Overview
Genetic mutations can influence how a protein behaves in a cell, not just whether it is present, but how much of it is produced, how active it is, or what it does. Gain-of-function mutations enhance normal activity or create new functions, while loss-of-function mutations reduce or eliminate normal gene product function.
Frequently Asked Questions
Can the same mutation be both gain- and loss-of-function?
Not the same mutation, but different mutations in the same gene can have opposite effects, one increasing protein activity, another eliminating it.
How do researchers determine if a mutation is gain-of-function or loss-of-function?
Researchers use biochemical assays, signaling readouts, and phenotype characterization in cell or mouse models to assess whether a mutation increases, reduces, or abolishes function.