Approximately 10% of motor neuron disease (MND) patients report a familial predisposition for MND. Autosomal recessively inherited MND is less common and is most often caused by mutations in the superoxide dismutase 1 (SOD1) gene. In 2010, autosomal recessively inherited mutations in the optineurin (OPTN) gene were found in 1% of Japanese patients with sporadic amyotrophic lateral sclerosis (ALS). Autosomal dominantly inherited OPTN mutations have been described as a cause of primary open-angle glaucoma in the Netherlands and were also found in two Dutch sporadic MND patients. We report the first Dutch family with autosomal recessively inherited MND caused by mutations in the OPTN gene.