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.
Q87.0 – Congenital malformation syndromes predominantly affecting facial appearance
7903009 – Hallermann-Streiff Syndrome
- Progeria (Hutchinson-Gilford syndrome) – Patients have premature atherosclerosis, nail dystrophy, arthritis, acromicria, and normal ocular findings.
- Pseudoprogeria – Patients have normal appearance at birth, psychomotor delay, and severe spastic quadriplegia.
- Mandibulofacial dysostosis (Treacher-Collins syndrome) – Patients have ear anomalies and lower eyelid colobomas.
- Neonatal progeroid syndrome (Wiedemann-Rautenstrauch syndrome) – Patients have unusually thin arms and legs with abnormally large hands and feet, subcutaneous lipoatrophy, and the syndrome is autosomal recessive.