I have an abnormality in the circuits for language output, and sure enough, as a child I had trouble getting language out.
A post mortem examination revealed that there were no obvious signs of abnormality in Miss Moss' body.
But apparently there was just an “‘abnormality’ in the system.”
abnormality ab·nor·mal·i·ty (āb'nôr-māl'ĭ-tē)
An anomaly, malformation, or difference from the normal.