Hallermann–Streiff syndrome

Overview

Hallermann–Streiff syndrome is a rare congenital disorder characterized by distinctive craniofacial features, dental abnormalities, eye problems, and growth deficiency. First described by Hallermann in 1948 and later expanded by Streiff, the condition affects multiple systems, particularly skeletal, ocular, and dermatological structures. Individuals with the syndrome often have a characteristic "bird-like" facial appearance, with a small, beaked nose, underdeveloped jaw, and sparse hair. Despite physical differences, intellectual development is typically normal in many cases.

Causes

The exact cause of Hallermann–Streiff syndrome remains unknown, although most cases appear to be sporadic, occurring without a family history. It is believed to result from a de novo genetic mutation affecting craniofacial development, though no specific gene has been conclusively identified. There is currently no evidence of a clear hereditary pattern, although extremely rare familial cases have been reported.

Symptoms

Hallermann–Streiff syndrome presents with a range of distinctive signs and symptoms, including:

• Craniofacial anomalies: Micrognathia (small jaw), prominent forehead, thin, beaked nose, and hypoplastic (underdeveloped) facial bones.

• Ocular defects: Congenital cataracts, microphthalmia (abnormally small eyes), nystagmus, and strabismus.

• Dental abnormalities: Malformed or missing teeth, delayed tooth eruption, and high-arched palate.

• Hypotrichosis: Sparse scalp hair, eyebrows, and eyelashes.

• Skin issues: Thinning or atrophy of the skin, particularly over the scalp and face.

• Short stature and growth delay: Present from infancy and continuing into adulthood.

• Airway and feeding difficulties: Due to facial structure abnormalities and micrognathia.

Diagnosis

Diagnosis is primarily clinical, based on the characteristic physical features and confirmed through imaging and specialist evaluations. Diagnostic approaches include:

• Clinical examination: Identification of typical facial features, dental anomalies, and growth patterns.

• Ophthalmologic evaluation: To assess for cataracts and other eye abnormalities.

• Radiographic imaging: Skull X-rays or CT scans may reveal craniofacial bone abnormalities.

• Genetic testing: Although no single gene has been identified, whole-exome sequencing may be performed to rule out overlapping syndromes.

Treatment

There is no cure for Hallermann–Streiff syndrome, and treatment focuses on managing individual symptoms and improving quality of life. A multidisciplinary team approach is essential. Treatment options include:

• Surgical correction: For cataracts, dental issues, or jaw abnormalities.

• Ophthalmologic care: Early intervention for visual impairment, including cataract surgery and corrective lenses.

• Dental care: Prosthodontics and orthodontics to manage malformed or missing teeth.

• Airway support: In cases of breathing difficulty, tracheostomy or CPAP may be required.

• Speech and feeding therapy: To support feeding issues and speech development.

• Growth monitoring: Regular assessment to track physical development and provide supportive interventions if needed.

Prognosis

The prognosis for individuals with Hallermann–Streiff syndrome varies depending on the severity of associated complications. While intellectual development is usually normal, physical challenges may require ongoing medical and surgical management. Early diagnosis, supportive care, and timely interventions can significantly improve the individual's quality of life. Most affected individuals live into adulthood, although respiratory issues in infancy may pose early-life risks.