Congenital Hypermetabolism and Uncoupled Oxidative Phosphorylation.

Area of Science:

• Biochemistry
• Genetics
• Mitochondrial Biology

Background:

• Mitochondrial ATP synthase (Complex V) is crucial for cellular energy production.
• Disruptions in mitochondrial function can lead to various metabolic disorders.

Observation:

• Identical twin boys presented with failure to thrive, characterized by low body weight despite excessive caloric intake.
• Fibroblast analysis revealed heightened oxygen consumption and diminished mitochondrial membrane potential in the affected individuals.

Findings:

• Exome sequencing identified a de novo heterozygous variant in ATP5F1B, encoding the beta subunit of ATP synthase.
• This variant, when expressed in human cell lines, replicated the observed mitochondrial dysfunction.
• Functional studies in yeast indicated that mutations in this region uncouple proton flow from ATP synthesis, increasing respiration rates.

Implications:

• These findings identify a novel autosomal dominant mitochondrial uncoupling syndrome associated with hypermetabolism.
• This research sheds light on the genetic basis of unexplained pediatric weight loss and metabolic derangements.
• Understanding this mechanism may offer new therapeutic targets for metabolic disorders.