CLN5 and juvenile neuronal ceroid lipofuscinosis: Over 5 assessments from 5 to 18 months, sheep with CLN5 Batten disease who received moderate‐dose scAAV9/oCLN5 gene therapy pre‐symptomatically exhibited “control‐like” patterns of brain change, strikingly different from the accelerated pattern of atrophy exhibited by untreated affected sheep.