TCS had a lower percentage of total T cells CD3+ (62.3% (53.8–68.2) vs 73.3% (65.4–81.5) p = 0.017) and CD4+ T cells (34.4% (27.9–41.5) vs 42.8% (34.5–52.8) p = 0.024) cells in total lymphocytes compared to controls. This evidence concerns the gene CD4 and Treacher-Collins syndrome.