More than 200 distinct mutations have been reported in TCOF1, accounting for about 70–93% of TCS individuals, which are inherited via an autosomal dominant pattern, while POLR1D and POLR1C mutations have been found in about 11–23% of the remaining patients, which are inherited via autosomal dominant and autosomal recessive patterns, respectively [3, 5–7]. Here, POLR1D is linked to Treacher-Collins syndrome.