In order to determine how common sudden unexpected death from epilepsy (SUDEP) is in people with an extra isodicentric 15 chromosome (idic15), researchers studied approximately 709 families registered with the Dup15Q Alliance. Their case-control study found 19 deaths among patients with idic15, 17 of whom had epilepsy. Nine of these deaths were caused by probable or definite SUDEP; 2 others had what investigators considered possible SUDEP. Researchers concluded that SUDEP is common among children and young adults with duplications of the idic15 chromosome and that the risk of death is most likely to occur in patients with the most severe neurologic dysfunction.
Friedman D, Thaler A, Thaler J et al. Mortality in isodicentric chromosome 15 syndrome: the role of SUDEP. Epilepsy Behav. 2016;61:1-5.