2.2 years ago by
Having looked into this problem- it's caused by the way that retired Ensembl stale IDs are labelled in our database. This means that the ID history convertor does not recognise retired stable IDs and simply lists the retired stable ID for the current Ensembl release.
This is only a problem where an old stable ID is not linked to a new stable ID. Where an old stable ID is linked to a stable ID in the current version of Ensembl, the ID history convertor will be able to provide an accurate history.
With ENSGALG00000015646, you have found an example where the ID is retired and not mapped to a gene in the current version of Ensembl. This happens in the instances where the mapping pipeline does not detect a sufficiently similar gene.
To fix this, we will change the way stable IDs are retired in our database, so that the results the ID history convertor provides for retired stable IDs is not ambiguous. However, we are unable to change the pipeline that maps the stable IDs, and so from Ensembl 91 onwards you will see ENSGALG00000015646 simply listed as 'retired'.
I hope this helps clarify the data you retrieved form the ID history convertor, but please do get back in touch if anything is still unclear.