Congenital hereditary endothelial dystrophy caused by SLC4A11 mutations progresses to Harboyan syndrome.

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Homozygous mutations in SLC 4 A 11 cause 2 rare recessive conditions : congenital hereditary endothelial dystrophy (CHED ), affecting the cornea alone , and Harboyan syndrome consisting of corneal dystrophy and sensorineural hearing loss . In addition , adult-onset Fuchs endothelial corneal dystrophy (FECD ) is associated with dominant mutations in SLC 4 A 11 . In this report , we investigate whether patients with CHED go on to develop hearing loss and whether their parents , who are carriers of an SLC 4 A 11 mutation , show signs of having FECD .Patients with CHED were screened for mutations in the SLC 4 A 11 gene and underwent audiometric testing . The patients and their parents underwent a clinical examination and specular microscopy .Molecular analyses confirmed SLC 4 A 11 mutations in 4 affected individuals from 3 families . All the patients were found to have varying degrees of sensorineural hearing loss at a higher frequency range . Guttate lesions were seen in 2 of the 4 parents who were available for examination .Our observations suggest that CHED caused by homozygous SLC 4 A 11 mutations progresses to Harboyan syndrome , but the severity of this may vary considerably . Patients with CHED should therefore be monitored for progressive hearing loss . We could not determine conclusively whether the parents of the patients with CHED were at increased risk of developing late-onset FECD .