Microdeletions of chromosome 7p21, including TWIST1, associated with significant microcephaly, facial dysmorphism, and short stature

Abstract: Saethre–Chotzen syndrome due to TWIST1 mutations is characterized by coronal synostosis, facial dysmorphism and additional variable anomalies. Small deletions comprising the whole TWIST1 account for a small proportion of patients with Saethre–Chotzen syndrome. Here we describe 3 patients with facial dysmorphism, marked microcephaly, short stature (2/3 patients), and overlapping 7p21 microdeletions. Molecular karyotyping identified small deletions of chromosome 7p21 including TWIST1 with a size of 526 kb, 9.2 Mb, and 11.7 Mb, respectively. The clinical manifestations of these patients do not resemble the typical phenotype of Saethre–Chotzen syndrome. In the two patients with larger microdeletions, severe mental retardation and significant short stature are present. Facial dysmorphism of patient 3 includes also signs of blepharophimosis–ptosis–epicanthus inversus syndrome. [Copyright &y& Elsevier]