ADARB1 and Encephalopathy: Similarly, heterozygous ADARB1 variants did not lead to epilepsy in the subjects of the above-mentioned study, whereas biallelic variants resulted in a severe encephalopathy.10 In agreement with these observations, the loss-of-function observed/expected upper bound fraction is 0.4 and ADARB1 is predicted to be likely associated with a recessive rather than a dominant disorder by DOMINO.19