[A case of West syndrome with a deletion at chromosome 2q24.3-q31.3]

A male infant suffered from partial seizures at four months of age, and developed West syndrome at eight months of age. ACTH therapy was effective for the West syndrome. However, partial seizures recurred at 14 months of age, which could not be sufficiently controlled with an anti-epileptic drug. A characteristic facial appearance, great toe abnormalities, and developmental retardation were noted. An interstitial deletion of 2q was detected by chromosomal G-banding and array comparative genomic hybridization (CGH) confirmed the deletion as arr 2q24.3q31.3 (166,303,447-180,982.972) ×1 (build19). He presented with clinical findings similar to those of the recently defined 2q31.1 deletion syndrome. The deletion extended to the SCN1A gene, a gene responsible for Dravet syndrome, mapped to the 2q24.3 region. No deletion was noted in the adjacent SCN2A gene. Thus, for interstitial deletions, detailed breakpoints should be identified by array CGH. The frequency of epilepsy varies with deletion ranges in the 2q24-q31 region, suggesting that deletions in the SCN1A gene deletion, as well as in the 2q31.1 region, are involved in the development of West syndrome.