diff --git a/scout/adapter/mongo/case.py b/scout/adapter/mongo/case.py
index <HASH>..<HASH> 100644
--- a/scout/adapter/mongo/case.py
+++ b/scout/adapter/mongo/case.py
@@ -87,6 +87,7 @@ class CaseHandler(object):
             updated_case(dict)
         """
         dynamic_gene_list = []
+        res = []
         if hgnc_ids:
             logger.info("Fetching genes by hgnc id")
             res = self.hgnc_collection.find(
Fixes problem when updating dynamic gene list

There was a unbound local variable error when no hgnc genes where found