fryns syndrome

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Fryns syndrome (FS) is a rare congenital disorder which can have significant phenotypic variability but is primarily characterized by cranio-facial anomalies, diarphagmatic defects and distal limb anomalies.

Epidemiology

Incidence is estimated at 1:15,000 live births.

Clinical presentation

The clinical spectrum is wide and reported clinical features include

cranio-facial features
- dysmorphic facial features (coarse facies)
- microphthalmia
- hypertelorism
- facial hair growth or facial hirsuitism
- corneal clouding
- long philtrum
- broad and flat nasal bridge
- macrostomia
- cleft lip and/or palate
- microretrognathia or micrognathia
- low-set ears
- intracranial anomalies
  - fetal ventriculomegaly or fetal hydrocephalus
  - agenesis of the corpus callosum
  - neuronal or cerebellar heterotopia(s)
diaphragmatic or thoracic defects
- congenital diaphragmatic herniation
  - can be a prominent feature and is the commonest autosomal recessive syndrome associated with a congenital diaphragmatic herniation
- congenital diaphragmatic eventration
- pulmonary hypoplasia: which in turn can give rise to a small thorax
limb anomalies
- brachytelaphalangia
  - distal limb hypoplasia
  - distal digital hypoplasia

Pathology

Genetics

It is thought to carry an autosomal recessive inheritance.

Associations

These can also be sometimes be considered as part of the clinical spectrum listed above

Radiographic features

Antenatal ultrasound

Some of the above clinical features may be evident on antenatal ultrasound. First trimester ultrasound may show a cystic hygroma as an early (but non specific) feature.

Treatment and prognosis

The prognosis is generally poor with a majority of cases being stillborn or not surviving beyond the early neonatal period. A lot of the mortality can be due to development of pulmonary hypoplasia. In those who survive severe developmental delay and intellectual disability are common.