The paper by Jennifer Jaskiewicz and colleagues  recently offered a further important insight into the relationship between autism and seizure or seizure disorder (i.e. epilepsy).
Based on the examination of records of nearly 50,000 children and young adults diagnosed with an autism spectrum disorder (ASD) compared with approximately quarter of a million 'not-autism' participants, authors reported some interesting trends. Concluding that some 19% of participants with autism experienced "some kind of seizure or seizure disorder", the study in particular reaffirms something of an important relationship between [some] autism and [some] epilepsy or seizure disorder.
Drawing on data derived from the US Military Health System database between 2000-2013, the records of children and young adults aged 0-18 years were the focus of analysis, where those with autism were age and sex-matched with asymptomatic (not autism) controls. Alongside the heightened risk of a general description of 'seizure or seizure disorder' in the autism group, authors also reported that specific issues such as status epilepticus and absence seizures were over-represented in the autism group. Febrile seizures - seizures that accompany fever - were also over-represented in the autism group although to a slightly lower extent than other seizure types. The authors conclude that: "Rates of epilepsy in children with autism are vastly increased in a wide variety of seizure types, known to have different etiologies, genetic and otherwise." Compare also the estimate of epilepsy or seizure disorder shown here with other population figures  and you get a flavour for how advanced the risk might be...
 Jaskiewicz J. et al. Quantification of Risks of Seizure in Autism. Neurology. 2016; 86: suppl. S32.003.
 Russ SA. et al. A national profile of childhood epilepsy and seizure disorder. Pediatrics. 2012 Feb;129(2):256-64
Jennifer Jaskiewicz, Apryl Susi, Elizabeth Hisle-Gorman, David Dennison, Gregory Gorman, Cade Nylund, & Christine Erdie-Lalena (2016). Quantification of Risks of Seizure in Autism Neurology