Familial ALS May Be More Common Than Previously Recognized

To quantify the risk for amyotrophic lateral sclerosis (ALS) among siblings and offspring of patients with apparently sporadic ALS, researchers examined data on 1622 siblings and 1545 offspring of patients diagnosed with ALS at one tertiary care clinic.

The overall crude incidence of ALS was 0.11% per year both among siblings and among offspring of patients with apparently sporadic ALS. The actual risk for ALS in siblings of patients with ALS was 2.4% by age 85. Although this risk was 8-fold higher than the local-population risk for ALS, the authors estimate that the probability of not developing ALS by age 85 among siblings of patients with ALS was still high: 97.6%, compared with 99.7% in the local general population.