Epilessia focale con marcata attivazione delle anomalie EEG in sonno in paziente con Sindrome di Klinefelter e delezione 9q34

Epilepsy with benign course or age-dependent epileptic encephalopathies are common in chromosomal abnormalities; epilepsy in Klinefelter's syndrome usually runs a benign course. The chromosome 9q subtelomeric deletion syndrome, caused by haploinsufficiency of EHMT1 gene, is characterized by severe mental retardation, hypotonia, brachi-microcephaly, specific dimorphisms, congenital heart defects and epilepsy; in this syndrome seizures are usually controlled with standard AED and may improve with age. We report a male patient with 47,XXY karyotype and terminal deletion of chromosome 9q34.3. The boy suffered by epileptic encephalopathy: focal seizures and subcontinuous epileptic discharges during sleep were concomitant with language regression. The mother and the young sister, now aged 6 months, carried the same 9q34.3 deletion; the mother never experienced seizures and only has mild cognitive deficit. The description of this family contributes to the delineation of the 9q deletion electroclinical phenotype.