Rapid detection of M1S1 mutations by the protein truncation test

PURPOSE. To determine a method of rapid detection of M1S1 gene mutations in patients with gelatinous droplike corneal dystrophy. METHODS. Forty-one patients from 35 families with gelatinous drop-like corn eal dystrophy were studied. The entire coding region of the M1S1 gene was s creened using the protein truncation test (PTT), with a polymerase chain re action fragment amplified from genomic DNA serving as a template of in vitr o translation. RESULTS. Homozygous or compound heterozygous mutations were detected in all patients by a single reaction of the PTT. This result matched those obtain ed using the polymerase chain reaction-restriction fragment length polymorp hism and direct sequence analyses. The Q118X mutation was present in 63 of the 70 alleles, accounting for 90% of the disease-associated chromosomes in Japanese patients. CONCLUSIONS. The PTT is useful for detecting mutations in the M1S1 gene. Th is technique showed that the Q118X mutation is a founder mutation in Japane se patients with gelatinous droplike corneal dystrophy, and it reflects the linkage disequilibrium reported previously.