Myoclonal Epilepsy and Ragged Red Fiber Disease (MERRF) Is a Human

Multiple Choice

Myoclonal epilepsy and ragged red fiber disease (MERRF) is a human condition named for the ragged red fibers of skeletal muscle cells and myoclonic epilepsy in affected individuals. People with this disorder have a mutation in a mitochondrial gene for a tRNA, specifically that for lysine. Affected individuals are heteroplastic. Why?

A) Mutations of this gene are dominant.
B) Mutations of this gene affect individuals before birth.
C) Interference with translation is not fully rescued by importing lysine from the cytoplasm.
D) Lysine is required in translation of every one of the mitochondrial genes.
E) Homoplastic organelles would be inviable due to failures in translation.