In a missense gene mutation, a single portion of the gene's DNA is reconfigured so that certain amino acids which form the building blocks of proteins are replaced, one for another. This change can remove a protein's function or, theoretically, set off biological chain reactions that lead to disease.
In the case of RANBP2, researchers still need to find out if mutation causes disease susceptibility by disrupting the protein's primary functions or whether it triggers a new chain of biological events. They suspect the latter and plan in future research to investigate how the mutation may impact the function of mitochondria. Mitochondria are the specialized parts of the cell that control energy production.
Mutation of RANBP2 is not the only susceptibility gene for the disease, although researchers said it accounted for 75 percent of the cases of familial or recurrent cases in the current study, showing up in 12 of 16 families. The gene mutation in itself is insufficient to cause full-blown ANE1. Additional genetic and environmental factors such as the specific biological route the virus takes and a person's nutritional status may also be important considerations, the researchers said.
The study included nearly two hundred children and adults from 35 unrelated families, 50 of whom had confirmed episodes of ANE. Nineteen patients of European, Asian or African descent had isolated cases of ANE. None of the participants with isolated ANE, as well as over a thousand healthy control patients, carried the RANBP2 mutation. The rest of the participants came from 16 families of European descent affected by familial or recurrent forms of the disease.
In one family central to the current study, 16 fa
|Contact: Nick Miller|
Cincinnati Children's Hospital Medical Center