Background: To report the clinical, histopathological and immunohistochemical findings of two novel mutations within the TGFBI gene.
Methods: The genotype of 41 affected members of 16 families and 9 sporadic cases was investigated by direct sequencing of the TGFBI gene. Clinical, histological and immunohistochemical characteristics of corneal opacification were reported and compared with the coding region changes in the TGFBI gene.
Results: A novel mutation Leu509Pro was detected in one family with a geographic pattern-like clinical phenotype. Histopathologically we found amyloid together with nonamyloid deposits and immunohistochemical staining of Keratoepithelin (KE) KE2 and KE15 antibodies. In two families and one sporadic case the novel mutation Gly623Arg with a late onset, map-like corneal dystrophy was identified. Here amyloid and immunohistochemical staining of only KE2 antibodies occured. Further we report on 5 already known mutations: Arg124Cys Arg555Trp Arg124His His626Arg, Ala546Asp in 13 families and 5 sporadic cases of German origin. We did not identify the underlying gene defect within the TBFBI gene in any of the 4 probands with Thiel-Behnke corneal dystrophy.
Conclusions: The two novel mutations within the TGFBI gene add another two phenotypes with atypical immunohistochemical and histopathological features to those so far reported.