Parents

The NUBPL gene encodes one of several proteins that function in the mitochondria to produce the energy fueling cells in the body. Part of this process involves the electron transport chain, which is comprised of four large complexes labeled I to IV. The NUBPL protein, along with 43 other proteins (encoded by other genes), form complex I. Therefore, mutations in these genes cause mitochondrial disease of the subtype called Complex I deficiency. Complex I deficiency disorders are recessive, meaning that both copies of the gene – one inherited from the mother and one inherited from the father – need to contain a damaging mutation in order for the child to have this genetic disease. The main clinical features of NUBPL complex I deficiency, which usually begin around 3-18 months of age, are global developmental delay that includes problems with walking and fine motor control as well as slurred or slowed speech.