Contributor: Gordon K. Klintworth
Ehlers-Danlos syndrome type VI (EDSVI, EDS6, Ehlers-Danlos syndrome, kyphoscoliotic type; Ehlers-Danlos syndrome, oculoscoliotic type; fragilitas oculi with joint hyperextensibility, brittle cornea syndrome, Ehlers-Danlos syndrome VI phenotype with macrocephaly, OMIM # 225400 and OMIM # 229200). This variant of Ehlers-Danlos syndrome has been mapped to human chromosome 1 (1p36.3-p36.2) and sometimes results from a defect in the PLOD gene.The syndrome has an autosomal recessive mode of inheritance. This type may develop a dissecting aortic aneurysm [aneurysm - dissecting]. Ophthalmologic manifestations are common and include retinal detachment, glaucoma, microcornea, brownish or blue sclerae, a large cloudy thin bulging cornea, tortuous retinal arteries and myopia. The bulging cornea resemble buphthalmos, but without an elevated intraocular pressure. The corneal fragility presisposes to repeated rupture. In common with osteogenesis imperfecta affected individuals may have dental anomalies and a predisposition to fractures of bones, hernia and long slender hyperextensible fingers. The cornea changes need to be differentiated from keratoglobus (thinning of cornea is generalized) and keratoconus (corneal thinning is mainly central). Ehlers-Danlos syndrome type VI is divided into two types based on whether lysyl hydroxylase is deficient on not: Ehlers-Danlos syndrome type VIA, Ehlers-Danlos syndrome type VIB. Most cases with the brittle cornea syndrome fall into the Ehlers-Danlos syndrome type VIB variant.