The propositus, a 9-year-old boy, was born to healthy unrelated Caucasian parents aged 34 years (mother) and 40 years (father) (). He has one healthy sister and two healthy maternal half siblings. During pregnancy a small exomphalos was detected by ultrasound. He was delivered at term by normal vaginal delivery. Based on postnatal clinical examination and imaging studies, he was noted to have marked hypertelorism, bilateral coloboma, absence of the corpus callosum, malrotation of the gut, bilateral inguinal hernias, but not congenital diaphragmatic hernia. He had his omphalocele reduced on day 1, his inguinal hernias repaired at 1 year of age, and definitive surgery for his malrotation at 18 months of age.
Proband at 8 years of age with characteristic craniofacial features of DBS/FOAR syndrome. Note hypertelorism, downslanting palpebral fissures, and iris colobomas.
At 4 months of age his head circumference was 44.5 cm (95th centile), height 60.6 cm (90th centile), and weight 5.78 kg (90th centile). MRI scan of the brain confirmed the corpus callosum agenesis, and also revealed a frontal encephalocele with a widened anterior fossa, and a Chiari 1 malformation with cerebellar tonsils extending to C1.
His ocular manifestations include bilateral iris and chorioretinal colobomas, high myopia, right inferior cataract, and left posterior lenticonus, diagnosed at 3 months of age. His myopia is associated with enlarged globes (axial length measuring 30 mm at age 7 years), bilateral posterior staphylomata, and he received prophylactic 360 degree laser retinopexy to prevent retinal detachment. His glasses prescription is OD −15.00 D, OS−19.25/−2.00 axis 92°, although he usually wears contact lenses, and achieves corrected visual acuities of OD 20/200, OS 20/100. Although he had normal electrodiagnostic results at the age of 7 years, over the past 2 years the patient reported visual deterioration, especially at night. Repeat electroretinography age 9 years revealed generalized retinal dysfunction involving both the rod and cone systems mainly at the photoreceptor/retinal pigment epithelial interface. Ocular measurements at 6 years of age were 45, 70, and 110 mm for inner canthal, interpupillary, and outer canthal distances, respectively.
Cochlear implants were inserted at age 4 due to severe bilateral deafness, revised at age 6, and again at age 8. He attends a mainstream school and has specialist support for his visual and hearing deficits. He demonstrates some developmental delay, attending a class two years behind his peers. However, he is making good progress in this class, and much of his developmental delay is thought to be explained by his bisensory impairment, and gaps in his schooling due to frequent hospitalizations.
Chromosomal analysis revealed a normal male karyotype (46,XY) (data not shown).