In the case of different nuclear antigens, including SS-B, SS-A 52 kDa, Scl 70, Jo-1, snRNP/Sm, Sm, and SS-A 60 kDa, the overall rate of IgG seropositivity was 0% (0/27) in the CC group and 12.5% (3/24) in the LC group. This evidence concerns the gene SSB and laryngotracheoesophageal cleft.