Novel Mutations in the M1S1 Gene Associated With Gelatinous Drop-like Corneal Dystrophy in Japan

Abstract

Purpose:: To report novel mutations of the M1S1 gene in two cases of gelatinous drop-like dystrophy (GDLD).

Methods:: A 22-year-old Japanese man and a 75-year-old Japanese woman diagnosed as GDLD on the basis of the slit-lamp examination were studied. After prior informed consent was obtained, genomic DNA was extracted from their peripheral blood. The coding region of the M1S1 gene was amplified by PCR and subjected to direct sequencing.

Results:: Direct sequencing revealed that both patients have mutations in the M1S1 gene. The 22-year-old man was found to be homozygous for the 20 base pair insertion at nucleotide position 839 (20-BP INS, NT839), which will cause frame-shift mutation. The 75-year-old woman was found to have homozygous point mutation at nucleotide position 675, which will result in amino acid transition from tyrosine to stop codon at amino acid position 225 (Y225X). These results were further validated by PCR (to detect length-difference in amplified fragment) or 1-base primer extension assay, respectively.

Conclusions:: We have found novel M1S1 mutations in two cases of Japanese GDLD. Functional analysis is now on-going to further investigate the relationship between these mutations and GDLD.

Keywords: cornea: clinical science • cornea: epithelium