[Clinical and genetic features of choroideremia].
BACKGROUND
Choroideremia is an X-linked hereditary eye disease that causes progressive degeneration of the choroid and retina and frequently leads to legal blindness in later life. Recent molecular genetic studies have revealed mutations involving the Rab escort protein (REP-1) gene localized at Xq 21.


METHODS
The clinical picture and rate of progression may vary among affected individuals in different families and within the same family. Usually, hemizygous males develop night blindness in their teenage years, followed by progressive peripheral visual field constriction and visual disability in late age. Heterozygous female carriers are mostly asymptomatic, but their fundi show characteristic pigment changes in the midperiphery closely resembling the fine mottling observed in the initial stage of the disease in males.
Assessment of the REP-1 gene in European and Japanese choroideremia patients has revealed a wide variety of mutations, including gross deletions and point mutations such as nonsense, frameshift, and splice-site mutations. All these mutations are thought to fail in intact REP-1 protein synthesis.


CONCLUSIONS
The recent molecular studies may open a new chapter in the research on choroideremia and provide the groundwork for therapeutic potential as well as diagnosis and genetic counseling.
Ohba
N
N
Department of Ophthalmology, Kagoshima University Faculty of Medicine, Japan.
Isashiki
Y
Y
D048868:Adaptor Proteins, Signal Transducing; D000293:Adolescent; D000328:Adult; D019883:Alkyl and Aryl Transferases; D002352:Carrier Proteins / Q000235:genetics; D002648:Child; D015794:Choroideremia / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D005654:Fundus Oculi; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D017368:Protein Prenylation; D014794:Visual Fields; D020691:rab GTP-Binding Proteins
D048868:Adaptor Proteins, Signal Transducing; C081787:CHM protein, human; D002352:Carrier Proteins; D019883:Alkyl and Aryl Transferases; D020691:rab GTP-Binding Proteins