• POSTMORTEM
• NEUROPATHOLOGY
• AUTOPSY PATHOLOGY

The purpose of this letter is to present the extended autopsy protocol that allowed for recognition of cytochrome oxidase (COX) deficiency post mortem and subsequent identification of SCO2 mutations in an infant who died without established cause.

Mitochondrial pathology, including SCO2 deficiency, is a frequent cause of severe disease in neonates and infants. Due to the fast progression and early deaths, a completion of the final diagnosis in living patient is often impossible. The standard autopsy protocol usually does not substantially contribute to the appropriate diagnosis.

The SCO2 protein belongs to copper chaperones, which contribute to activation of COX. Classical phenotype of SCO2 deficiency includes neonatal mitochondrial encephalocardiomyopathy and is characteristic for compound heterozygotes of SCO2 gene mutations.1 The later onset of mitochondrial encephalomyopathy with expiratory stridor and respiratory failure is observed in g.1541G>A homozygotes.2 ,3

The patient presented at birth with a respiratory insufficiency and progressive neurological involvement. He died at the age of 3 months. Neither muscle biopsy nor a fibroblast culture was performed during the life. The autopsy was made at the regional hospital 37.5 h after death according to our recommendation.

The extended autopsy protocol included: (1) biochemical examination of frozen tissue sections taken at standard autopsy and (2) neuropathological examination of the brain.4 The study was approved by the CMHI bioethical committee. The patients’ parents provided written informed consent for the study.

Autopsy tissues of the patient were kept in deep-frozen condition. …