Purpose: To investigate the choroideremia (CHM) gene in two families with CHM and to characterize the related clinical features.
Methods: Two families underwent complete ophthalmic examinations and three males were diagnosed with CHM. Genomic DNA was extracted from the leukocytes of peripheral blood collected from the two families and from 100 unrelated control subjects from the same population. Exons 1-15 of CHM were amplified by PCR and directly sequenced. Ophthalmic examinations included best-corrected visual acuity, slit-lamp examination, fundus examination, visual field, optical coherence tomography, electroretinogram, and Pentacam.
Results: The affected men were hemizygous and had night blindness, chorioretinal atrophy spreading from the posterior pole to the mid-periphery, and bareness of the sclera. A novel c.1488delGinsATAAC mutation was detected in CHM in family 1. Another mutation c.1703 C>G (S558X) within exon 14 of CHM was identified in family 2, which caused the serine 558 codon (TCA) to be changed to a stop codon (TGA).
Conclusions: This study identified a novel mutation in CHM associated with CHM and its related clinical features. Our findings expand the genotypic spectrum of CHM mutations associated with CHM and confirm the role of Rab escort protein-1 in the pathogenesis of CHM.