Action Myoclonus and Seizure in Kufor-Rakeb Syndrome.

Kufor-Rakeb syndrome (KRS) is a rare autosomal recessive neurologic disease with diverse phenotypic features. Herein we report an Iranian KRS family with seizure and action myoclonus in addition to other typical manifestations of this syndrome.

All family members underwent careful neurologic examination. Exome sequencing was performed and ATP13A2 variation genotyped in all family members.

Cognitive deficits, hypokinesia, rigidity, spasticity, brisk deep tendon reflexes, upward gaze palsy, tremor, and facial-faucial-finger mini-myoclonus were the common manifestations of all affected siblings. Two cases had seizure and the most severely affected sibling demonstrated severe action myoclonus. Exome sequencing identified a homozygous nonsense mutation c.2455C>T;p.Arg819* in ATP13A2 gene.

We reported five KRS affected siblings who manifested myoclonus and seizure. The most severely affected one demonstrated action myoclonus, which has not been reported so far.