Moleculargenetic Findings and Therapeutical Options in a Well Examined German Family With Macular Corneal Dystrophy

Abstract

Abstract: : Purpose: Mutations in the carbohydrate sulfotransferase 6 gene (CHST6) were identified to cause the autosomal recessive macular corneal dystrophy type I (MCD). We report on the moleculargenetic findings and early intervention with phototherapeutic keratectomy for treatment of macular corneal dystrophy in a well examined German family. Methods: Genomic DNA was extracted from the leucocytes in the peripherial blood of two affected sisters, their nonaffected parents and their nonaffected brother . The coding region of CHST6 was examined for mutations by polymerase chain reaction and direkt sequencing. Both sisters underwent phototherapeutic keratectomy in both eyes because of progredient corneal opacities and decreased visual acuity. Results: Both sisters were homozygous for a novel missense mutation A–>T in nucleotid 181 of the CHST6 gene wich results in a homozygous amino acid translation Met1Leu in the start codon of the CHST6 gene in both sisters. All of the nonaffected examined family members had a heterozygous missense mutation A–>T in nucleotid 181 of the CHST6 gene. Uncorrected visual acuity of both sisters improved from a mean of 0.25 to a mean of 0.64. After a follow up of 9 months there has been no anterior recurrence, no haze and no complications. Conclusions: Missense mutation in the CHST6 start codon leeds to a relative mild form of MCD type I wich can successfully treated with phototherapeutic keratectomy. Early intervention is relatively safe and preferable to observation or penetrating keratoplasty.

Keywords: cornea: clinical science • genetics • laser