1. Academic Validation
  2. Mutations of the SCO1 gene in mitochondrial cytochrome c oxidase deficiency with neonatal-onset hepatic failure and encephalopathy

Mutations of the SCO1 gene in mitochondrial cytochrome c oxidase deficiency with neonatal-onset hepatic failure and encephalopathy

  • Am J Hum Genet. 2000 Nov;67(5):1104-9. doi: 10.1016/S0002-9297(07)62940-1.
I Valnot 1 S Osmond N Gigarel B Mehaye J Amiel V Cormier-Daire A Munnich J P Bonnefont P Rustin A Rötig
Affiliations

Affiliation

  • 1 Unité de Recherches sur les Handicaps Génétiques de l'Enfant, INSERM U-393, Hôpital Necker-Enfants Malades, 75743 Paris, France.
Abstract

Cytochrome c oxidase (COX) catalyzes both electron transfer from cytochrome c to molecular oxygen and the concomitant vectorial proton pumping across the inner mitochondrial membrane. Studying a large family with multiple cases of neonatal ketoacidotic comas and isolated COX deficiency, we have mapped the disease locus to chromosome 17p13.1, in a region encompassing two candidate genes involved in COX assembly-namely, SCO1 and COX10. Mutation screening revealed compound heterozygosity for SCO1 gene mutations in the patients. The mutated allele, inherited from the father, harbored a 2-bp frameshift deletion (DeltaGA; nt 363-364) resulting in both a premature stop codon and a highly unstable mRNA. The maternally inherited mutation (C520T) changed a highly conserved proline into a leucine in the protein (P174L). This proline, adjacent to the CxxxC copper-binding domain of SCO1, is likely to play a crucial role in the tridimentional structure of the domain. Interestingly, the clinical presentation of SCO1-deficient patients markedly differs from that of patients harboring mutations in other COX assembly and/or maturation genes.

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