[A case of familial hypokalemic periodic paralysis with hyperuricemia during paralytic attack and genetic analysis of the pedigree].

We reported a 13-year-old boy and his family with hypokalemic periodic paralysis. He showed marked hyperuricemia during his paralytic attack, although neither ischemic forearm exercise test nor bicycle-ergometer exercise test revealed myogenic hyperuricemia when he was free from paralysis. Genetic analysis was performed to the proband and his affected elder brother, mother, and, maternal grand mother. We found the Arg528His mutation of CACNL1A3 gene in all the patients examined. The severity of the attacks and the age of onset did not vary in the different generations, and male predominancy was not evident in this family.