Mice with recessive cataract, CXSD, show the first clinical symptoms of cataract at five weeks, with complete penetrance. We previously localized the cataract-causing<i> lens rupture 2</i> gene <i>(lr2)</i> to mouse chromosome 14. In the process of positional cloning of the <i>lr2</i> gene, we determined the genomic organization of the critical region, defined by <i>D14Mit262</i> and <i>D14Mit86</i>, and compared it to recently published map information. In addition, mutational analysis using reverse transcription polymerase chain reaction (RT-PCR) followed by direct sequencing as well as quantitative realtime PCR (RQ-PCR) was performed to investigate <i>Adam28</i> and <i>Adamdec1</i> as <i>lr2</i> candidate genes in this study. There was no mutation cosegregating with the phenotype of CXSD mice, which excluded these genes as the <i>lr2</i> gene. Identification of more transcripts from this region and their mutation analyses are required to isolate the <i>lr2</i> gene.