Complex III (CIII; ubiquinol @entity4674 reductase of the mitochondrial respiratory chain) catalyzes electron transfer from @entity4588 and @entity2125 -linked dehydrogenases to @entity4674 . CIII is made up of 11 subunits, of which all but one ( @entity13508 ) are encoded by nuclear DNA. @entity6345 are rare and manifest heterogeneous clinical presentations. Although pathogenic mutations in the gene encoding mitochondrial @entity13508 have been described, mutations in the nuclear-DNA-encoded subunits have not been reported. Involvement of various genes has been indicated in assembly of @entity375 CIII (refs. 8-11). So far only one such gene, @entity35506 , has been identified in @entity1 . @entity35506 represents, therefore, an obvious candidate gene in @entity6345 . Here, we report @entity35506 mutations in six @entity1 , from four unrelated families and presenting neonatal proximal @entity8 , hepatic involvement and @entity75 . Complementation study in @entity375 confirmed the deleterious effect of these mutations. Mutation of @entity35506 would seem to be a frequent cause of @entity6345 , as one-third of our @entity1 have @entity35506 mutations.

A mutant mitochondrial respiratory chain assembly protein causes @entity6345 in @entity1 with XXXX , @entity75 and liver failure.

@entity1 :: ('9606', 'Species') :: ['human', 'patients'] @entity2125 :: ('MESH:D009243', 'Chemical') :: ['nicotinamide adenine dinucleotide'] @entity8 :: ('MESH:D007674', 'Disease') :: ['tubulopathy'] @entity4588 :: ('MESH:D019802', 'Chemical') :: ['succinate'] @entity4674 :: ('54205', 'Gene') :: ['cytochrome c'] @entity35506 :: ('617', 'Gene') :: ['BCS1L'] @entity75 :: ('MESH:D001927', 'Disease') :: ['encephalopathy'] @entity13508 :: ('4519', 'Gene') :: ['cytochrome b'] @entity6345 :: ('MESH:C565128', 'Disease') :: ['CIII deficiencies', 'CIII deficiency'] @entity375 :: ('4932', 'Species') :: ['yeast']
@entity8 :: (MESH:D007674,Disease) :: ['tubulopathy']
