PURPOSE: Meesmann corneal dystrophy (MECD) is an autosomal dominant disorder affecting the corneal epithelium. It is caused by heterozygous mutations in KRT3 or KRT12 gene. Actually, 14 mutations have been reported, 1 in KRT3 and 13 in KRT12. These genes were screened in several patients suffering from MECD. METHODS: Patients from 2 families were screened for mutation in KRT3 and KRT12. Exons were PCR-amplified and directly sequenced. The new mutation was checked by DHPLC in 51 control individuals of Swiss origin. RESULTS/CONCLUSIONS: In one family, the M129T heterozygous mutation was observed in KRT12. In the second family, we identified a novel I426S heterozygous mutation in exon 6 of KRT12.