The usefulness of buccal swabs for mutation screening in patients with suspected corneal dystrophies

Abstract

Purpose: To make ophthalmologists aware of the usefulness of buccal swabs for the collection of cells from which DNA may be extracted to be used in genetic screening of patients with known or suspected inherited ocular disorders, such as corneal dystrophies.

Design: Illustrative interventional case report.

Methods: Buccal epithelial swabs were collected from a 3-year-old boy with a presumed corneal dystrophy and his unaffected parents. Swabs were mailed to a laboratory where transforming growth factor-beta-induced gene (TGFBI) mutation screening was performed.

Main outcome measures: Results of sequencing TGFBI exons 4 and 12.

Results: Transforming growth factor-beta-induced gene mutation screening in a child with bilateral anterior corneal stromal opacification revealed the following changes in exon 12: 1667T>C (Phe540Phe), 1684C>A (Ala546Asp), and 1699C>A (Pro551Gln). The child's father demonstrated the 1667T>C nucleotide substitution, but neither parent demonstrated the 1684T>C or the 1699C>A changes.

Conclusions: Buccal swabs provide the ophthalmologist with a simple, inexpensive means of collecting and transporting cells from which DNA may be extracted to be used to either confirm or refute diagnoses solely on the basis of clinical features. In this case, the diagnosis of an atypical variant of lattice corneal dystrophy was made on the basis of the identification of previously reported mutations in TGFBI.