Cerebro-costo-mandibular syndrome is a very rare genetic disorder in which mutations in the small nuclear ribonucleoprotein polypeptides B and B1 (SNRPB) genes cause various skeletal anomalies of the thorax and spine. The diagnosis is made based on clinical criteria and the prognosis depends on the severity of defects and associated complications, most important being frequent upper respiratory tract infections.
Cerebro-Costo-Mandibular syndrome (CCMS) is presumably inherited through an autosomal dominant mode (although sporadic cases have been identified). This means that symptoms are almost universally seen in the setting of a positive family history. They can commence soon after birth, but the majority of cases are diagnosed during infancy or childhood [1] [2]. The cardinal features of CCMS are:
The diagnosis of CCMS may not be easy, as less than 100 cases have been described in the literature [2] [5]. Nevertheless, a detailed patient history regarding the onset of symptoms and a thorough physical examination can provide sufficient data to raise clinical suspicion. The presence of micrognathia and respiratory difficulties necessitate the use of imaging studies, such as plain radiography, computed tomography (CT) or magnetic resonance imaging (MRI). Chest X-rays will reveal a narrow or bell-shaped thorax and bilateral multiple posterior rib gaps, while mandibular hypoplasia can be confirmed using either X-rays or CT [1] [2] [6]. Radiography may be employed if hypoplasia of other skeletal structures (extremities or the clavicles) is suspected as well, whereas cardiac and renal structures should be evaluated by CT or MRI. Additionally, endocranial imaging (preferably MRI) is advocated, particularly if signs of mental retardation exist [2]. Some reports suggest that a prenatal diagnosis of CCMS can be made using fetal ultrasonography and identifying thoracic, facial abnormalities and increased nuchal translucency [6].