De novo mutations in KIF1A cause progressive encephalopathy and brain atrophy.

Objective: To determine the cause and course of a novel syndrome with progressive encephalopathy and brain atrophy in children.

Methods: Clinical whole-exome sequencing was performed for global developmental delay and intellectual disability; some patients also had spastic paraparesis and evidence of clinical regression. Six patients were identified with de novo missense mutations in the kinesin gene KIF1A.