Supporting population allele frequencies

common/file_model/populations.json

@@ -0,0 +1,34 @@
+{
+   "1000_genomes": [
+   {"name": "1000GENOMES:phase_3:ALL", "frequencies": {"af": "AF"}}, 
+   {"name": "1000GENOMES:phase_3:AFR", "frequencies": {"af": "AFR_AF"}},
+   {"name": "1000GENOMES:phase_3:AMR", "frequencies": {"af": "AMR_AF"}},
+   {"name": "1000GENOMES:phase_3:EAS", "frequencies": {"af": "EAS_AF"}},
+   {"name": "1000GENOMES:phase_3:EUR", "frequencies": {"af": "EUR_AF"}},
+   {"name": "1000GENOMES:phase_3:SAS", "frequencies": {"af": "SAS_AF" }}
+   ],
+   "gnomAD_exomes": [
+    {"name": "gnomADe:ALL", "frequencies": {"af": "gnomAD_exomes_AF", "ac": "gnomAD_exomes_AC", "an": "gnomAD_exomes_AN"}},
+    {"name": "gnomADe:afr", "frequencies": {"af": "gnomAD_exomes_AF_afr", "ac": "gnomAD_exomes_AC_afr", "an": "gnomAD_exomes_AN_afr"}},
+    {"name": "gnomADe:amr", "frequencies": {"af": "gnomAD_exomes_AF_amr", "ac": "gnomAD_exomes_AC_amr", "an": "gnomAD_exomes_AN_amr"}},
+    {"name": "gnomADe:asj", "frequencies": {"af": "gnomAD_exomes_AF_asj", "ac": "gnomAD_exomes_AC_asj", "an": "gnomAD_exomes_AN_asj"}},
+    {"name": "gnomADe:eas", "frequencies": {"af": "gnomAD_exomes_AF_eas", "ac": "gnomAD_exomes_AC_eas", "an": "gnomAD_exomes_AN_eas"}},
+    {"name": "gnomADe:fin", "frequencies": {"af": "gnomAD_exomes_AF_fin", "ac": "gnomAD_exomes_AC_fin", "an": "gnomAD_exomes_AN_fin"}},
+    {"name": "gnomADe:nfe", "frequencies": {"af": "gnomAD_exomes_AF_nfe", "ac": "gnomAD_exomes_AC_nfe", "an": "gnomAD_exomes_AN_nfe"}},
+    {"name": "gnomADe:oth", "frequencies": {"af": "gnomAD_exomes_AF_oth", "ac": "gnomAD_exomes_AC_oth", "an": "gnomAD_exomes_AN_oth"}},
+    {"name": "gnomADe:sas", "frequencies": {"af": "gnomAD_exomes_AF_sas", "ac": "gnomAD_exomes_AC_sas", "an": "gnomAD_exomes_AN_sas"}}
+   ],
+    "gnomAD_genomes": [
+    {"name": "gnomADg:ALL", "frequencies": {"af": "gnomAD_genomes_AF", "ac": "gnomAD_genomes_AC", "an": "gnomAD_genomes_AN"}},
+    {"name": "gnomADg:afr", "frequencies": {"af": "gnomAD_genomes_AF_afr", "ac": "gnomAD_genomes_AC_afr", "an": "gnomAD_genomes_AN_afr"}},
+    {"name": "gnomADg:ami", "frequencies": {"af": "gnomAD_genomes_AF_ami", "ac": "gnomAD_genomes_AC_ami", "an": "gnomAD_genomes_AN_ami"}},
+    {"name": "gnomADg:amr", "frequencies": {"af": "gnomAD_genomes_AF_amr", "ac": "gnomAD_genomes_AC_amr", "an": "gnomAD_genomes_AN_amr"}},
+    {"name": "gnomADg:asj", "frequencies": {"af": "gnomAD_genomes_AF_asj", "ac": "gnomAD_genomes_AC_asj", "an": "gnomAD_genomes_AN_asj"}},
+    {"name": "gnomADg:eas", "frequencies": {"af": "gnomAD_genomes_AF_eas", "ac": "gnomAD_genomes_AC_eas", "an": "gnomAD_genomes_AN_eas"}},
+    {"name": "gnomADg:fin", "frequencies": {"af": "gnomAD_genomes_AF_fin", "ac": "gnomAD_genomes_AC_fin", "an": "gnomAD_genomes_AN_fin"}},
+    {"name": "gnomADg:mid", "frequencies": {"af": "gnomAD_genomes_AF_mid", "ac": "gnomAD_genomes_AC_mid", "an": "gnomAD_genomes_AN_mid"}},
+    {"name": "gnomADg:nfe", "frequencies": {"af": "gnomAD_genomes_AF_nfe", "ac": "gnomAD_genomes_AC_nfe", "an": "gnomAD_genomes_AN_nfe"}},
+    {"name": "gnomADg:oth", "frequencies": {"af": "gnomAD_genomes_AF_oth", "ac": "gnomAD_genomes_AC_oth", "an": "gnomAD_genomes_AN_oth"}},
+    {"name": "gnomADg:sas", "frequencies": {"af": "gnomAD_genomes_AF_sas", "ac": "gnomAD_genomes_AC_sas", "an": "gnomAD_genomes_AN_sas"}}
+    ]
+}

common/file_model/variant.py

@@ -27,6 +27,7 @@ def __init__(self, record: Any, header: Any) -> None:
         self.info = record.INFO
         self.type = "Variant"
         self.vep_version = re.search("v\d+", self.header.get_lines("VEP")[0].value).group()
+        self.population_map = {}
 
     def get_alternative_names(self) -> List:
         return []
@@ -196,7 +197,7 @@ def get_most_severe_consequence(self) -> Mapping:
             csq_record_list = csq_record.split("|")
             for cons in csq_record_list[consequence_index].split("&"):
                 rank = consequence_rank[cons]
-                consequence_map[rank] = cons
+                consequence_map[int(rank)] = cons
         return{
                     "result": consequence_map[min(consequence_map.keys())]  ,
                     "analysis_method": {
@@ -240,34 +241,121 @@ def get_info_key_index(self, key: str, info_id: str ="CSQ") -> int:
             for index, value in enumerate(csq_list):
                 if value == key:
                     return index   
+
+    def traverse_population_info(self) -> Mapping:
+        directory = os.path.dirname(__file__)
+        with open(os.path.join(directory,'populations.json')) as pop_file:
+            pop_mapping = json.load(pop_file)
+        population_frequency_map = {}
+        for csq_record in self.info["CSQ"]:
+            csq_record_list = csq_record.split("|")
+            allele_index = self.get_info_key_index("Allele") 
+            if csq_record_list[allele_index] is not None:
+                if csq_record_list[allele_index] not in population_frequency_map.keys():
+                    population_frequency_map[csq_record_list[allele_index]] = {}
+                for pop_key, pop in pop_mapping.items():
+                    for sub_pop in pop:
+                        if sub_pop["name"] in population_frequency_map[csq_record_list[allele_index]]:
+                            continue
+                        allele_count = allele_number = allele_frequency = None
+                        for freq_key, freq_val in sub_pop["frequencies"].items():
+                            col_index = self.get_info_key_index(freq_val)
+                            if col_index and csq_record_list[col_index] is not None:
+                                if freq_key == "af":
+                                    allele_frequency = csq_record_list[col_index] or None
+                                elif freq_key == "an":
+                                    allele_number = csq_record_list[col_index] or None
+                                elif freq_key == "ac":
+                                    allele_count = csq_record_list[col_index] or None
+                                else:
+                                    raise Exception('Frequency metric is not recognised')
+                                population_frequency = {
+                                                    "population_name": sub_pop["name"],
+                                                    "allele_frequency": allele_frequency,
+                                                    "allele_count": allele_count,
+                                                    "allele_number": allele_number,
+                                                    "is_minor_allele": False,
+                                                    "is_hpmaf": False
+                                                }
+                                if allele_frequency:
+                                    population_frequency_map[csq_record_list[allele_index]][sub_pop["name"]] = population_frequency
+        return population_frequency_map
 
-    def set_frequency_flags(self, allele_list: List):
+    def set_frequency_flags(self):
         """
-        Calculates minor allele frequency by iterating through each allele 
-        Assumption: Considers that population is only gnomAD (genomes) for now
-        Sets the maf as hpmaf as gnomAD is the only population at the moment
+        Calculates MAF (minor allele frequency) and  HPMAF by iterating through each allele 
         """
-        maf_frequency = -1
-        maf_index = -1
-        highest_frequency = -1
-        highest_frequency_index = -1
-        highest_maf_frequency = -1
-        highest_maf_frequency_index = -1
-        maf_map = {}
-        for allele_index, allele in enumerate(allele_list):
-            if(len(allele["population_frequencies"]) > 0):
-                pop = allele["population_frequencies"][0]
-                pop_allele_frequency = float(pop["allele_frequency"])
-                if ( pop_allele_frequency > maf_frequency and pop_allele_frequency < highest_frequency ):
-                    maf_frequency = pop_allele_frequency
-                    maf_index = allele_index
-                elif ( pop_allele_frequency > highest_frequency ):
-                    maf_frequency = highest_frequency
-                    maf_index = highest_frequency_index
-                    highest_frequency = pop_allele_frequency
-                    highest_frequency_index = allele_index
+        allele_list = self.get_alleles()
+        directory = os.path.dirname(__file__)
+        with open(os.path.join(directory,'populations.json')) as pop_file:
+            pop_mapping = json.load(pop_file)
+        pop_names = []
+        for pop in pop_mapping.values():
+            pop_names.extend([sub_pop["name"] for sub_pop in pop])
+        hpmaf = []
+        pop_frequency_map = self.traverse_population_info()
+
+        for pop_name in pop_names:
+            by_population = []
+            for allele in allele_list:
+                if allele.minimise_allele(allele.alt) in pop_frequency_map:
+                    pop_freqs = pop_frequency_map[allele.minimise_allele(allele.alt)].values()
+                # Calculate reference allele from parsed frequency info of all alleles
+                if allele.get_allele_type()["accession_id"] == "biological_region" and len(by_population)>0 :
+                     allele_frequency_ref = 1 - sum(list(zip(*by_population))[0])
+                     if allele_frequency_ref <= 1 and allele_frequency_ref >= 0:
+                        population_frequency_ref = {
+                                                "population_name": pop_name,
+                                                "allele_frequency": allele_frequency_ref ,
+                                                "allele_count": None,
+                                                "allele_number": None,
+                                                "is_minor_allele": False,
+                                                "is_hpmaf": False
+                                            }
+                        minimised_allele = allele.minimise_allele(allele.alt)
+                        if minimised_allele not in pop_frequency_map:
+                            pop_frequency_map[minimised_allele] = {}
+                        pop_frequency_map[minimised_allele][pop_name] = population_frequency_ref
+                        by_population.append([allele_frequency_ref,minimised_allele,pop_name])
+
+                else:       
+                    for pop_freq in pop_freqs:
+                        if pop_name == pop_freq["population_name"] and pop_freq["allele_frequency"]:
+                            minimised_allele = allele.minimise_allele(allele.alt)
+                            by_population.append([float(pop_freq["allele_frequency"]),minimised_allele, pop_name])
+
+
+
+            by_population_sorted = sorted(by_population, key=lambda item: item[0])
+            if len(by_population_sorted) >= 2:
+                highest_frequency = by_population_sorted[-1][0]
+                maf_frequency = None
+                # When more than one allele has same maf and is not 
+                # ref allele, we mark it as is_minor_allele
+                for pop in reversed(by_population_sorted[:-1]):
+                    if pop[0] == highest_frequency:
+                        continue
+                    elif pop[0] < highest_frequency and not maf_frequency:
+                        maf_frequency, maf_allele, maf_population = pop
+                        pop_frequency_map[maf_allele][maf_population]["is_minor_allele"] = True
+                        hpmaf.append([maf_frequency,maf_allele,maf_population])
+                    elif maf_frequency and pop[0] == maf_frequency and maf_allele != allele.ref:
+                        pop_frequency_map[maf_allele][maf_population]["is_minor_allele"] = True
+                        hpmaf.append([maf_frequency,maf_allele,maf_population])
+                    elif maf_frequency and pop[0] < maf_frequency:
+                        break
+        if len(hpmaf) > 0:
+            hpmaf_sorted = sorted(hpmaf, key=lambda item: item[0])
+            hpmaf_frequency, hpmaf_allele, hpmaf_population = hpmaf_sorted[-1]
+            pop_frequency_map[hpmaf_allele][hpmaf_population]["is_hpmaf"] = True
+            # When more than one allele has same maf, we mark it as is_hpmaf
+            for hpmaf_pop in reversed(hpmaf_sorted[:-1]):
+                if hpmaf_pop[0] == hpmaf_frequency:
+                    hpmaf_frequency, hpmaf_allele, hpmaf_population = hpmaf_pop
+                    pop_frequency_map[hpmaf_allele][hpmaf_population]["is_hpmaf"] = True
+                elif hpmaf_pop[0] < hpmaf_frequency:
+                    break
+        return pop_frequency_map
+
 
-        if maf_frequency>=0:
-            allele_list[maf_index]["population_frequencies"][0]["is_minor_allele"]  = True
-            allele_list[maf_index]["population_frequencies"][0]["is_hpmaf"]  = True  
 

common/file_model/variant_allele.py

@@ -15,6 +15,7 @@ def __init__(self, allele_index: str, alt: str, variant:dict) -> None:
         self.type = "VariantAllele"
         self.allele_sequence = alt
         self.reference_sequence = variant.ref
+        self.population_map = []
         self.info_map = self.traverse_csq_info()
 
     def get_allele_type(self):
@@ -41,7 +42,12 @@ def get_prediction_results(self):
         min_alt = self.minimise_allele(self.alt)
         return self.info_map[min_alt]["prediction_results"] if min_alt in self.info_map else []
 
-
+    def get_population_allele_frequencies(self):
+        min_alt = self.minimise_allele(self.alt)
+        population_map = self.variant.set_frequency_flags()
+        return population_map[min_alt].values() if min_alt in population_map else []
+
+
     def traverse_csq_info(self) -> Mapping:
         """
         This function is to traverse the CSQ record and extract columns
@@ -70,7 +76,47 @@ def traverse_csq_info(self) -> Mapping:
             current_prediction_results = info_map[csq_record_list[prediction_index_map["allele"]]]["prediction_results"] 
             info_map[csq_record_list[prediction_index_map["allele"]]]["prediction_results"] += self.create_allele_prediction_results(current_prediction_results, csq_record_list, prediction_index_map)
         return info_map
+
+    # def traverse_population_info(self) -> Mapping:
+    #     directory = os.path.dirname(__file__)
+    #     with open(os.path.join(directory,'populations.json')) as pop_file:
+    #         pop_mapping = json.load(pop_file)
+    #     population_frequency_map = {}
+    #     for csq_record in self.variant.info["CSQ"]:
+    #         csq_record_list = csq_record.split("|")
+    #         allele_index = self.variant.get_info_key_index("Allele") 
+    #         if csq_record_list[allele_index] is not None:
+    #             if csq_record_list[allele_index] not in population_frequency_map.keys():
+    #                 population_frequency_map[csq_record_list[allele_index]] = {}
+    #             for pop_key, pop in pop_mapping.items():
+    #                 for sub_pop in pop:
+    #                     if sub_pop["name"] in population_frequency_map[csq_record_list[allele_index]]:
+    #                         continue
+    #                     allele_count = allele_number = allele_frequency = None
+    #                     for freq_key, freq_val in sub_pop["frequencies"].items():
+    #                         col_index = self.variant.get_info_key_index(freq_val)
+    #                     if col_index is not None and csq_record_list[col_index] is not None:
+    #                         if freq_key == "af":
+    #                             allele_frequency = csq_record_list[col_index] 
+    #                         elif freq_key == "an":
+    #                             allele_number = csq_record_list[col_index] or None
+    #                         elif freq_key == "ac":
+    #                             allele_count = csq_record_list[col_index] or None
+    #                         else:
+    #                             raise Exception('Frequency metric is not recognised')
+    #                         population_frequency = {
+    #                                             "population": sub_pop["name"],
+    #                                             "allele_frequency": allele_frequency or -1,
+    #                                             "allele_count": allele_count,
+    #                                             "allele_number": allele_number,
+    #                                             "is_minor_allele": False,
+    #                                             "is_hpmaf": False
+    #                                         }
+
+    #                         population_frequency_map[csq_record_list[allele_index]][sub_pop["name"]] = population_frequency
+    #     return population_frequency_map
 
+
     def create_allele_prediction_results(self, current_prediction_results: Mapping, csq_record: List, prediction_index_map: dict) -> list:
         prediction_results = []
         if "cadd_phred" in prediction_index_map.keys():
@@ -219,30 +265,4 @@ def minimise_allele(self, alt: str):
         elif len(alt) < len(self.variant.ref):
             minimised_allele = "-"
         return minimised_allele
-
-    def format_frequency(self, raw_frequency_list: List) -> Mapping:
-        freq_map = {}
-        for freq in raw_frequency_list:
-            key = freq.split(":")[0]
-            freq_list = freq.split(":")[1].split(",")
-            freq_map[key] = freq_list
-        return freq_map
-
-    def get_population_allele_frequencies(self) -> List:
-        frequency_map = {}
-        if "FREQ" in self.variant.info:
-            frequency_map = self.format_frequency(",".join(map(str,self.variant.info["FREQ"])).split("|"))
-        population_allele_frequencies = []
-        for key, pop_list in frequency_map.items():
-            ## Adding only GnomAD population
-            if key == "GnomAD":
-                if pop_list[self.allele_index] not in ["None", "."]:
-                    population_allele_frequencies.append({
-                        "population": key,
-                        "allele_frequency": pop_list[self.allele_index],
-                        "is_minor_allele": False,
-                        "is_hpmaf": False
-                    })
-        return population_allele_frequencies
-
-
+

common/schemas/population.graphql

@@ -0,0 +1,14 @@
+type Population{
+"""
+  Population
+"""
+    name: String! 
+    size: Int!
+    description: String!
+    type: String!
+    is_global: Boolean!
+    is_from_genotypes: Boolean!
+    display_group_name: String!
+    super_population: Population
+    sub_populations: [Population!]!
+}

common/schemas/population_allele_frequency.graphql

@@ -2,8 +2,10 @@ type PopulationAlleleFrequency{
 """
   Population Allele Frequency
 """
-    population: String
-    allele_frequency: Float
-    is_minor_allele: Boolean
-    is_hpmaf: Boolean
-}
+    population_name: String!
+    allele_frequency: Float!
+    allele_count: Int
+    allele_number: Int
+    is_minor_allele: Boolean!
+    is_hpmaf: Boolean!
+}

common/schemas/query.graphql

@@ -1,6 +1,7 @@
 type Query {
   version: Version
   variant(by_id: IdInput): Variant
+  populations(genome_id: String!): [Population]
 }
 
 input IdInput {

examples/population/query.graphql

@@ -1,5 +1,5 @@
 query pop_example {
-  population(genome_id: "a7335667-93e7-11ec-a39d-005056b38ce3")
+  populations(genome_id: "a7335667-93e7-11ec-a39d-005056b38ce3")
   {
 
     name