The TGFBI A546D mutation causes an atypical type of latticecorneal dystrophy

[摘要] Purpose: To report the clinical, molecular, and histopathologicalfeatures of a distinct transforming growth factor-β-induced(TGFBI) gene-linked amyloidotic corneal dystrophy exhibiting anunusual lattice pattern.Methods: A complete ophthalmologic examination was performed in 10individuals of a Mexican family in which autosomal dominant transmissionof the disease was observed. DNA was obtained from peripheral bloodleukocytes of each participating subject. Genetic analyses includedTGFBI polymerase chain reaction (PCR) amplification and automatednucleotidic sequencing of exons 4, 11, 12, 13, and 14 from genomic DNA.Histological analysis of corneal tissue from an affected individual whounderwent a penetrating keratoplasty was also performed.Results: The corneal phenotype in this pedigree was characterized bymultiple bilateral round opacities in the central part of the corneacombined with a conspicuous central and peripheral lattice pattern.TGFBI analysis revealed a heterozygous point mutation at exon 12(1637 C>A) in all affected individuals, predicting an A546D missensechange.Conclusions: The lattice phenotype resulting from the TGFBI A546Dmutation in this family is distinct from that observed in a previouslydescribed pedigree carrying the A546D mutation and exhibiting aphenotype designated "polymorphic corneal amyloidosis". We propose thisparticular disorder to be classified as an atypical type of latticestromal corneal dystrophy.

[学科分类] 生物化学/生物物理