Complex I deficiency is a mitochondrial disorder caused by mutations in 1 of 34 genes that encode proteins required to form the first large enzyme complex (complex I) of the energy-producing electron transport chain. In 2010, the first case of autosomal recessive NUBPL disease was reported. We report the clinical features and mutations in four new patients with NUBPL disease and summarize findings in all known cases (now eighteen worldwide). The disease begins in infancy with neurological impairments such as tremor, uncontrolled eye movements, and difficulties with sitting up, walking, and speech. Many patients are likely undiagnosed because a common mutation (~1% frequency in the European ancestry population) may be overlooked in clinical sequencing tests. (By Dr. Peggy S. Eis, https://jmg.bmj.com/content/early/2020/06/09/jmedgenet-2020-106846 )

TWO NUBPL FAMILIES MEET FOR FIRST TIME, 2,000 MILES APART