GENEVA-Genetic factors may have contributed to a spike in narcolepsy cases observed among children in Finland who received the swine flu vaccine Pandemrix, the World Health Organization said Tuesday.
A WHO expert panel says of 22 narcolepsy patients tested, all had a gene commonly associated with narcolepsy, a disorder that causes people to suddenly fall asleep but is rarely fatal.
About 30 percent of people in Finland have that particular gene, compared with 15 percent in the rest of Europe, said Patrick Zuber, WHO's top vaccine safety official.
Last week, Finnish authorities said they had found a nine-fold increased risk of narcolepsy among 4- to 19-year-olds who were given the swine flu shots. In total, 60 children and adolescents contracted narcolepsy in Finland in 2009 and 2010. Fifty-two of them-or almost 90 percent-had received the Pandemrix vaccine.