A novel TGFBI phenotype with amyloid deposits and Arg124Leu mutation.

ABSTRACT

AIM: To report a unique transforming-growth-factor-ß-induced (TGFBI) gene phenotype with Arg124Leu mutation in an Indian family. METHODS: A family with 5 affected members presented to our hospital and were clinically diagnosed as suffering from Bowman layer dystrophy after examination. Peripheral blood samples were collected in EDTA from all for genomic DNA isolation. Keratoplasty was performed in 2 patients followed by histopathological evaluation of the cornea. DNA was subjected to PCR amplification of TGFBI and tumor-associated calcium signal transducer 2 (TACSTD2) genes followed by direct sequencing of all coding exons to identify the causative mutations. RESULTS: Slitlamp examination of the cornea revealed superficial reticular opacities with diffuse anterior stromal haze suggestive of Bowman layer dystrophy but histopathological examination revealed the presence of both hyaline and amyloid deposits in the cornea. TGFBI sequencing revealed a heterozygous mutation, Arg124Leu (c.418 G→T) in all the affected members while TACSTD2 did not show any changes. CONCLUSIONS: Molecular analysis established the diagnosis of a novel TGFBI variant with Arg124Leu mutation. The presence of lattice- like lines clinically and histopathological demonstration of both amyloid and hyaline deposits with the occurrence of Arg124Leu mutation in all the affected family members are an unusual phenomenon and are here described for the first time.