Abstract
Objective: Macular corneal dystrophy (MCD) is an autosomal recessive inheritance disorder which manifests bilateral corneal opacity. It has been reported that keratan sulfate side chains on keratan sulfate proteoglycans are not sulfated.
Furthermore, a previous study showed decreased sulfotransferase activity in the cornea, which leads to the accumulation of low sulfated keratan sulfate in a MCD cornea. Recently, the corneal N-acetylglucosamine-6-sulfotransferase gene (C-G1cNAc6ST, CHST6) has been identified as the causative gene for MCD. To assess the genetic characteristics of a Japanese family with MCD, we looked for a mutation in the CHST6 gene in patients with MCD.
Patients: A patient with MCD and her family were included in this study.
Methods: DNA was isolated from peripheral blood cells of the patient and selected relatives. The CHST6 gene was amplified and directly sequenced.
Results: Direct sequencing of the CHST6 gene revealed that the patient has a single base-pair substitution, resulting in an amino acid substitution at 211 arginine to tryptophane (Arg211Trp).
Conclusion: The patient had no detectable keratan sulfate in the serum and accumulation in the cornea was positively stained with the 1/20-5D4 antibody as in a previous study. Arg211Trp may cause a new variant form of type I MCD.
