CHM and choroideremia: From our experimental analyses of three unrelated Chinese families, we expand the spectrum of choroideremia-related mutations by adding two novel mutations (c.227_232delinsTGTCATTTCA, p.Q76Lfs*7; c.710dupA, p.Y237_S238delinsX) and a previously reported mutation (c.1584_1587del TGTT, p.V529Hfs*7) to the existing disease-causing variants in CHM gene.