Screening of additional families with PACD will likely reveal interstitial deletions of the PACD locus in each, and depending on the extent of the deleted region, may suggest that LUM deficiency alone is sufficient to cause PACD or that it is the additive effect of the deletion of several SLRPs that is involved in the pathogenesis of PACD. This evidence concerns the gene LUM and posterior amorphous corneal dystrophy.