Brittle cornea syndrome 2 (BCS2)

Brittle cornea syndrome 1 and 2

Brittle cornea syndrome 1 (BCS1; MIM 229200), and brittle cornea syndrome 2 (BCS2; MIM 614170), also known as Ehlers-Danlos syndrome, type VIB (EDS VIB) are autosomal recessive disorders caused by mutations in the zinc finger 469 gene (ZNF469) and PR domain-containing protein 5 (PRDM5) genes, respectively. Major features of BCS include spontaneous rupture of the cornea or rupture of the cornea following minor trauma, keratoglobus, keratoconus, blue sclera, joint hypermobility, scoliosis, hip dysplasia, hyperelasticity of the skin, dentinogenesis imperfecta and mixed conductive and sensorineural hearing loss. BCS is progressive and often leads to blindness. Some affected individuals have also been reported to have an increased proclivity to fractures. BCS shares many features with Ehlers-Danlos syndrome, kyphoscoliotic type (EDS VI; MIM 225400). However, individuals with EDS VI are biochemically characterized by deficient collagen lysyl hydroxylase activity while individuals with BCS have normal lysyl hydroxylase activity.