Purpose: The aim of this study was to examine the carbohydrate sulfotransferase 6 (CHST6) gene for mutations in a sibship with both macular corneal dystrophy (MCD) types I and II.
Design: Clinically relevant laboratory investigation.
Methods: The coding region of the CHST6 gene was examined for mutations.
Results: In one sibling, MCD type I was due to a homozygous C1110T (Arg140end) mutation in CHST6. Two MCD type II individuals exhibited three heterozygous nucleotide changes: C1110T, G1360A (Gly223Asp), and G1685T (Gln331His). Analysis of the upstream region was performed on one individual with MCD type II, and no upstream deletion or substitution was found.
Conclusions: These findings fit the haplotype analysis that we reported previously and indicate that the predicted protein that is encoded by CHST6 is more severely affected in the individual with MCD type I than in the siblings with MCD type II.