Electro-clinical phenotypes of chromosome disorders associated with epilepsy in the absence of dysmorphism

Ring chromosome 20 syndrome: A link between epilepsy onset and neuropsychological impairment in three children

“…In the interictal period, EEG showed the persistence of frontal anomalies in all patients. The new‐onset fears, which appeared concomitantly with seizures, as well as the terrifying hallucinations reported in other patients (Canevini et al., 1998; Macleod et al., 2005; Ville et al., 2006) should be considered as part of the ictal symptoms.…”

“…Electroclinical phenotype of [r(20)] syndrome may be various. Until now, in several children the relationship between epilepsy and mental deterioration has been reported (Inoue et al., 1997; Canevini et al., 1998; Petit et al., 1999; Augustijn et al., 2001; Tanaka et al., 2004; Locharernkul et al., 2005; Macleod et al., 2005; Nishiwaki et al., 2005; Ville et al., 2006), but the link between the dramatic epilepsy onset and neuropsychological impairment has not been fully characterized.…”

“…Augustijn et al. (2001) and Macleod et al. (2005) have described eight children with [r(20)] syndrome who showed mental deterioration and frequent seizures associated with NCSE.…”

Genetic evaluation and counseling for epilepsy

“…of note, some of these chromosomal rearrangements might be present in patients with epilepsy who display an absence of cognitive impairment or obvious dys morphism. 54 thus, children with seizures who exhibit mild or moderate mental retardation and/or minor dysmorphic features should have an initial genetic evaluation consisting of karyo typing, chromosome microarray analysis, fragile X testing, and determination of organic acid levels in urine and amino acid levels in serum. Furthermore, children with epilepsies who do not easily fit a syndromic classification, especially those indivi duals whose epilepsy is intractable and nonlesional, warrant karyotyping and chromosome micro array analysis before a more-intensive or more-invasive evaluation.…”

“…Furthermore, children with epilepsies who do not easily fit a syndromic classification, especially those indivi duals whose epilepsy is intractable and nonlesional, warrant karyotyping and chromosome micro array analysis before a more-intensive or more-invasive evaluation. 54 idiopathic syndromes in the past decade, important discoveries have been made in the genetics of several rare mendelian epilepsy syndromes, including benign neonatal familial convulsions, 55,56 autosomal dominant nocturnal frontal lobe epilepsy (aDnFle) 57 and autosomal dominant partial epilepsy with auditory features. 58 these discoveries have led to improved genetic counseling for these syndromes, the indications for which are discussed elsewhere.…”