PT - JOURNAL ARTICLE AU - Susan Byrne AU - Cathal Walsh AU - Catherine Lynch AU - Peter Bede AU - Marwa Elamin AU - Kevin Kenna AU - Russell McLaughlin AU - Orla Hardiman TI - Rate of familial amyotrophic lateral sclerosis: a systematic review and meta-analysis AID - 10.1136/jnnp.2010.224501 DP - 2011 Jun 01 TA - Journal of Neurology, Neurosurgery & Psychiatry PG - 623--627 VI - 82 IP - 6 4099 - http://jnnp.bmj.com/content/82/6/623.short 4100 - http://jnnp.bmj.com/content/82/6/623.full SO - J Neurol Neurosurg Psychiatry2011 Jun 01; 82 AB - Background The population rate of familial amyotrophic lateral sclerosis (FALS) is frequently reported as 10%. However, a systematic review and meta-analysis of the true population based frequency of FALS has never been performed.Method A Medline literature review identified all original articles reporting a rate of FALS. Studies were grouped according to the type of data presented and examined for sources of case ascertainment. A systematic review and meta-analysis of reported rates of FALS was then conducted to facilitate comparison between studies and calculate a pooled rate of FALS.Results 38 papers reported a rate of FALS. Thirty-three papers were included in analysis and the rate of FALS for all studies was 4.6% (95% CI 3.9% to 5.5%). Restricting the analysis to prospective population based registry data revealed a rate of 5.1% (95% CI 4.1% to 6.1%). The incidence of FALS was lower in southern Europe. There was no correlation between rate of FALS and reported SOD1 mutation rates.Conclusion The rate of FALS among prospective population based registries is 5.1% (CI 4.1 to 6.1%), and not 10% as is often stated. Further detailed prospective population based studies of familial ALS are required to confirm this rate.