diff --git a/src/gene/etl/ncbi.py b/src/gene/etl/ncbi.py
index 4b0d8443..427d57e6 100644
--- a/src/gene/etl/ncbi.py
+++ b/src/gene/etl/ncbi.py
@@ -299,9 +299,7 @@ def _get_vrs_chr_location(self, row: List[str], params: Dict) -> List:
                 if chromosome == "MT":
                     params["location_annotations"].append(Chromosome.MITOCHONDRIA.value)
                 else:
-                    params["location_annotations"].append(
-                        Chromosome(chromosome.strip())
-                    )
+                    params["location_annotations"].append(chromosome.strip())
         elif locations:
             self._add_chromosome_location(locations, location_list, params)
         if not params["location_annotations"]:
diff --git a/src/gene/schemas.py b/src/gene/schemas.py
index 619bedfb..545588d4 100644
--- a/src/gene/schemas.py
+++ b/src/gene/schemas.py
@@ -47,30 +47,6 @@ class Annotation(str, Enum):
 class Chromosome(str, Enum):
     """Define string constraints for chromosomes."""
 
-    CHR1 = "1"
-    CHR2 = "2"
-    CHR3 = "3"
-    CHR4 = "4"
-    CHR5 = "5"
-    CHR6 = "6"
-    CHR7 = "7"
-    CHR8 = "8"
-    CHR9 = "9"
-    CHR10 = "10"
-    CHR11 = "11"
-    CHR12 = "12"
-    CHR13 = "13"
-    CHR14 = "14"
-    CHR15 = "15"
-    CHR16 = "16"
-    CHR17 = "17"
-    CHR18 = "18"
-    CHR19 = "19"
-    CHR20 = "20"
-    CHR21 = "21"
-    CHR22 = "22"
-    CHRX = "X"
-    CHRY = "Y"
     MITOCHONDRIA = "MT"