Posters

A novel mutation of granular corneal dystrophy type 2 (Avellino corneal dystrophy) in Thai families

Poster Details

First Author: T.Mirasena THAILAND

Co Author(s):    P. Chantaren   V. Puangsricharern   W. Tulvatana   C. Ittiwut   R. Ittiwut   K. Suphapeetiporn     

Abstract Details

Purpose:

To describe the clinical manifestations and genotypic mutation in the unrelated families with clinical diagnosis of granular corneal dystrophy type 2 (GCD2), also known as Avellino corneal dystrophy (ACD)

Setting:

King Chulalongkorn Memorial Hospital and Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand

Methods:

Three patients and family members with different clinical appearances of GCD2 were examined by slit-lamp and confocal microscopy. Genomic DNA was extracted from peripheral blood leukocytes of each family members. The whole-exome sequencing was used to identify the mutation in the TGFBI gene. The corneal specimen obtained from the proband of each family was examined histopathologically.

Results:

The proband of the first family had granular lesion and atypical lattice lesion which was confirm by confocal microscopy, but a genetic study found heterozygous missense c.1663C>T (p.Arg555Trp, R555W) which was known to associated with GCD1. The proband of the second and third family had typical clinical finding and histopathology of GCD2. A novel heterozygous missense c.1574C>A (p.Ala525Glu, R525E) was found in the second family, and a heterozygous missense c.1694T>A (p.Leu565His, p.L565H), which is atypical variant, was found in the third family.

Conclusions:

We described three families with clinical finding of GCD2, however, 3 different genotypes were identified. The first mutation is typically found in GCD1, the second mutation is novel, and the third mutation is rare variant. The variation of clinical manifestation in GCD2 could lead to misdiagnose or underdiagnose, so genetic test is essential in inconclusive cases or atypical cases. However, genotypic variation should be awared.

Financial Disclosure:

None