Borate transporter SLC4A11 mutations cause both Harboyan syndrome and non-syndromic corneal endothelial dystrophy

Abstract

Harboyan syndrome (CDPD) consists of congenital corneal endothelial dystrophy and progressive perceptive deafness and is transmitted as an autosomal recessive trait. CDPD and autosomal recessive, non-syndromic congenital hereditary endothelial corneal dystrophy (CHED2) both map at overlapping loci at 20p13, and mutations of SLC4A11 were recently reported in CHED2. We here report genotype studies in six families with CDPD and one family with either CHED or CDPD, from various ethnic backgrounds (in the seventh families hearing loss could not be assessed because of the proband’s young age). We found novel SLC4A11 mutations in all patients. Why some mutations cause hearing loss in addition to corneal dystrophy is presently unclear. Our findings extend the implication of the SLC4A11 borate transporter beyond corneal dystrophy to perceptive deafness.