Yunis-Varon syndrome (YVS) is a severe autosomal recessive disorder characterized by skeletal defects, including cleidocranial dysplasia and digital anomalies, and severe neurologic involvement with neuronal loss. Enlarged cytoplasmic vacuoles are found in neurons, muscle, and cartilage. The disorder is usually lethal in infancy (summary by Campeau et al., 2013).

Short stature, auditory canal atresia, mandibular hypoplasia, and skeletal abnormalities (SAMS) is an autosomal recessive multiple congenital anomaly syndrome with features of a first and second branchial arch syndrome. Craniofacial abnormalities can lead to conductive hearing loss, respiratory insufficiency, and feeding difficulties. Additional features include rhizomelic skeletal anomalies as well as abnormalities of the shoulder and pelvic joints. Affected individuals may also have some features of a neurocristopathy or abnormal mesoderm development, such as urogenital anomalies, that are distinct from other branchial arch syndromes (summary by Parry et al., 2013).