Nicolaides-Baraitser syndrome (NCBRS) has a similar phenotype to CSS and can be kept as a differential diagnosis. CSS was first reported and discovered by Evelyn Siris and Grange S. Coffin in the year 1970 [1-2]. ARID1B-related disorder (ARID1B-RD) results from pathogenic heterozygous variants in the ARID1B gene, which can manifest as classic CSS and intellectual disability, with or without nonspecific dysmorphic features. This evidence concerns the gene ARID1B and intellectual disability - sparse hair - brachydactyly.