improve NameChecker c.3217insT error
Created by: jtdendunnen
Using NM_000492.3:c.3217insT in the NameChecker gives: The "^" indicates the position where the error occurred.
Suggest to make the error message more informative, e.g.; The "^" indicates the position where the error occurred. An insertion must be BETWEEN two flanking nucleotides, e.g. NM_004006.2:c.123_124insG.