Fix Patches Track Settings
Reference Assembly Fix Patch Sequence Alignments   (All Mapping and Sequencing tracks)

Display mode:   

Color track by bases: Help on base coloring

Alignment Gap/Insertion Display Options Help on display options
Draw double horizontal lines when both genome and query have an insertion
Draw a vertical purple line for an insertion at the beginning or end of the
query, orange for insertion in the middle of the query
Draw a vertical green line where query has a polyA tail insertion
View table schema
Data last updated: 2018-11-06


This track shows alignments of fix patch sequences to main chromosome sequences in the reference genome assembly. When errors are corrected in the reference genome assembly, the Genome Reference Consortium (GRC) adds fix patch sequences containing the corrected regions. This strikes a balance between providing the most complete and correct genome sequence, while maintaining stable chromosome coordinates for the original assembly sequences.

Fix patches are often associated with incident reports displayed in the GRC Incidents track.

Display Conventions and Configuration

This track follows the display conventions for PSL alignment tracks. Mismatching bases are highlighted in red. Several types of alignment gap may also be colored; for more information, see Alignment Insertion/Deletion Display Options.


The alignments were provided by NCBI as GFF files and translated into the PSL representation for browser display by UCSC.