Posterior Amorphous Corneal Dystrophy Is Associated with a Deletion of Small Leucine-rich Proteoglycans on Chromosome 12

Posterior amorphous corneal dystrophy (PACD) is a rare, autosomal dominant disorder affecting the cornea and iris. After next-generation sequencing of the family in which linkage analysis identified a chromosomal locus for PACD on 12q21.33 failed to yield a pathogenic mutation, array-based copy number analysis and qPCR detected a deletion on 12q21.33 containing four genes encoding small leucine-rich proteoglycans (SLRPs): KERA, LUM, DCN, and EPYC. Two other families with PACD also demonstrated deletion of these SLRPs, which together with murine models of KERA, LUM, and DCN deficiency provide convincing evidence that PACD is caused by haploinsufficiency of these SLRPs. Copy number analysis of 750K SNP and 1.9 non-polymorphic probes present on the Affymetrix CytoScan HD array. Samples were separated by affection status. Eight unaffected and 5 affected samples from across 3 families were analyzed. Analysis was performed using the Affymetrix Chromosome Analysis Suite (ChAS) v.2.0 software.