What are the other Names for this Condition? (Also known as/Synonyms)

• Francois Dyscephalic Syndrome
• Hallermann Streiff Francois Syndrome
• HSS (Hallermann-Streiff Syndrome)

What is Hallermann-Streiff Syndrome? (Definition/Background Information)

• Hallermann-Streiff Syndrome (HSS) 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

(Source: Hallermann-Streiff Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Hallermann-Streiff Syndrome? (Age and Sex Distribution)

• Hallermann-Streiff Syndrome is a rare disorder that manifests at birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Hallermann-Streiff Syndrome? (Predisposing Factors)

• Currently, no risk factors have been clearly identified for Hallermann-Streiff Syndrome

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Hallermann-Streiff Syndrome? (Etiology)

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

(Source: Hallermann-Streiff Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

What are the Signs and Symptoms of Hallermann-Streiff Syndrome?

The signs and symptoms of Hallermann-Streiff Syndrome may include:

• Abnormality of the hand
• Abnormality of the nasopharynx
• Blue sclerae
• Cataract
• Choreoathetosis
• Decreased number of sternal ossification centers
• Dental malocclusion
• Dolichocephaly
• Downslanted palpebral fissures
• Dry skin
• Everted lower lip vermilion
• Fine hair
• Hyperactivity
• Hyperlordosis
• Joint hypermobility
• Hypotrichosis of the scalp
• Metaphyseal widening
• Obstructive sleep apnea
• Parietal bossing
• Pectus excavatum
• Platybasia
• Recurrent respiratory infections
• Recurrent pneumonia
• Scoliosis
• Slender long bone
• Sparse hair
• Spina bifida
• Telangiectasia
• Thin calvarium
• Thin ribs
• Thin vermilion border
• Wormian bones

Very frequently present symptoms in 80-99% of the cases:

• Alopecia
• Brachycephaly
• Congenital cataract
• Convex nasal ridge
• Dermal atrophy
• Frontal bossing
• Hypotrichosis
• Microphthalmia
• Proportionate short stature
• Reduced bone mineral density
• Rib exostoses
• Short ribs
• Sparse body hair

Frequently present symptoms in 30-79% of the cases:

• Glossoptosis
• Abnormality of hair texture
• Abnormality of the fontanelles or cranial sutures
• High, narrow palate
• Increased number of teeth
• Malar flattening
• Micrognathia
• Narrow mouth
• Natal tooth
• Recurrent fractures
• Sparse and thin eyebrow
• Sparse eyelashes
• Telecanthus
• Underdeveloped nasal alae
• Visual impairment

Occasionally present symptoms in 5-29% of the cases:

• Abdominal situs inversus
• Abnormality of cardiovascular system morphology
• Cerebellar hypoplasia
• Choanal atresia
• Clinodactyly of the 5th finger
• Congestive heart failure
• Cryptorchidism
• Glaucoma
• Hypothyroidism
• Intellectual disability
• Microcephaly
• Myopia
• Nystagmus
• Respiratory insufficiency
• Short foot
• Small hand
• Tracheomalacia
• Uveitis

(Source: Hallermann-Streiff Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Hallermann-Streiff Syndrome Diagnosed?

Hallermann-Streiff Syndrome is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Hallermann-Streiff Syndrome?

The complications of Hallermann-Streiff Syndrome may include:

• Loss of sight
• Heart abnormalities
• Physical deformities

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Hallermann-Streiff Syndrome Treated?

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

(Source: Hallermann-Streiff Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How can Hallermann-Streiff Syndrome be Prevented?

• Currently, Hallermann-Streiff Syndrome may not be preventable, since it is a genetic disorder
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Hallermann-Streiff Syndrome? (Outcomes/Resolutions)

• The prognosis of Hallermann-Streiff Syndrome is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Hallermann-Streiff Syndrome:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/