Trisomy 12p syndrome: a chromosomal disorder associated with generalized 3-Hz spike and wave discharges.
Three cases (2 boys, 1 girl) of trisomy 12p syndrome are reported. In two, the disorder is caused by a malsegregation of a maternal translocation, the karyotype being 46,XY,der(18),t(12;18)(p11;q23) (case 2) and 46,XX,-10,+ der(10),t(10;12)(p15;p11) (case 3). Case 1 is a de novo case with a regular trisomy 12p in the fibroblasts: 47,XY + (12pter----12 cen. . .?) and a mosaic trisomy 12p in lymphocytes: 46,XY/47,XY, + (12pter----12 cen. . .?). In all cases, the EEG showed 3-Hz generalized spike and wave (SW) discharges. Generalized epilepsy with myoclonic seizures was present in two patients (cases 1 and 2), who may be considered to have a symptomatic generalized epilepsy with a specific etiology. Case 3 has shown only febrile seizures. Any association between the excess of genetic material and the EEG trait "generalized SW" might not be a chance occurrence in this disorder; however, both EEG findings and clinical features (seizure type and frequency) in the 23 cases reported in the literature are too scanty to allow confirmation of such an association.
Guerrini
R
R
Centre Saint Paul, Marseille, France.
Bureau
M
M
Mattei
M G
MG
Battaglia
A
A
Galland
M C
MC
Roger
J
J
D001921:Brain / Q000503:physiopathology*; D002675:Child, Preschool; D002881:Chromosomes, Human, Pair 12; D004569:Electroencephalography; D004827:Epilepsy / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D003294:Seizures, Febrile / Q000235:genetics* / Q000503:physiopathology; D014314:Trisomy