CLINICAL CHARACTERISTICS AND MOLECULAR GENETIC ANALYSIS OF A COHORT OF CHINESE PATIENTS WITH CHOROIDEREMIA.

PURPOSE

To describe the clinical and molecular genetic characteristics of a large cohort of Chinese patients with choroideremia (CHM).

METHODS

Forty-eight Chinese participants from 35 families with a clinical diagnosis of CHM who harbored sequence variants in the CHM gene were enrolled. Comprehensive clinical evaluations and molecular genetic analysis of the CHM gene were performed.

RESULTS

The median age of the 48 patients was 31.5 years (range, 5-78 years). There were 30 different sequence variants detected in 35 families; of which, 13 sequence variants were novel. The mean (±SD) best-corrected visual acuity best in logarithm of the minimum angle of resolution equivalents was 0.71 (±0.87) (range, 0.00-2.80) or approximately 20/100 in Snellen visual acuity. A significant correlation was revealed between best-corrected visual acuity best and age (P < 0.001). The trend in the change in the best-corrected visual acuity over age showed that relatively good vision remained until 20 years old. The patterns of fundus photography and fundus autofluorescence finding demonstrated that residual retinal pigment epithelium areas significantly declined in patients at the age of 20 years or older. The results of visual field and full-field electroretinography showed that these measures might be of limited value for evaluating the condition of the late stage of CHM in Chinese patients.

CONCLUSION

This study described for the first time the clinical and molecular genetic characteristics of a large cohort of Chinese patients with CHM. The findings from best-corrected visual acuity best and visual field showed that the impairment of visual function in CHM might be more severe in Chinese patients than in western patients.