Khan et al. (2004) described an Arab family of first cousin parents with six siblings, five of whom were affected with autosomal recessive cornea plana.  All affected children had high hyperopia, small flat corneas, arcus senilis, short axial lengths, and asymmetric anterior chamber depth.  The parents and the unaffected brother had normal ophthalmic features.  Mutation analysis revealed a novel homozygous point mutation in the KERA gene in all affected members, the parents were carriers, and the unaffected brother had no KERA mutation.  In a second case, Khan et al. (2005) described 12 individuals from a Saudi nuclear family with autosomal recessive cornea plana.  Only one family member had a history of progressive visual difficulty over the last several years, and this was due to an increasing astigmatic refractive error.  A novel homozygous mutation was detected in five siblings with clinically evident cornea plana and the sister with clinical findings of pellucid marginal degeneration and cornea plana.  All other family members were heterozygous for the mutation and clinically unaffected.