X-linked retinitis pigmentosa: re-evaluation of fundus findings and the use of haplotype analysis in clarification of carrier female status.
The identification by fundus examination of those females carrying an X-linked retinitis pigmentosa (RP) gene can reportedly be as high as 87%. In genetic counselling sessions with young females with a 50% risk of being a carrier who wished to know their status, it has not been possible to achieve such a level of success. A review and reanalysis of previous reports indicated that if a tapetal-like reflex was not present in those age 35 years or less, the likelihood of identifying a carrier by fundus examination was small. A family with 7 females with a 50% risk of being a carrier of X-linked RP was evaluated using haplotype analysis in an attempt to identify the X chromosome carrying the RP gene. In the family described, it was possible to establish that a mutation in the RP3 locus most likely causes the disease. This has permitted the determination of the carrier status in each of the females with a high degree of certainty.
Bech-Hansen
N T
NT
Molecular Genetics Unit, Alberta Children's Hospital, University of Calgary, Canada.
Pearce
W G
WG
D000293:Adolescent; D000328:Adult; D002648:Child; D004247:DNA / Q000032:analysis; D005260:Female; D005654:Fundus Oculi; D006580:Genetic Carrier Screening; D005817:Genetic Counseling; D008040:Genetic Linkage / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D012174:Retinitis Pigmentosa / Q000209:etiology / Q000235:genetics*; D014960:X Chromosome / Q000235:genetics*
D004247:DNA