SCO2 Mutation Analysis
The cytochrome c oxidase complex is composed of 13 subunits that reside in the inner mitochondrial membrane. Three of these subunits, which form the catalytic core of the complex, are encoded by mitochondrial DNA, whereas the remaining ten subunits are encoded by nuclear DNA. COX catalyzes the terminal step in electron transport, resulting in the reduction of molecular oxygen by reduced cytochrome c. Multiple mutations have been identified in several COX subunits, including all three mitochondrial-encoded subunits, resulting in COX deficiency and disease. Mutations in SCO2, which functions in mitochondrial copper delivery, have been identified in patients with fatal, infantile hypertrophic cardiomyopathy with encephalopathy.
SCO2 Copper Transport
SCO2 is composed of two exons. However, only exon 2 contains protein-coding sequence. A variety of autosomal recessive SCO2 mutations, including nonsense, missense and small duplication mutations, have been described in infantile hypertrophic cardiomyopathy patients with encephalopathy.
The John Welsh Cardiovascular Diagnostic Laboratory offers molecular genetic testing for SCO2 mutations. Symptomatic individuals are tested by automatic fluorescent DNA sequencing of exon 2 of the SCO2 gene. Genetic counseling is recommended for all individuals and their families.
Reasons for Referral
Molecular confirmation of the diagnosis of severe infantile hypertrophic cardiomyopathy with encephalopathy resulting from SCO2 mutations.
Genomic DNA is analyzed for SCO2 mutations by automatic fluorescent DNA sequencing of exon 2 of the SCO2 gene, as well as the intron 1/exon 2 splice junction, and a portion of the 3′ untranslated region. Patient DNA is sequenced in both the forward and reverse orientations.
|Service||Direct and Institutional Billing||CPT Codes|
|Index Case (Male or Female)||$300 per sample||81403, G0452|
|Additional Family Members||$300 per sample; known familial mutation only||81403, G0452|
DNA Sequencing Analysis: Approximately 99 percent detection of mutations in exon 2 of SCO2.
Blood (preferred): EDTA (purple-top) tubes: Adult: 5 cc, Child: 5 cc, Infant: 2-3 cc
Tissue: Frozen (preferred), RNAlater, Formalin-fixed, Paraffin-embedded
Other Body Fluids: Call to inquire
Buccal Swabs: One swab from each cheek