def get_genetic_map_HapMapII_GRCh37(self):
        if self._genetic_map_HapMapII_GRCh37 is None:
            self._genetic_map_HapMapII_GRCh37 = self._load_genetic_map(
                self._get_path_genetic_map_HapMapII_GRCh37()
            )
        return self._genetic_map_HapMapII_GRCh37