Fryns syndrome is a rare, autosomal recessive multiple congenital anomaly syndrome characterized by diaphragmatic defects, characteristic facial features, and distal limb hypoplasia.
Here's a breakdown of the key features:
-
Diaphragmatic Defects: These are the hallmark of Fryns syndrome and can include:
- Diaphragmatic hernia (a hole in the diaphragm, allowing abdominal organs to move into the chest cavity)
- Eventration (abnormal elevation of the diaphragm)
- Hypoplasia (underdevelopment of the diaphragm)
- Agenesis (complete absence of the diaphragm)
-
Characteristic Facial Features: These often include:
- Coarse facial features
- Widely spaced eyes (hypertelorism)
- Wide and depressed nasal bridge with a broad nasal tip
- Long philtrum (the vertical groove between the nose and upper lip)
- Low-set and anomalous ears
- Tented vermilion of the upper lip (the red part of the lip appears pointed or tent-shaped)
-
Distal Limb Hypoplasia: This refers to underdevelopment of the extremities, particularly the fingers and toes. This can include short fingers (brachydactyly), absent or hypoplastic nails, or other abnormalities of the hands and feet.
Other Associated Features: Besides the core characteristics, individuals with Fryns syndrome may also present with other anomalies, including:
- Cardiac defects: Congenital heart abnormalities
- Kidney abnormalities: Renal agenesis or cystic kidneys
- Brain abnormalities: Malformations of the brain
- Polyhydramnios: Excessive amniotic fluid during pregnancy.
Genetic Basis: Fryns syndrome is inherited in an autosomal recessive manner. This means that both parents must be carriers of the mutated gene for a child to be affected. The specific gene(s) responsible for Fryns syndrome are not fully understood.
Diagnosis: Diagnosis is often made prenatally via ultrasound, observing the diaphragmatic hernia and other characteristic features. Postnatal diagnosis is based on clinical examination and the presence of the key features.
Prognosis: The prognosis for Fryns syndrome is generally poor. Many affected infants are stillborn or die shortly after birth due to complications related to the diaphragmatic hernia and other severe anomalies.
