Variants in several genes encoding SOX transcription factors cause a variety of developmental disorders named SOXopathies. SOX4 variants were previously reported in four individuals with a neurodevelopmental syndrome. As with many other rare conditions, an international effort helped identify many additional patients and hence better define the clinical and genetic spectrum of the disease. The SOX4-related disorder features developmental delay, various neurologic abnormalities, mild dysmorphisms, and inconstant anomalies in multiple somatic systems. The previously classification (CSS10) within the Coffin-Siris syndrome family is arguable because coarse facies, hypertrichosis and hypoplastic terminal phalanges are usually absent in individuals with SOX4 pathogenic variants. (By Drs. Veronique Lefebvre and Rebecca Ahrens-Nicklas, https://jmg.bmj.com/content/early/2022/02/28/jmedgenet-2021-108375 )