TCOF1 and Treacher Collins syndrome 1: The main cause of TCS1 is the variants in TCOF1 locus, which is located on chromosome 5q32‐q33.1, containing 28 exons and encoding 4465 base pairs (Zhang et al., 2013); It also encodes a low‐complexity, and serine/alanine‐rich protein called the Treacle protein, which is composed of 1488 amino acids with a molecular weight of about 152 KD, and has three domains, namely the N‐terminal and C‐terminal, and a central repetitive domain (Pan et al., 2021).