JRK, KCNQ3, CLCN2, GABRD, CILK1, BRD2, CTF1, CHRNA4, EJM2, GABRG2, GJD2, GRM4, SCN1A, CSTB, GABRB3, SEC14L2, ME2, CHRNA7, KCNQ2, KCND3, TRPM2, IGHE, TAP1, EFHC2, GJA8, GABBR1, REM1, RMDN1, PADI4, LGSN, BCL9, SLC12A5, RMDN3, LRRC1, SYBU, CPA6, CLOCK, MMEL1, DHX40, NPL, CHRFAM7A, RBM45, RMDN2, MED19, SLC12A6, SELENOP, ABCG2, KCNJ3, CASR, DNMT1, ATN1, EXT1, F2, GABRA5, HLA-DPB1, HLA-DQA1, HLA-DRB1, HLA-F, KCNJ6, TOP3B, CFP, ABCB1, PLXNB1, HCN2, SLC6A4, SLC12A2, TFAP2B, ALDH5A1, PER3, PER2, STIN2-VNTR

Drugs

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For general phenotypic information and a discussion of genetic heterogeneity of juvenile myoclonic epilepsy, see 254770.

Clinical Features

Ratnapriya et al. (2010) reported a 4-generation family from southern India in which 6 living members had juvenile myoclonic epilepsy. Age at onset ranged from 12 to 20 years, and all had myoclonic seizures with secondary generalized tonic-clonic seizures. Two patients had a history of febrile seizures, and 2 had absence seizures. EEG showed generalized 4-6 Hz polyspike and wave discharges characteristic of a generalized epilepsy. Features included repetitive myoclonic seizures involving upper extremities, often after awakening, and at least 1 patient reported that seizures were precipitated by alcohol, sleep deprivation, and flashing lights. Three patients exhibited a photoparoxysmal response. Two clinically unaffected individuals had an abnormal EEG.

Inheritance

The transmission pattern of juvenile myoclonic epilepsy in the family reported by Ratnapriya et al. (2010) was consistent with autosomal dominant inheritance.

Mapping

By genomewide linkage analysis followed by fine-mapping of an Indian family with juvenile myoclonic epilepsy, Ratnapriya et al. (2010) identified a locus on chromosome 2q33-q36 (maximum 2-point lod score of 3.32 at D2S2248, multipoint lod score of 3.59 for the region between D2S2322 and D2S2228). Haplotype analysis delineated a 29-cM candidate region between markers D2S116 and D2S2390 on chromosome 2q33-q36. No mutations were detected in the SLC4A3 (106195), SLC11A1 (600266), SLC23A3, or KCNE4 (607775) genes.