Exclusion of TACSTD2 in an Iranian GDLD pedigree

Abstract

Purpose: To perform a mutation screen of TACSTD2 in an Iranian Gelatinous Drop-like Corneal Dystrophy (GDLD) pedigree.

Methods: In addition to the coding region of TACSTD2, for the first time the promoter, the entire 5'-noncoding region, and the entire 3'-untranslated region of the gene were sequenced from an affected member of the pedigree. Phenotypic features of affected individuals were assessed.

Results: The proband carried six sequence variations in TACSTD2. One of the variations was homozygous and caused a synonymous codon change. The remaining five were heterozygous variations in the 3'-untranslated region. None of the variations were assessed to be associated with GDLD. Fibroblastic scars were evident in in corneal histology sections of two affected members of the pedigree.

Conclusions: It is concluded that GDLD in the pedigree is probably not caused by mutations in TACSTD2, supporting evidence for the existence of at least one other locus for GDLD. Phenotypic features of the Iranian patients, including the existence of fibroblastic scars in the corneas, were similar to those of a previously reported GDLD patient without TACSTD2 mutations. This suggests the disease in these individuals may be due to mutations in the same gene.