More de novo heterozygous mutations were later reported in patients with similar features, including SOX11-containing 2p25 deletions, a nonsense variant, and additional HMG-domain missense variants [14], but deeper phenotyping and analysis of DNA-methylation profiles proved that this condition is distinct from Coffin–Siris syndrome (CSS) [15]. Here, SOX11 is linked to Coffin-Siris syndrome.