Electroclinical and cytogenetic features of epilepsy in cri-du-chat syndrome.

Cri-du-chat syndrome (CdCs) is caused by deletion in the short arm of chromosome 5, occurring in 1:15,000 to 1:50,000 live births. Recent genotype-phenotype correlation studies show the importance of 5p15.2 for facial dysmorphism and intellectual disability, and 5p15.3 for cat-like cry. Numerous reports have shown the relative rarity of epilepsy in this syndrome. We identified two cases with epilepsy in CdCs, and described their electroclinical and cytogenetic features. The first case was a 25-year-old female who had axial tonic seizures with flexion of the neck and shoulders. Interictal EEG was characterized by generalized spike-and-slow-wave complexes. Her ictal EEG started with diffuse electrodecremental pattern, followed by alpha-range activities. High-resolution banding analysis of chromosomes revealed a terminal deletion of 5p14.1. The second case was a 30-year-old female who had startle epilepsy with falling. Interictal EEG demonstrated generalized spike and slow waves. High-resolution banding analysis revealed a terminal deletion of 5p13.3 with additional chromosomal material of unknown origin. Based on the cases presented here, as well as those previously reported, the relationship between epilepsy and CdCs is discussed. The data suggests that although CdCs patients rarely suffer from epileptic seizures, the seizures may vary in type.