TTC3 is highly expressed in mouse at 14.5 days and in human heart tissue (Zaidi et al., 2013); a previous study showed that the gene correlates with cardiac defects in Down syndrome patients (Ripoll et al., 2012), and TTC3 is a novel candidate gene based on array comparative genomic hybridization (aCGH) for 316 nonsyndromic CHD children (Sanchez-Castro et al., 2016). This evidence concerns the gene TTC3 and Down syndrome.