`disgenet_info_filtered.pkl` is a pickled pandas DataFrame containing disease descriptions sourced from:
 - UMLS
 - OrphaNet (via PrimeKG)
 - MONDO (via PrimeKG)

Columns are:
 - index - unique identifier for this disease / UMLS concept ID in the txPLM datasets
 - disgenet_id - UMLS ID
 - various columns named by the sources of the description
 - allDescriptions - concatenation of all descriptions in the other columns
 - numDescriptions - total number of unique free text descriptions for this concept ID

Descriptions are concatenated with the `|` symbol, both within one source in the case of multiple
descriptions from one source, or across all sources in the `allDescriptions` column.

For more details, see the notebook at `../disgenet_curation.ipynb`.