摘要

Choroideremia is an X-linked recessive chorioretinal degenerative disease that is characterized by progressive centripetal loss of the photoreceptor, retinal pigment epithelium (RPE), and choriocapillaris layers. The CHM gene [choroideremia (Rab escort protein 1)] has been identified as the pathogenic gene in choroideremia. The aim of the present study was to describe the clinical and genetic characteristics of a family with choroideremia family. In the present study, a family with choroideremia presenting with serious chorioretinal atrophy and pigment proliferation, shallow anterior chambers, angle closure and high intraocular pressure (IOP) were recruited. The affected family members underwent a complete ophthalmologic examination. DNA samples obtained from the proband II:1 and the patient II:2 were used for targeted exome sequencing of the CHM gene. PCR amplification and Sanger sequencing were used to validate the variations exhibited in family members and controls. A novel frameshift mutation c.280delA (p.Thr94LeufsTer32), in CHM was identified in the male proband, the normal carrier I:2 and the phenotyped carrier II:2, which was absent in the normal individual II:3 as well as in 200 normal controls. Comparing the amino acid sequences of CHM between multiple species through Clustal Omega indicated conserved amino acids in these mutant sites. Additionally, an X-chromosome inactivation (XCI) assay was performed in the female carriers in the family, in which DNA of the abnormal carrier II:2 and normal carrier I:2 showed a random XCI pattern. To conclude, the present findings strongly indicate that the c.280delA mutation is a disease-causing mutation in our choroideremia pedigree with acute angle-closure glaucoma.

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