Gene: SCO2
Protein: Protein SCO2 homolog, mitochondrial
Clinical characteristics:
- Hypertrophic cardiomyopathy, onset may be several months after birth
- Encephalopathy or Leigh syndrome (subacute necrotizing encephalopathy)
- Lactic acidosis
- Muscle biopsy findings
- Decreased activity of cytochrome c oxidase (COX deficiency)
- Neurogenic changes or SMA-like pattern of muscle fibers
- Hypotonia
- Respiratory difficulty and/or inspiratory stridor
- Developmental delay
- Spasticity or seizures
- Decreased extraocular movement (ptosis, strabismus)
- History of miscarriages or stillbirths
Inheritance pattern: Autosomal recessive
What this test can tell us:
Testing is performed by sequencing the entire coding region (exon 2) and surrounding intronic regions of SCO2. This will detect point mutations, small deletions, and small insertions. It will not detect a partial or whole gene deletion or duplication.
A negative test does not rule out a genetic cause of COX deficiency or a neuromuscular disorder, as there are many other genes, both nuclear and mitochondrial, associated with different types of neuromuscular disorders.
Sample requirements: Draw one or two 4-cc tubes of blood in EDTA/ purple top tube (minimum of 1-2 cc for infants)
Turn-around time: 10-14 days
CPT codes and cost:
83891 (x1) 83898 (x2) 83904 (x3) 83912 (x1) $ 150
Fatal Infantile Cardioencephalomyopathy Due to Cytochrome C Oxidase Deficiency Testing Packet