Cavitating leukoencephalopathy with multiple mitochondrial dysfunction syndrome and NFU1 mutations.

Area of Science:

• Biochemistry
• Genetics
• Neurology

Background:

• Multiple Mitochondrial Dysfunction Syndrome (MMDS) is a group of severe, early-onset autosomal recessive disorders.
• MMDS is characterized by systemic energy metabolism defects, leading to weakness, respiratory failure, developmental delay, lactic acidosis, and early mortality.
• Biochemical hallmarks include mitochondrial respiratory chain complex deficiencies and pyruvate dehydrogenase complex (PDHc) deficiency.

Observation:

• A case study of an Italian male infant with severe psychomotor regression following an infection.
• Clinical presentation included lactic acidosis, hyperglycinemia, reduced Complex II activity, and marked PDHc deficiency.
• Brain MRI revealed severe leukoencephalopathy with white matter cavitations.

Findings:

• The patient carried two heterozygous mutations in the NFU1 gene: one novel (p.Cys210Phe) and one previously reported (p.Gly189Arg) missense mutation.
• Both mutations affect highly conserved residues, suggesting functional impact.
• The findings link NFU1 gene mutations to a specific neuroradiological phenotype.

Implications:

• This study expands the known genetic basis of MMDS by identifying novel mutations in NFU1.
• It highlights a distinct neuroimaging phenotype associated with NFU1 defects.
• Further research into NFU1 function is warranted for understanding MMDS pathogenesis and developing therapeutic strategies.