Aims: To report a Bangladeshi family displaying intrafamilial phenotypic heterogeneity of lattice corneal dystrophy type I (LCDI) and to identify the causative mutation.
Methods: Molecular genetic analysis was performed on DNA extracted from all members of the family. Exons of BIGH3 gene were amplified by polymerase chain reaction. Gene mutation and polymorphisms were identified by heteroduplex and sequence analyses. Segregation of the mutation in the family was confirmed by restriction digestion of amplified gene fragments.
Results: A heterozygous C --> T transition at the first nucleotide position of codon 124 of the BIGH3 gene was detected in the three affected members and not in the unaffected members of the family.
Conclusions: This is the first report of BIGH3 gene mutation in a Bangladeshi family with phenotypic heterogeneity. This study confirms that BIGH3 gene screening should be undertaken for proper classification of corneal dystrophy, especially in the absence of histopathological examination.