X-linked cone-rod dystrophy, type 1 explained

X-linked cone-rod dystrophy, type 1
Synonyms:	CORDX1, CORD1, Cone-rod dystrophy X-linked 1.^[1]
Onset:	Early infancy
Duration:	Lifelong
Risk:	-->
Prevention:	none
Management:	-->
Prognosis:	Medium
Frequency:	rare
Deaths:	-

X-linked cone-rod dystrophy, type 1 is a rare progressive genetic disorder of the vision which is characterized by progressive myopia, photophobia, abnormal color perception, lowered photopic electroretinigraphic response, and macular retinal pigment epithelium granularity. The severity of the symptoms is variable. Peripheral vision is unaffected in most of the cases.^[2] It is one of the three types of X-linked cone-rod dystrophy.^[3]

This condition is linked to mutations (c.2383G > T, p.E795X) in the RPGR gene, located in the Xp11.4 region of the X chromosome, and it is inherited in an X-linked dominant manner with full penetrance, because of this, it mostly affects males.^{[4] [5] [6]}

Prevalence is unknown, although usual cone-rod dystrophy has a prevalence of around 1-9 out of 40,000-100,000 live births.^{[7] [8]}

Notes and References

1. Web site: Cone-rod dystrophy X-linked 1 . Genetic and Rare Diseases (GARD) . National Institutes of Health, U.S. Department of Health & Human Services .
2. Web site: Entry - #304020 - CONE-ROD DYSTROPHY, X-LINKED, 1; CORDX1 . 2022-07-18 . Online Mendelian Inheritance in Man (OMIM) . en-us.
3. Web site: Cone-Rod Dystrophies, X-Linked . Hereditary Ocular Diseases . 2022-07-18 . University of Arizona .
4. Demirci FY, Rigatti BW, Wen G, Radak AL, Mah TS, Baic CL, Traboulsi EI, Alitalo T, Ramser J, Gorin MB . 6 . X-linked cone-rod dystrophy (locus COD1): identification of mutations in RPGR exon ORF15 . American Journal of Human Genetics . 70 . 4 . 1049–1053 . April 2002 . 11857109 . 379101 . 10.1086/339620 .
5. Wang Y, Liu S, Zhai Y, Liu Y, Wan X, Wang W, Wang F, Sun X . 6 . Identification of a novel RPGR mutation associated with X-linked cone-rod dystrophy in a Chinese family . BMC Ophthalmology . 21 . 1 . 401 . November 2021 . 34800980 . 8605601 . 10.1186/s12886-021-02166-0 . free .
6. Seymour AB, Dash-Modi A, O'Connell JR, Shaffer-Gordon M, Mah TS, Stefko ST, Nagaraja R, Brown J, Kimura AE, Ferrell RE, Gorin MB . 6 . Linkage analysis of X-linked cone-rod dystrophy: localization to Xp11.4 and definition of a locus distinct from RP2 and RP3 . American Journal of Human Genetics . 62 . 1 . 122–129 . January 1998 . 9443860 . 10.1086/301667 . 1376794 .
7. Web site: Orphanet: Cone rod dystrophy . 2022-07-18 . www.orpha.net . en.
8. Web site: Cone-rod dystrophy . MedlinePlus Genetics . National Library of Medicine, National Institutes of Health, U.S. Department of Health & Human Services . 2022-07-18 . en.