title: Autosomal dominant early-onset cortical myoclonus, photic-induced myoclonus, and epilepsy in a large pedigree.
abstract: OBJECTIVE
  Cortical tremor, a form of rhythmic cortical myoclonus (rhythmic CM), and epilepsy have been described in families with autosomal dominant inheritance. Linkage analyses revealed two putative loci on chromosome 2p and 8q. Clinical photosensitivity was not a prominent feature in such families. We describe a large Italian family with rhythmic CM, photosensitivity, and epilepsy.
  
  
  METHODS
  Twenty-three individuals of a five-generation family were studied. Linkage analyses for the loci on chromosome 2p11.1 and 8q23.3 were performed.
  
  
  RESULTS
  Of the 23 studied family members, 16 were affected. Rhythmic CM of childhood onset was present in all 16 individuals (onset ranging from 3 to 12 years), was associated with photic-induced myoclonic jerks in seven, and with epileptic seizures in six (onset ranging from 23 to 34 years). Five children of the V generation manifested also episodes of arousal with generalized tremor in early infancy ("tremulous arousals"). Jerk-locked back-averaging of rhythmic CM of six affected individuals, documented a premyoclonic EEG correlate. C-reflex at rest was present in two affected adults. Linkage analyses excluded mapping to the 2p11.1 and 8q23.3 loci.
  
  
  CONCLUSIONS
  Clinical variability and severity of the phenotypes in this family are in line with those of previously described pedigrees with autosomal dominant cortical myoclonus and epilepsy. In this family, a progression of symptoms was found: rhythmic CM and tremulous arousals occurred in childhood, whereas visually induced manifestations and epileptic seizures occurred during adolescence-adulthood. Exclusion of linkage to the two known loci is consistent with genetic heterogeneity of such familial clustering of symptoms.
authors.affiliation: Department of Neurosciences, Bellaria Hospital, Clinica Neurologica, Bologna, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Gardella
authors.forename: Paolo
authors.initials: P
authors.lastname: Tinuper
authors.forename: Carla
authors.initials: C
authors.lastname: Marini
authors.forename: Renzo
authors.initials: R
authors.lastname: Guerrini
authors.forename: Elena
authors.initials: E
authors.lastname: Parrini
authors.forename: Francesca
authors.initials: F
authors.lastname: Bisulli
authors.forename: Rocco
authors.initials: R
authors.lastname: Liguori
authors.forename: Pasquale
authors.initials: P
authors.lastname: Montagna
authors.forename: Elio
authors.initials: E
authors.lastname: Lugaresi
mesh_terms: D017668:Age of Onset; D001927:Brain Diseases / Q000235:genetics* / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics; D004827:Epilepsy / Q000235:genetics*; D020195:Epilepsy, Reflex / Q000235:genetics; D008040:Genetic Linkage; D006801:Humans; D009207:Myoclonus / Q000235:genetics* / Q000503:physiopathology; D010375:Pedigree