   KEY name_idx (variation_name),
 	KEY source_idx (source_id),
 	KEY study_idx (study_id),
-	KEY attrib_idx (class_attrib_id)
+	KEY attrib_idx (class_attrib_id),
+	KEY clinical_attrib_idx (clinical_significance_attrib_id)
 );
 
 

@column variation_set_id		             The structural variation feature can belong to a @link variation_set.
@column somatic                          Flags whether this structural variation is known to be somatic or not
@column breakpoint_order                 Defines the order of the breakpoints when several events/mutation occured for a structural variation (e.g. somatic mutations)

@see structural_variation
@see source
@see seq_region
@see attrib
@see variation_set

CREATE TABLE structural_variation (
  structural_variation_id int(10) unsigned NOT NULL AUTO_INCREMENT,
  variation_name varchar(255) DEFAULT NULL,
  alias varchar(255) DEFAULT NULL,
	source_id int(10) unsigned NOT NULL,
  study_id int(10) unsigned DEFAULT NULL,
	class_attrib_id int(10) unsigned NOT NULL DEFAULT 0,
	clinical_significance_attrib_id int(10) unsigned DEFAULT NULL,
  validation_status ENUM('validated','not validated','high quality'),
	is_evidence TINYINT(4) DEFAULT 0,
	somatic TINYINT(1) NOT NULL DEFAULT 0,
