It is a genetic disorder characterized by the association of diaphragmatic hernia, exomphalos, absent corpus callosum, hypertelorism, eye anomalies, and sensorineural deafness. The classic distinguishing features between faciooculoacousticorenal (FOAR) and Donnai-Barrow Syndromes are the presence of proteinuria, the absence of diaphragmatic hernia and agenesis of the corpus callosum in the FOAR Syndrome.
Faciooculoacousticorenal Syndrome; FOAR Syndrome; DBS; Diaphragmatic Hernia, Exomphalos, Absent Corpus Callosum, Hypertelorism, Myopia, Sensorineural Deafness and Proteinuria Syndrome.
This medical condition was first described in 1993 by Donnai and Barrow.
Twenty cases have been reported since its first description. Some researchers believe that Donnai-Barrow Syndrome and Faciooculoacousticorenal (FOAR) Syndrome belong to the same entity. The classic distinguishing features between the two disorders are the presence of proteinuria, the absence of diaphragmatic hernia and agenesis of the corpus callosum in the FOAR Syndrome.
It is inherited as autosomal recessive trait. It is caused by homozygous or compound heterozygous mutation in the LRP2 gene on chromosome 2q31.
The precise mechanism resulting in the findings of this syndrome remains to be determined.
Pregnancy may be complicated by polyhydramnios, and prenatal diagnosis can be made by ultrasonography.
Patients are born with bilateral absence of the diaphragm (some die shortly after birth as a result of severe pulmonary hypoplasia). Congenital heart disease may coexist (double outlet right ventricle, ventricular septal defect, patent foramen ovale, persistent ductus arteriosus). Omphalocele (exomphalos), intestinal malrotation, absent corpus callosum, severe myopia (15-20 diopters), iris coloboma, retinal detachment, sensorineural deafness, and variable degree of developmental delay are characteristics of this syndrome. Other distinct features include facial dysmorphism with enlargement of both fontanels, hypertelorism with down-slanting palpebral fissures, broad nose, angulated ears, and mild micrognathia.
Precautions before anesthesia
Evaluate the degree of the newborn’s illness. Depending on the amount of abdominal contents in the chest and the severity of pulmonary hypoplasia, the neonate may require immediate tracheal intubation and controlled ventilation or even extracorporeal membrane oxygenation (ECMO). In the presence of severe pulmonary hypoplasia with pulmonary hypertension, an attempt at inhalation of nitric oxide to reduce pulmonary vascular resistance may be worthwhile, before ECMO is considered. ECMO is the ultimate bridging management for refractory cases; however, the prognosis is unfavorable for patients with severely hypoplastic lungs and pulmonary vasculature. The size of the omphalocele is usually moderate. Obtain a chest radiograph and echocardiography to rule out possible congenital cardiac lesions. Laboratory investigations should include serum electrolytes and glucose, hemoglobin, blood type, cross-match, and arterial blood gas analysis. Later in life, consider administration of an anxiolytic premedication for elective surgery if mental retardation is present.