Hallermann-Streiff syndrome (HSS), also known as oculomandibulofacial syndrome or Hallermann-Streiff-Francois syndrome, is a rare disorder that manifests characteristic skull and facial bone malformations, distinctive facial features, sparse hair, dental deformities, ocular abnormalities, facial skin atrophy, and short stature.

This syndrome is found equally in males and females, with clinical presentations varying in severity. Hypotrichosis is present in 80% of patients. Craniofacial features usually include brachycephaly, prominent forehead, micrognathia, and beaked nose. Ocular features include congenital cataracts, microphthalmia, and enophthalmos. Dental features may include presence of teeth at birth and/or improperly aligned, malformed, or absent teeth. While most children with HSS have normal intelligence, about 15% of patients may have an intellectual disability. In rare instances, neurological abnormalities have been reported.

Underdeveloped jaw, downward displacement of the tongue, and nasal anatomy may lead to upper airway obstruction of varying severity. Tracheomalacia may be present in some cases and cause further swallowing and breathing difficulties. In severe cases, heart failure may occur as a complication of respiratory insufficiency. Ocular manifestations may cause varying degrees of visual impairments or blindness.

The precise genetic cause is currently unknown. Usually, HSS occurs sporadically in patients with no apparent family history of the disease. It appears to be inherited in an autosomal recessive manner in a minority of cases.