THE X-LINKED INFANTILE SPASMS SYNDROME (MIM-308350) MAPS TO XP11.4-XPTER IN 2 PEDIGREES

We report 2 families with X-linked infantile spasms syndrome (X-linked West syndrome). Data from clinical examination, biochemical analysis, neuroimaging, and neuropathology are discussed. In these families, ge netic linkage analysis was able to locate the disease gene to the dist al part of the short arm of the X chromosome, between Xpter and Xp11.4 . This is the first report of linkage with genetic markers in this dis order. Although most cases are sporadic, further unraveling of the gen etic background of the familiar cases might greatly improve our unders tanding of infantile spasms.