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Clinical outcome of eight BIGH3-linked corneal dystrophies.
OBJECTIVE: To determine whether the mutational pattern of BIGH3-linked corneal dystrophies (CDs) can accurately predict the clinical course of the disease and be helpful in planning adequate surgical treatment.
DESIGN: Retrospective noncomparative case series.
PARTICIPANTS: Chart review of 73 patients (110 eyes) with recently confirmed BIGH3 mutations who underwent a penetrating keratoplasty (PK) from 1978 through 1999. Diagnoses included Thiel-Benhke CD (TBCD/R555Q) (13 eyes), classic granular CD (CGCD/R555W) (28 eyes), superficial variant of granular dystrophy (SVGD/R124 l) (27 eyes), lattice CD type I (LCDI/R124C) (20 eyes), Avellino CD (ACD/R124H) (2 eyes), H626R-lattice dystrophy (LCD/H626R) (6 eyes), and two novel dystrophies: a French variant of granular dystrophy (FVGD/R124 l+DT125-DE126) (9 eyes) and a French lattice CD type IIIA (LCDIIIA/A546T) (5 eyes).
METHODS: The mutation of the BIGH3 gene was characterized for all patients. Clinical data were reviewed for each patient, and included age at first PK and elapsed time before significant recurrence (as defined by a severe decrease in best-corrected visual acuity related to recurrent deposits in the graft).
MAIN OUTCOME MEASURES: Mean age at first PK and delay before a significant recurrence.
RESULTS: Mutational pattern was highly correlated with the clinical course of each dystrophy. According to the genetic mutation, two groups with different prognosis were identified. Group 1 was defined by the presence of the FVGD/R124 l+DT125-DE126 and SVGD/R124 l mutations and was characterized by the early need for treatment and early recurrence of deposits. Group 2 was molecularly defined by the presence of any of the following mutations: LCDI/R124C, CGCD/R555W, LCDIIIA/A546T, TBCD/R555Q, and LCD/H626R. In group 2, mean age at first treatment was older, and delay before a significant recurrence was longer as compared with group 1 (P = 0.0001).
CONCLUSIONS: These results demonstrate that there is a direct correlation between the molecular defect and the clinical course of BIGH3-linked CDs. They also indicate that molecular characterization of the genetic defect will help predict and design adequate surgical treatment for patients with ambiguous clinical diagnosis.
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