Hallermann-Streiff syndrome is a rare, congenital condition characterized mainly by abnormalities of the skull and facial bones; characteristic facial features; sparse hair; eye abnormalities; dental defects; degenerative skin changes; and proportionate short stature. Intellectual disability is present in some individuals. Almost all reported cases of the condition appear to have occurred randomly for unknown reasons (sporadically) and are thought to have resulted from a new mutation in the affected individual. Treatment is symptomatic and supportive.
The signs and symptoms of Hallermann-Streiff syndrome vary in range and severity among affected individuals. The main features of the condition include abnormalities of the skull and facial bones with distinctive facial characteristics (craniofacial abnormalities); ocular (eye) abnormalities; dental abnormalities; and/or short stature.
Craniofacial features may include a short, broad head (brachycephaly) with an unusually prominent forehead and/or sides of the skull (frontal bossing); a small, underdeveloped lower jaw (micrognathia); a narrow, highly arched roof of the mouth (palate); and a thin, pinched, tapering nose (beaked nose). Ocular abnormalities may include clouding of the lenses of the eyes at birth (congenital cataracts); unusually small eyes (microphthalmia); and/or other abnormalities.
Dental defects may include the presence of teeth at birth (natal teeth) and/or absence, malformation, or improper alignment of teeth. Hypotrichosis (sparse hair) is present in about 80 percent of affected individuals. Other features may include skin atrophy of the face, and/or hypoplasia (underdevelopment) of the clavicles and ribs. Intellectual disability is present in some cases (approximately 15 percent). In many cases, additional abnormalities are present.
The genetic cause of Hallerman-Streiff syndrome has not been identified. It reportedly typically occurs randomly for unknown reasons (sporadically), most likely due to a new spontaneous (de novo) mutation in the affected individual.
The majority of cases of Hallermann-Streiff syndrome appear to be sporadic (occurring in individuals with no history of the condition in the family). There have been reports of affected individuals having multiple, unaffected children. Although some have reported it appears to be inherited in an autosomal recessive manner in a small number of cases, others have argued that there is little evidence for this being a recessively inherited disorder. Therefore, the mode of inheritance of the condition remains unclear.
While we are not aware of clinical genetic testing for Hallermann-Streiff syndrome, GeneTests lists laboratories offering research genetic testing for this condition. To view information for the laboratories offering research genetic testing for Hallermann-Streiff syndrome click here. Research genetic tests may be used to find disease-causing genes, learn how genes work, or aid in the understanding of a genetic disorder. In many cases test results are not shared with the patient or physician. Talk to your health care provider or a genetics professional to learn more about research testing for this condition.
The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Treatment for Hallermann-Streiff syndrome depends on the specific signs and symptoms present in each affected individual. Early disease management for infants may include monitoring of breathing, consideration of tracheostomy, and various measures to improve feeding and ensure sufficient intake of nutrients. Although early surgical removal of cataracts may be recommended to help preserve vision, some studies have suggested that spontaneous cataract absorption may occur in up to 50% of untreated patients. Regular appointments with an ophthalmologist are strongly recommended to identify and treat other eye abnormalities, some of which may require surgical intervention.
With respect to dental anomalies, natal/neonatal teeth (teeth present at birth) may be incorrectly diagnosed as extra teeth and there may be a tendency to extract them. However, the loss of teeth may worsen glossoptosis (posteriorly location of the tongue) or cause other complications. It has thus been recommended to preserve prematurely erupting teeth to facilitate eating until the existence of successional permanent teeth can be confirmed. Ensuring good dental hygiene is also important.
Management of the condition may also include surgical reconstruction of certain craniofacial malformations (particularly the mandibular and nasal region) at the appropriate age. For some affected infants and children with heart defects, medical treatment and/or surgical intervention may be recommended