MMP1 and laryngotracheoesophageal cleft: A meta-analysis among diverse populations showed that MMP1-1607 2G/2G showed higher risk of LC than MMP1-1607 1G carriers (MMP1-1607 1G/1G and MMP1-1607 1G/2G), besides, MMP1-1607 2G carriers (MMP1-1607 2G/2G and MMP1-1607 1G/2G) showed significant higher risk of LC than MMP1-1607 1G/1G (34) (Table 4).