Harboyan Syndrome Clinical CharacteristicsOcular Features: The combination of congenital endothelial dystrophy and progressive neural deafness is known as Harboyan syndrome. This disorder must be distinguished from another autosomal recessive disorder, congenital endothelial dystrophy 2 or CHED2 (217700), in which deafness does not occur. While the corneal disease in Harboyan is present at birth, the deafness often does not become obvious until the second and third decades of life although audiometry can detect some hearing loss in the first decade. The cornea is thickened and edematous resulting in various degrees of visual impairment, even to the level of counting fingers. Electrophysiologic studies have been normal. Systemic Features: No systemic abnormalities have been reported. GeneticsThis is an autosomal recessive disorder caused by a mutation in the SLC4A11 gene located on chromosome 20 (20p13-12). It is allelic to simple, congenital endothelial corneal dystrophy (CHED2) (217700). About half of reported cases occur sporadically and the rest have been reported in offspring of consanguineous matings. Less than 30 cases have been reported worldwide. Pedigree: Autosomal recessiveTreatmentTreatment Options: Corneal transplantation is the treatment of choice and can result in substantial visual improvement. ReferencesArticle Title: Congenital hereditary endothelial dystrophy with Desir J, Abramowicz M. Congenital hereditary endothelial dystrophy with progressive sensorineural deafness (Harboyan syndrome). Orphanet J Rare Dis. 2008 Oct 15;3:28. Review. PubMed ID: 18922146 Borate transporter SLC4A11 mutations cause both Harboyan syndrome and non-syndromic corneal endothelial dystrophy Desir J, Moya G, Reish O, Van Regemorter N, Deconinck H, David KL, Meire FM, Abramowicz MJ. Borate transporter SLC4A11 mutations cause both Harboyan syndrome and non-syndromic corneal endothelial dystrophy. J Med Genet. 2007 May;44(5):322-6. PubMed ID: 17220209 Congenital corneal dystrophy Harboyan G, Mamo J, Kaloustian V der, Karam F. Congenital corneal dystrophy. Progressive sensorineural deafness in a family. Arch Ophthalmol. 1971 Jan; 85(1):27-32. PubMed ID: 5312820 Read more about Harboyan Syndrome
Congenital hereditary endothelial dystrophy with Desir J, Abramowicz M. Congenital hereditary endothelial dystrophy with progressive sensorineural deafness (Harboyan syndrome). Orphanet J Rare Dis. 2008 Oct 15;3:28. Review. PubMed ID: 18922146
Borate transporter SLC4A11 mutations cause both Harboyan syndrome and non-syndromic corneal endothelial dystrophy Desir J, Moya G, Reish O, Van Regemorter N, Deconinck H, David KL, Meire FM, Abramowicz MJ. Borate transporter SLC4A11 mutations cause both Harboyan syndrome and non-syndromic corneal endothelial dystrophy. J Med Genet. 2007 May;44(5):322-6. PubMed ID: 17220209
Congenital corneal dystrophy Harboyan G, Mamo J, Kaloustian V der, Karam F. Congenital corneal dystrophy. Progressive sensorineural deafness in a family. Arch Ophthalmol. 1971 Jan; 85(1):27-32. PubMed ID: 5312820
