As reported in this review, the major gene disorder related to microtia phenotype is found in TCOF1 (32.82%; 28 cases), followed by GSC exon 2 (6.82%), FANCB (4.55%), SIX2 (3.41%), HSPA9 (3.41%) and CDT1 (3.41%) (Fig. 5) with each characteristic (Table 7). The gene discussed is SIX2; the disease is microtia.