is that a sizeable list you are talking about? is it from a single species or multiple?

what I'm kinda steering at is can't you simply extract that data from the refseq genome annotation files?

In this RefSeq genome annotation file, for example for IL9R we have different exons in different transcripts, some are shared and some unique. I would like to have a single line per gene with the union of exon coordinates:

results:

IL9R chrX
155997580,156002905,156003448,156003676,156004419,156005277,156006082,156007522,156009815,156001407,156002881...
155997787,156003019,156003560,156003855,156004565,156005479,156006188,156007607,156010817,156001508,156003019.

..

starting file:

1775    NM_002186.2 chrX    +   155997580   156010817   155997759   156010409   9   155997580,156002905,156003448,156003676,156004419,156005277,156006082,156007522,156009815,  155997787,156003019,156003560,156003855,156004565,156005479,156006188,156007607,156010817,  0   IL9R    cmpl    cmpl    0,1,1,2,1,0,1,2,0,
1775    NM_176786.1 chrX    +   155997580   156010817   155997743   156009852   9   155997580,156001407,156002881,156003448,156003683,156004448,156005277,156006082,156009815,  155997787,156001508,156003019,156003560,156003855,156004565,156005479,156006188,156010817,  0   IL9R    cmpl    cmpl    0,2,1,1,2,0,0,1,2,

thanks