MedGen

X-linked retinitis pigmentosa and sinorespiratory infections with or without deafness (RPSRDF) is characterized by typical features of RP, including night blindness, constricted visual fields, progressive reduction in visual acuity, bone-spicule pigmentation, and extinguished responses on electroretinography. Affected individuals also experience severe recurrent sinorespiratory infections, and some develop progressive hearing loss. Carrier females may show an attenuated ocular and/or respiratory phenotype (Zito et al., 2003; Moore et al., 2006). [from OMIM]

X-linked retinitis pigmentosa (XLRP) is a severe form of inherited retinal degeneration that primarily affects the rod photoreceptors (Demirci et al., 2002). It typically causes an early-onset night blindness and loss of peripheral vision, often causing patients to become legally blind by the age of 30 to 40 years. In RP3, affected males have a severe phenotype, and carrier females show a wide spectrum of clinical features ranging from completely asymptomatic to severe RP (Jin et al., 2007). Mutation in the RPGR gene is believed to account for approximately 70% of XLRP (Vervoort et al., 2000). For a discussion of genetic heterogeneity of retinitis pigmentosa, see 268000. [from OMIM]

X-linked cone-rod dystrophy is a rare, progressive visual disorder primarily affecting cone photoreceptors (Demirci et al., 2002). Affected individuals, essentially all of whom are males, present with decreased visual acuity, myopia, photophobia, abnormal color vision, full peripheral visual fields, decreased photopic electroretinographic responses, and granularity of the macular retinal pigment epithelium. The degree of rod photoreceptor involvement is variable, with increasing degeneration. Although penetrance appears to be nearly 100%, there is variable expressivity with respect to age at onset, severity of symptoms, and findings (Hong et al., 1994). Genetic Heterogeneity of X-linked Cone-Rod Dystrophy Additional forms of X-linked cone-rod dystrophy include CORDX2 (300085), mapped to chromosome Xq27, and CORDX3 (300476), caused by mutation in the CACNA1F gene (300110) on chromosome Xp11.23. For a discussion of autosomal forms of cone-rod dystrophy, see CORD2 (120970). [from OMIM]